[Federal Register: January 24, 2008 (Volume 73, Number 16)]
[Proposed Rules]
[Page 4379-4418]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24ja08-47]
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Part III
Department of the Interior
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Fish and Wildlife Service
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50 CFR Part 17
Endangered and Threatened Wildlife and Plants; 12-Month Finding on a
Petition To List the Siskiyou Mountains Salamander (Plethodon stormi)
and Scott Bar Salamander (Plethodon asupak) as Threatened or
Endangered; Proposed Rule
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[FWS-R8-ES-2008-0002; 1111 FY07 MO;ABC Code: B2]
Endangered and Threatened Wildlife and Plants; 12-Month Finding
on a Petition To List the Siskiyou Mountains Salamander (Plethodon
stormi) and Scott Bar Salamander (Plethodon asupak) as Threatened or
Endangered
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 12-month petition finding.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
12-month finding on a petition to list the Siskiyou Mountains
salamander (Plethodon stormi) and Scott Bar salamander (Plethodon
asupak) as threatened or endangered, under the Endangered Species Act
of 1973, as amended (Act). After a thorough review of all available
scientific and commercial information, we find that listing the
Siskiyou Mountains salamander and Scott Bar salamander is not
warranted. We ask the public to continue to submit to us any new
information concerning the status of, and threats to, these species.
This information will help us to monitor and encourage the ongoing
management of these species.
DATES: We made the finding announced in this document on January 24,
2008.
ADDRESSES: This finding is available on the Internet at http://www.regulations.gov and http://www.fws.gov/yreka/. Supporting
documentation we used in preparing this finding is available for public
inspection, by appointment, during normal business hours at the U.S.
Fish and Wildlife Service, Yreka Fish and Wildlife Office, 1829 S.
Oregon Street, Yreka, CA 96097; telephone 530-842-5763; facsimile 530-
842-4517. Please submit any new information, materials, comments, or
questions concerning this finding to the above address or via
electronic mail (e-mail) at Siskiyou_salamander@fws.gov.
FOR FURTHER INFORMATION CONTACT: Phil Detrich, Field Supervisor, U.S.
Fish and Wildlife Service, Yreka Fish and Wildlife Office (see
ADDRESSES section). If you use a telecommunications device for the deaf
(TDD), call the Federal Information Relay Service (FIRS) at 800-877-
8339.
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.) requires
that, for any petition to revise the Lists of Endangered and Threatened
Wildlife and Plants that contains substantial scientific and commercial
information that listing may be warranted, we make a finding within 12
months of the date of our receipt of the petition on whether the
petitioned action is: (a) Not warranted, (b) warranted, or (c)
warranted, but the immediate proposal of a regulation implementing the
petitioned action is precluded by other pending proposals to determine
whether any species is threatened or endangered. Such 12-month findings
are to be published promptly in the Federal Register. Section
4(b)(3)(C) of the Act requires that we treat a petition for which the
requested action is found to be warranted but precluded as though
resubmitted on the date of such finding, and we must make a subsequent
finding within 12 months.
Previous Federal Actions
On June 18, 2004, we received a petition dated June 16, 2004, from
the Center for Biological Diversity, Klamath-Siskiyou Wildlands Center,
and Noah Greenwald, to list the Siskiyou Mountains salamander
(Plethodon stormi) as a threatened or endangered species on behalf of
themselves and five other organizations. The petition clearly
identified itself as such and included the requisite identification
information for the petitioners, as required in 50 CFR 424.14(a). In
their petition, the petitioners assert that there are three separate
distinct population segments (DPSs) of the Siskiyou Mountains
salamander, one of which consists of the Scott Bar salamander.
Alternatively, the petitioners assert that the Scott Bar salamander is
a separate species and request that it be considered independently for
listing. Since the time the petition was submitted, the Scott Bar
salamander (Plethodon asupak) has been recognized as a species separate
from the Siskiyou Mountains salamander (Mead et al. 2005, pp. 169-171),
and we have reviewed it separately in making this finding. The
petitioners also requested the Service to consider whether the Siskiyou
Mountains salamander (and therefore the Scott Bar salamander, as well)
warrants listing throughout a significant portion of its range, and
requested designation of critical habitat for both species concurrent
with their listing. In a July 19, 2004, letter to the petitioners, we
responded that we reviewed the petition for both species and determined
that an emergency listing was not warranted, and that because of
inadequate funds for listing and critical habitat designation, we would
not be able to otherwise address the petition to list the Siskiyou
Mountains salamander and Scott Bar salamander at that time.
On June 23, 2005, we received a 60-day notice of intent to sue and
on August 23, 2005, the Center for Biological Diversity and four other
groups filed a Complaint for Declaratory and Injunctive Relief in
Federal District Court for the District of Oregon (Center for
Biological Diversity et al. v. Norton et al., No. 3:05-CV-1311-BR),
challenging our failure to issue a 90-day finding on the petition to
list the Siskiyou Mountains salamander and Scott Bar salamander. On
December 28, 2005, we reached an agreement with the plaintiffs to
complete the 90-day finding by April 15, 2006, and if we determined
that the petition presented substantial information that listing may be
warranted, to complete the 12-month finding by January 15, 2007.
On April 17, 2006, the Service made its 90-day finding (71 FR
23886, April 25, 2006), concluding that the petition did not present
substantial scientific or commercial information to indicate that
listing the Siskiyou Mountains salamander and Scott Bar salamander may
be warranted.
On July 6, 2006, the Center for Biological Diversity and others
filed suit in the United States District Court for the Northern
District of California (Center for Biological Diversity et al. v. Dirk
Kempthorne et al., No. C-06-4186-WHA), challenging the merits of that
finding. On January 19, 2007, the District Court determined the 90-day
finding was arbitrary and capricious, vacated and remanded the finding,
and ordered the Service to make a new finding by March 23, 2007.
A new 90-day finding was signed on March 22, 2007, and we published
it in the Federal Register on March 29, 2007 (72 FR 14750). In that 90-
day finding, we concluded that the petition presented substantial
scientific or commercial information to indicate that listing the
Siskiyou Mountains salamander and Scott Bar salamander may be
warranted, announced the initiation of a status review of these taxa,
and solicited comments and information to be provided in connection
with the status review by May 29, 2007. This notice constitutes our 12-
month finding regarding the petition to list these two species.
To ensure that this finding is based on the latest information and
incorporates the opinions of the scientific community, the Service
entered into a
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Cooperative Agreement with the U.S. Geological Survey, Forest and
Rangeland Ecosystem Science Center, in Corvallis, Oregon, to provide a
technical report addressing taxonomy, biology, habitat associations,
detectability, and effects of habitat alteration on the salamanders.
The technical report was authored by Douglas DeGross and R. Bruce Bury,
and reviewed by species experts in the U.S. Geological Survey, Forest
and Rangeland Ecosystem Science Center; U.S. Forest Service (USFS)
Pacific Northwest Research Station and Pacific Southwest Research
Station; and Rogue River-Siskiyou National Forest. The technical report
(DeGross and Bury 2007), information provided by the public, and
additional information and data in our files provided the basis for
this status review for the Siskiyou Mountains salamander and Scott Bar
salamander. In addition, Service staff involved in the development of
this finding have several years of combined experience surveying for
and researching the distribution and habitat associations of Siskiyou
Mountains salamander.
Foreseeable Future
The principal difference between an ``endangered'' and a
``threatened'' species under the Act is whether the species is
currently in danger of extinction, or if it is likely to become so
``within the foreseeable future.'' The Act does not define the term
foreseeable future; however, we consider the foreseeable future to be
affected by the biological and demographic characteristics of the
species, as well as our ability to predict or extrapolate the effects
of threats facing the species in the future. Quantification of the time
period corresponding to the forseeable future is challenging because it
necessitates making predictions about inherently dynamic political,
legal, and social mechanisms that influence the degree and immediacy of
potential threats to the species.
Population dynamics of the Siskiyou Mountains salamander and Scott
Bar salamander are poorly known, and we are unaware of data sufficient
to support estimates of longevity, generation times, or recruitment
rates for these species. For example, Nussbaum et al. (1983, p. 103)
state that both sexes ``are thought to'' mature at 5 to 6 years of age,
but provide no basis for this estimate. Likewise, estimates of
population and genetically effective population (Ne) size
are unavailable for these species (DeGross and Bury 2007, p. 9).
Because the demographic and biological characteristics of these species
are so poorly understood, we must base our estimate of foreseeable
future on our ability to predict or extrapolate the effects of the
future threats facing these species.
Our ability to predict the effects of future threats is limited to
our knowledge of the time frame of the threats potentially facing the
species (e.g., timber harvest, wildfire, roads and road construction,
mining and rock quarrying, disease, stochastic events, and climate
change) and of any conservation activities taking place to address
these threats. For example, the rate of timber harvest has declined on
Federal lands (which constitute over 85 percent of the combined ranges
of both species) during the last 30 years (USDA and USDI 1994, 2005)
and we have no information that would lead us to predict a dramatic
increase in the rate and intensity of timber harvest such that large
areas of habitat will be affected to such a great degree that these
species will suffer adverse impacts. In the event that the rate and
intensity of timber harvesting were to increase dramatically, it would
take some period of time (depending on the actual increase of the rate
and intensity, and the impact of the harvesting at issue on the
salamanders) for the cumulative impact of the timber harvesting to have
a significant effect on the species. Because the available evidence
suggests that the salamanders recover for even intensive disturbances
such as clearcutting (from 11 years (Bull et al. 2006, p. 21) to 30
years (Welsh et al. 2007b) for Siskiyou Mountains salamanders), the
species would only become in danger of extinction if that increased
level and intensity of harvest lasted long enough to effect sufficient
habitat at nearly the same time such that it overcame the apparent
resiliency of the species to such disturbances. Further, while
scientists predict that the rate of temperature change will continue to
increase throughout the present century (EPRI 2003, p. 3; Hayhoe et al.
2004, p. 12423; Cayan et al. 2006, pp. 11-14, 31; Maurer 2007, p. 317),
the effects of climate change on these species are uncertain and
estimation of the timing of potential effects would be speculative.
We do not have sufficient demographic information on Siskiyou
Mountains salamanders or Scott Bar salamanders, nor on the trajectory
of potential threats when combined with existing regulatory mechanisms,
on which to base a precise definition of foreseeable future. Given the
stability of Federal Land and Resource Management Plans and the
Northwest Forest Plan (NWFP) since its establishment in 1994, we assume
that significant changes to current land management practices on
Federal lands are not likely to occur within 20 years. We note that the
changes in Federal land management that we can anticipate may happen in
the short term, including termination of the Survey and Manage Program
and Western Oregon Plan Revision, discussed below, are unlikely to
result in the sort of significant changes that might have an important
effect on the conservation status of the species. If a significant
change were to occur, we estimate that, because of logistical and
regulatory limitations imposed on the rate of planning and implementing
significant land management actions, actual management activities could
take an additional 20 years to reach a magnitude of effect that would
measurably affect salamander populations. Therefore, we conclude that
the foreseeable future for the salamanders does not extend beyond 40
years. In other words, we have sufficient confidence in our estimates
of the threats and reaction of the two species to those threats to draw
a conclusion as to the likelihood of endangerment over only at most 40
years. Beyond that period, our level of confidence is such that any
conclusions we drew would be too speculative on which to base current
action. We find that this estimate of the foreseeable future is both
reasonable and appropriate because it focuses this status review on the
time frame in which current social and political change may affect
species management, which we consider to have the most likely potential
for meaningful near-term influence on the status of these species.
Species Descriptions
Like others in the Family Plethodontidae (the lungless
salamanders), the Siskiyou Mountains salamander and Scott Bar
salamander are completely terrestrial, medium-sized, slender-bodied
salamanders with short limbs and a dorsal stripe. Both species are
found in or near talus (loose surface rock) and fissured rock outcrops
where moisture and humidity are high enough to allow respiration
through their skin (Feder 1983, p. 296; Nussbaum et al. 1983, pp. 73,
90, and 102; Stebbins 2003, p. 168). Both species are endemic to the
Klamath-Siskiyou Mountains of southern Oregon and northern California,
where they are considered as part of a species complex that includes
and is named for the similar Del Norte salamander (Plethodon
elongatus).
Members of the Plethodon elongatus Complex differ physically from
other regional members of the genus
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Plethodon. Species in the Plethodon elongatus Complex have webbed toes,
while Dunn's salamander (P. dunni) and western red-backed salamander
(P. vehiculum) do not (Highton 1962, pp. 255-256). The larger number of
trunk vertebrae and costal grooves (vertical creases along the side of
the body), as well as the smaller number of vomerine teeth (teeth on
the vomer bone in the roof of the mouth) further distinguish the
Plethodon elongatus Complex from the rest of the western Plethodon
species (Highton and Brame 1965, p. 1; Brodie 1970, pp. 503-505;
Nussbaum et al. 1983, p. 102; Mead et al. 2005, pp. 163-166).
The Siskiyou Mountains salamander was described in 1965, two years
after it was first identified (Highton and Brame 1965, p. 1). It is
characterized by a modal number of 17 costal grooves and 4 to 5.5
intercostal folds (folds of skin between the costal grooves) between
the toes of adpressed limbs (limbs firmly pressed against the sides of
the body) (Nussbaum et al. 1983, p. 102; Leonard et al. 1993, p. 78).
Adults have a light- to purplish-brown dorsum, and the body is
sprinkled with a moderate to dense array of white to yellow flecks,
concentrated on the sides and limbs and away from the light-brown
dorsal stripe (Highton and Brame 1965, p. 1; Nussbaum et al. 1983, p.
102). Juveniles are black and have an olive-tan dorsal stripe that
extends onto the tail.
The Scott Bar salamander is more robust and has a wider head and
longer limbs than the Del Norte salamander and Siskiyou Mountains
salamander. It has fewer intercostal folds between adpressed limbs (2.5
to 3.5) than either the Del Norte salamander (5 to 6) or Siskiyou
Mountains salamander (4 to 5.5), and the modal number of costal grooves
(17) is one less than in the Del Norte salamander (18). The Scott Bar
salamander has a longer body relative to its tail length and longer
forelimbs and hindlimbs than the Siskiyou Mountains salamander or Del
Norte salamander. The coloration of the Scott Bar salamander is similar
to that of the Siskiyou Mountains salamander and is described in Mead
et al. (2005, p. 170). Despite the morphological differences described
in Mead et al. (2005, pp. 169-171), the two species are difficult to
distinguish in the field.
Taxonomy
The Siskiyou Mountains salamander was first identified in 1963,
adding the second form to what is now referred to as the Plethodon
elongatus Complex (Highton and Brame 1965, p. 1). Early distinctions
between Siskiyou Mountains salamanders and Del Norte salamanders were
based on morphological traits and coloration (Highton and Brame 1965,
p. 1; Brodie 1970, pp. 503-505; Bury 1973, p. 57). However, it is now
clear that field identification of these species based on coloration is
unreliable because both species exhibit geographic variation in
coloration (Brodie 1970, p. 503; Bury 1999, pp. 9-10).
Researchers have cited morphological differences as evidence of a
taxonomic distinction between Siskiyou Mountains salamanders and Del
Norte salamanders. Perhaps the most convincing support for
distinguishing between these forms was provided by Mead et al. (2005,
pp. 165-166), who found that all three species in the Plethodon
elongatus Complex differed in average measurements of male snout-vent
length, forelimb length, and head width; and female snout-vent length,
forelimb length, and internarial distance. Additionally, both Siskiyou
Mountains salamanders and Scott Bar salamanders have a smaller modal
number of costal folds and proportionally larger forelimbs than Del
Norte salamanders, contributing to their more robust appearance
(Highton and Brame 1965, p. 1; Mead et al. 2005, p. 170).
Phylogenetic studies of the Plethodon elongatus Complex have
provided further support for classifying Siskiyou Mountains salamanders
and Del Norte salamanders as closely related species (Mahoney 2001, p.
183; Mahoney 2004, pp. 155-161; Bury and Welsh 2005, p. 842; Mead et
al. 2005, p. 166). Phylogenetic studies of these species have also
shown that early studies of the morphology of Del Norte salamanders
along the Klamath River between Happy Camp and Seiad Valley,
California, were in fact describing Siskiyou Mountains salamanders
(Pfrender and Titus 2001, p. 15; DeGross 2004, pp. 17-18; Mahoney 2004,
p. 5; Mead et al. 2005, p. 173; Mead 2006, pp. 15-16). In fact, Bury
(1973, p. 57) proposed possible intergradation between these two
species, and Stebbins (1985, p. 47; 2003, pp. 173-174) demoted the
Siskiyou Mountains salamander to a subspecies of Del Norte salamander.
However, recent research suggests that little gene flow occurs between
these species across their zone of contact in the Indian Creek drainage
in western Siskiyou County, California (DeGross 2004, p. 40; DeGross et
al. unpublished).
Phylogenetic studies of the Siskiyou Mountains salamander have
indicated that this species consists of two distinct genetic lineages:
North Clade (populations within the Applegate River drainage and on the
crest of the Siskiyou Mountain Range) and South Clade (populations
south of the Siskiyou Mountain Range crest and adjacent to the Klamath
River) (Pfrender and Titus 2001, pp. 5-6; DeGross 2004, pp. 24-44;
Mahoney 2004, p. 8; Mead et al. 2005, pp. 163-166). A third, more
divergent, group was also identified and is now recognized as a
separate species, the Scott Bar salamander.
Based on levels of genetic divergence between species in the
Plethodon elongatus Complex, researchers estimated that the Del Norte
salamander and Siskiyou Mountains salamander lineages diverged
approximately 4 million years ago and that their shared ancestral
lineage diverged from that of the Scott Bar salamander between 20 and
26 million years ago (Mahoney 2004, p. 15; Mead et al. 2005, p. 165).
Therefore, the Scott Bar salamander lineage appears to be the basal
(most primitive, from which others are derived) lineage of the
Plethodon elongatus Complex. Given the time periods during which these
species diverged, speciation within this complex was probably
influenced by Pleistocene glaciation (Soltis et al. 1997, pp. 369-370;
Bury 1999, p. 22; DeGross and Bury unpublished).
Differences between Scott Bar salamanders and the other members of
the Plethodon elongatus Complex are not limited to their genetic
divergence. As noted above, Mead et al. (2005, pp. 165-166) found
differences in morphological measurements of all three species.
Nonetheless, questions about the validity of the current classification
of these species persist (sensu Wake and Jockusch 2000, p. 117).
Further, the ranges of the Scott Bar salamander and Siskiyou Mountains
salamander abut each other north of the Klamath River and south of
Horse Creek, so it is possible that these species interbreed in this
area. Measurements of gene flow between these species would be helpful
to further clarify the taxonomy of southern populations of Siskiyou
Mountains salamanders and Scott Bar salamanders and define the
interspecific boundaries for each species range (DeGross and Bury 2007,
p. 4; Wake and Jockusch 2000, p. 117).
The Service recognizes that questions about the taxonomy of the
Plethodon elongatus Complex remain and that research on this topic is
ongoing. However, for the purpose of this finding, we evaluated the
threats to the Siskiyou Mountains salamander and Scott Bar salamander
separately because the preponderance of available evidence currently
supports recognition of these forms as separate species. Even so, the
ecological research on these species was
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conducted prior to recognition of the Scott Bar salamander as a
separate species, and since both species are members of the Family
Plethodontidae, their life histories and habitat associations appear to
be similar. Therefore, for the purpose of this finding, we use the
current literature describing the biological characteristics and
ecology of the Siskiyou Mountains salamander for both species.
For the purposes of this finding, we use the following hierarchy of
taxonomic names:
(1) Plethodon elongatus Complex: Plethodon salamanders within the
geographic region occupied by Del Norte salamander, Siskiyou Mountains
salamander, and Scott Bar salamander.
(2) Siskiyou Mountains salamander Complex: The three known genetic
entities previously classified as Siskiyou Mountains salamander,
consisting of the Scott Bar salamander, Siskiyou Mountains salamander
North Clade, and Siskiyou Mountains salamander South Clade.
(3) Siskiyou Mountains salamander (North and South Clades
combined), not including the Scott Bar salamander.
(4) Individual genetic subunits of Siskiyou Mountains salamander:
North Clade (hereafter referred to as the Applegate salamander) and
South Clade (hereafter referred to as the Grider salamander).
Biology
Like other members of the Family Plethodontidae, Siskiyou Mountains
and Scott Bar salamanders require contact with moisture for respiration
through their permeable skin (Feder 1983, pp. 292-293). Desiccation is
lethal to Plethodon species and therefore, surface activity by Siskiyou
Mountains and Scott Bar salamanders primarily occurs at night, when the
air is cool and moist (Nussbaum 1974, p. 3; Nussbaum et al. 1983, p.
103; Clayton and Nauman 2005, p. 139; Mead et al. 2005, p. 118). Peak
periods of surface activity occur during the rainy season (usually late
fall and spring) (Clayton and Nauman 2005, p. 139; Mead et al. 2005, p.
118). These salamanders retreat to underground refugia during the
extreme climatic conditions common during summer and winter in the
eastern Klamath Mountains (Nussbaum 1974, p. 3). They may forage at the
surface during the summer (Nussbaum et al. 1983, p. 103) but probably
only in sites with relatively cool, moist microclimates. Little is
known about these species' behavior, but many researchers assume that
they are inactive underground and that foraging and reproduction only
occur during brief periods of surface activity (Feder 1983, p. 305).
However, it is possible that these activities also occur below the
surface (Welsh and Lind 1992, p. 433). The limited surface activity by
these species is reflected in survey protocols for Siskiyou Mountains
salamanders, which require that surveys be restricted to periods of
relative humidity above 65 percent, air temperatures between 39.2 and
68 [deg]F (4 to 20 [deg]C), soil temperatures between 38.3 and 64.4
[deg]F (3.5 to 18 [deg]C), and moist soil conditions (Clayton et al.
1999, p. 133).
Plethodon salamanders are fully terrestrial amphibians and do not
need standing or flowing water for any stage of their life cycle (Zug
et al. 2001, p. 383). Eggs are thought to be laid in small clusters
deep in moist, rocky substrates, but this has not been observed by
researchers. Females have clutches of 2 to 18 eggs, with an average of
9 eggs per clutch (Nussbaum et al. 1983, pp. 21-23). Juveniles emerge
in late fall and early spring. Welsh and Lind (1992, p. 432) reported
that juveniles captured in mid-spring were significantly larger than
would be expected if newly hatched. These salamanders appear to become
reproductively mature at 5 to 6 years and are relatively long-lived (up
to 15 years) (Nussbaum et al. 1983, p. 103; Clayton and Nauman 2005, p.
139). Females appear to breed every other year (Nussbaum 1974, p. 22).
Siskiyou Mountains and Scott Bar salamanders are `lie-and-wait'
predators that prey on a variety of small terrestrial invertebrates,
including spiders, pseudoscorpions, mites, ants, collembolans, and
beetles (Nussbaum et al. 1983, p. 103). Seasonal changes in diet have
been reported for these species (Nussbaum 1974, p. 24). Predators of
these species have not been identified but may include snakes, shrews,
or animals that opportunistically forage in spring leaf litter and
debris (e.g., ground-foraging birds). Several researchers have
hypothesized that interspecific and intraspecific competition are
important factors in the population ecology of Siskiyou Mountains and
Scott Bar salamanders (Nishikawa 1985, p. 1290; Mathis 1989, p. 790;
Griffis and Jaeger 1998, p. 2500). These species' ranges overlap with
those of ensatina (E. eschscholtzii oregonensis) and black salamanders
(Aneides flavipunctatus), and a recent study described one site where
they are sympatric with Del Norte salamanders (Mead 2006, p. 8). We are
not aware of any information about parasites or diseases affecting
these species or information about symbiotic or mutualistic
interactions with other organisms.
Habitat Associations
Siskiyou Mountains salamanders and Scott Bar salamanders occur on
slopes with rocky soils or talus (loose surface rock) outcrops. These
substrates provide interstitial spaces into which these animals can
retreat from the climatic extremes of the eastern Klamath Mountains.
These salamanders are occasionally found under other types of cover,
such as bark, limbs, or logs, but only during wet weather when moisture
is high and only in close proximity to suitable rocky substrates
(Nussbaum 1974, p. 13; Nussbaum et al. 1983, p. 102). Like other
plethodontids, Siskiyou Mountains salamanders and Scott Bar salamanders
require contact with moisture for respiration through their skin.
Therefore, habitat characteristics that influence forest microclimates,
especially relative humidity and soil surface moisture, are likely
important to these species. Based on these species' similar natural
histories and physiologies (see ``Biology'' section), occurrence in the
same region, and previous designation as one species, we assume that
Siskiyou Mountains salamanders and Scott Bar salamanders have similar
habitat requirements. As noted above, nearly all of the available
information on these species comes from studies conducted on both
species, prior to recognition of Scott Bar salamander as a separate
species.
Early observational studies of Siskiyou Mountains salamanders found
that these animals are highly associated with talus and other rocky
substrates (Highton and Brame 1965, p. 1; Storm 1966, p. 1; Nussbaum
1974, p. 13; Clayton and Nauman 2005, p. 139; Mead et al. 2005, p.
118). Nussbaum (1974, p. 13) found that the densest populations were on
heavily wooded, north-facing slopes that also had talus deposits or
fissured rock outcrops. Many of the earliest known populations of
Siskiyou Mountains salamanders occurred in talus road cuts, where the
underlying rock substrate was exposed and detection of salamanders was
facilitated (Nussbaum 1974, p. 13).
The degree to which Siskiyou Mountains salamanders and Scott Bar
salamanders are associated with late-seral forest conditions has been
the subject of considerable uncertainty and debate among scientists and
land managers. Understanding this debate is essential to understanding
the Service's finding for these species. The debate is exemplified by
the salamander population at Muck-a-Muck Creek, the type locality from
which the Scott Bar salamander was described (Mead et al. 2005, p.
169). Biologists and researchers
[[Page 4384]]
use Muck-a-Muck as a ``reference site,'' a location with reliable
salamander detections that can be checked prior to conducting surveys
in other nearby areas to confirm that current weather conditions are
within proper limits to conduct these surveys. However, even when
survey conditions are adequate, salamanders may not be detected at this
known reference site on any given single visit. Located adjacent to a
road, the site experienced hydraulic mining in the late 1800s and
currently supports a sparse overstory of young and early mature trees.
These habitat conditions are representative of habitat at many
locations occupied by apparently viable populations of Siskiyou
Mountains salamanders (Bull et al. 2006, pp. 19-22; CDFG 2005, p. 24;
Farber 2007a, pp. 3-4). The regularly reported existence of salamander
populations at sites like the Muck-a-Muck Creek site undercuts the
conclusion of some researchers (based on the results of a single study)
that the species is dependent on old-growth forest (Ollivier et al.
2001, pp. 26-29; Welsh et al. 2007a, p. 31).
The results of studies of habitat relationships conducted to date
are equivocal or provide limited inferences. Limited inferences result
from either (1) lack of a random or systematic sampling design that
allows inference to a larger population, or (2) single-visit sampling
that fails to incorporate the low and variable detection rates
associated with these species. Two analyses of a single, relatively
large-scale, single-visit, random, sampling-based study suggested an
association with closed-canopy, older forest (Ollivier et al. 2001;
Welsh et al. 2007a), whereas field studies evaluating habitat
attributes at known (not randomly or systematically selected) locations
demonstrated that the species are found in a wide range of forest
structural conditions (Farber et al. 2001; Bull et al. 2006; Farber
2007a). We are not aware of any rigorous studies evaluating the
species' demographic responses to forest conditions.
The most rigorous research of these species' habitat associations
was conducted by Ollivier et al. (2001) and Welsh et al. (2007a). These
studies used the same data set and somewhat different analytical
techniques. The data used in both analyses were collected at 61 sites
occupied by Siskiyou Mountains salamanders and possibly Scott Bar
salamanders (a few sites were located within the range of what were
later recognized as Scott Bar salamanders). These sites were compared
with sites classified as unoccupied by salamanders (see below). These
studies found that salamander populations on either side of the
Siskiyou Crest appeared to occupy habitat based on different
environmental factors (Welsh et al. 2007a, p. 28). The authors
primarily attributed this result to geographic differences in
precipitation, illumination (topographic variation in sunlight or
shading), and vegetation (Welsh et al. 2007a, pp. 19, and 28). Based on
these differences, they suggested that suitable habitat is less
abundant and more patchily distributed on the south side of the crest
than on the north side (Welsh et al. 2007a, p. 28). Although these
results differed somewhat for salamanders on either side of the
Siskiyou Crest, they generally indicated that sites occupied by
salamanders contained attributes that likely moderate surface
microclimates for these animals (e.g., greater canopy closure, more
leaf litter cover, more decaying logs) or that are associated with
moist, cool microclimates (e.g., less grass cover, more sword fern
cover) (Ollivier et al. 2001, pp. 17-21, 26-29; Welsh et al. 2007a, pp.
24, 27). Both analyses concluded that Siskiyou Mountains (and possibly
Scott Bar) salamanders are ``a mature to old-growth-forest-associated
species that exists at its biological optimum under conditions found
primarily in later seral stages of mixed conifer-hardwood forests in
northwestern California and southwestern Oregon'' (Ollivier et al.
2001, p. 42; Welsh et al. 2007a, p. 31). However, the authors also
state that ``[t]oday, information on the habitat requirements of this
species is incomplete and conflicting'' (Welsh et al. 2007a, p. 16) and
``[m]any of the biotic and abiotic requirements necessary for long-term
viability for the Siskiyou Mountains salamander remain undetermined''
(Welsh et al. 2007a, p. 31). It is important to note that the results
of these studies only indicate correlations between forest attributes
and the presence of salamanders; they do not actually demonstrate that
these species select habitat based on older-forest characteristics
(Welsh et al. 2007a, p. 31). For example, these salamanders may select
habitat based on other factors (e.g., suitable microclimates) that
often occur within older forests but that can also occur in other areas
such as deep drainages and north-facing slopes.
Our understanding of the habitat associations of Siskiyou Mountains
salamander and their degree of ecological dependence on specific
habitat conditions is hampered by the difficulty in detecting this
species during surveys. Their brief, intermittent periods of surface
activity, nocturnal habits, and secretive behavior make detection of
Siskiyou Mountains salamanders and Scott Bar salamanders difficult
(Nussbaum 1974, p. 3; Olson et al. 2007, pp. 7-8). Welsh et al. (2007a,
p. 25) estimated that their detection rates for these species were 20
and 28 percent on the south and north slopes of the Siskiyou Crest,
respectively. Detection rates for other Plethodon species are similarly
low: 15 percent (Bailey et al. 2004, p. 21) and 2 to 32 percent (Taub
1961, p. 695). Because detection rates are low for these species,
repeated surveys and estimation of the probability of false negatives
during surveys are required to minimize or account for the probability
of classifying occupied sites as unoccupied. The survey protocol
developed for the NWFP Survey and Manage Guidelines (Clayton et al.
1999, p. 141) requires three survey visits to determine presence or
absence of Siskiyou Mountains salamanders. Classifying occupied sites
as unoccupied, or failing to account for the probability of doing so,
can bias conclusions about relationships between salamanders and
habitat characteristics. The presence or absence data analyzed by
Ollivier et al. (2001) and Welsh et al. (2007a) were collected with a
single-visit protocol, so these studies cannot reliably infer absence
at sites where detections were not obtained. In fact, the California
Department of Fish and Game (CDFG) used a more intensive survey
protocol to resurvey 13 clear-cut or precanopy (0 to 30 years-old)
sites classified as unoccupied by Ollivier et al. (2001) and Welsh et
al. (2007a) and found Siskiyou Mountains salamanders at 5 sites, Scott
Bar salamanders at 2 sites, and Del Norte salamanders at 1 site (Bull
et al. 2006, p. 25). While this finding does not appear to change the
general conclusion described by Ollivier et al. (2001) and Welsh et al.
(2007a) that salamanders were more likely to be detected in closed-
canopied older forest than in more open sites, it acts to substantially
weaken the inference of Ollivier et al. (2001, p. 42) and Welsh et al.
(2007a, p. 31), that these species are ecologically dependent on
conditions primarily found in mature or late-seral stage forests.
Two other studies have examined potential relationships between
habitat attributes and abundances of Siskiyou Mountains salamanders and
Scott Bar salamanders. Farber (2007a) described sites occupied by Scott
Bar salamanders on private timber company property and adjacent
National Forest land. This study compared salamander abundances and
habitat characteristics at 26 sites
[[Page 4385]]
within a relatively small area (29 acres (ac) (11.7 hectares (ha))) and
found that salamander abundance was only significantly related to
percent rock cover. A large proportion of the occupied sites (94
percent) had evidence of at least one previous manmade or natural
disturbance (Farber 2007a, p. 3). Bull et al. (2006) described CDFG
surveys at 68 sites occupied by Siskiyou Mountains or Scott Bar
salamanders. Eighty-seven percent of these sites were on private
timberlands, and the remaining sites were on Federal lands (Bull et al.
2006, p. 24). Like Farber (2007a), CDFG found evidence of previous
disturbance at most (82 percent) occupied sites (Bull et al. 2006, p.
24). Roughly 83 percent of the sites occurred in forest stands with
relatively open canopies (less than 60 percent canopy closure). They
also found that salamander sites occurred within a wide range of
environmental conditions, including all slope aspects and nearly all
(16 of 18) California Wildlife Habitat Relationships tree size and
canopy classes (Bull et al. 2006, p. 24). These studies' sampling
designs preclude inferences about the habitat preferences of other
Siskiyou Mountains salamander populations because they were focused on
known salamander sites and did not take into account the broad range of
habitat that is potentially available to these salamander species.
However, both studies showed that Siskiyou Mountains salamanders and
Scott Bar salamanders occur within a relatively wide range of forest
conditions, and were not extirpated by the disturbances (timber
harvest) that created those conditions.
To support their argument that the Siskiyou Mountains salamander is
critically imperiled by habitat loss, the petitioners rely heavily on
statements made by Welsh et al. (2007a) as providing new scientific
information that the salamanders are highly associated with, and
ecologically dependent on, old-growth forest conditions, and the
petitioners highlight an ongoing debate between Dr. Welsh and the CDFG
(Greenwald and Curry 2007, pp. 4-7). As discussed above, we conclude
that the survey methodology employed by Ollivier et al. (2001) and
Welsh et al. (2007a, p. 18) was inadequate to rigorously determine
salamander absence as required for the presence-absence statistical
modeling method used to analyze the data. The single-visit sampling
methodology these authors employed is more appropriate for comparisons
of relative abundance among habitat types, which is how we interpreted
their results. The fact that salamanders were subsequently detected by
CDFG at over half of the `absent' sites analyzed by Welsh et al.
(2007a) does not negate the importance of this study or the habitat
associations it describes; it does, however, limit the strength of
inference regarding the degree to which Siskiyou Mountains salamanders
may require old-growth forest conditions. We do not consider the field
studies conducted by CDFG (Bull et al. 2006) as providing competing
scientific research requiring reconciliation with the statistical
design of the Welsh et al. (2007a) study. The CDFG field studies do,
however, provide habitat results from a large sample of occupied
salamander locations, which, in combination with similar data sets from
Farber et al. (2001), constitute a significant source of information on
these species.
A model was recently developed for predicting the occurrence of
Siskiyou Mountains salamanders north of the Siskiyou Crest (Reilly et
al. 2007). This model incorporated three variables reported by Ollivier
et al. (2001) and Welsh et al. (2007a) to be positively related to
occupancy by Siskiyou Mountains salamanders: rocky soil types, forest
canopy closures above 70 percent, and conifer forest with average tree
sizes greater than 17 inches (43 centimeters) in diameter at breast
height (DBH) (Reilly et al. 2007, p. 1). An additional variable
modeling topographical variation in sunlight or shading was also
incorporated (Reilly et al. 2007, p. 2). Strategic surveys of sites
that were predicted by the model to be occupied had 65 percent
detection rates (34 of 52 sites were occupied), the highest ever
reported for this species (Nauman and Olson 2004, p. 3). In addition to
indicating the usefulness of presence or absence modeling as a
scientific and management tool, this relatively high detection rate
seems to support the associations described by Ollivier et al. (2001)
and Welsh et al. (2007a).
Summary of Habitat Associations
Few studies of the habitat associations of Siskiyou Mountains
salamanders and Scott Bar salamanders have been conducted. These
include only a single large, systematic sample effort, from which two
analyses were conducted (Ollivier et al. 2001 and Welsh et al. 2007a).
These analyses found positive relationships between detection of
Siskiyou Mountains salamanders (and possibly Scott Bar salamanders) and
habitat characteristics that likely moderate surface microclimates for
them (e.g., high canopy closure, more leaf litter cover, more decaying
logs). Studies by Farber et al. (2001), Farber (2007a), and CDFG (Bull
et al. 2006) were smaller and less rigorous than the analyses by
Ollivier et al. (2001) and Welsh et al. (2007a). However, they clearly
showed that Siskiyou Mountains salamanders and Scott Bar salamanders
occur within a wide range of habitat conditions, including clear-cuts
and young forest. The limited available evidence suggests that these
species are highly associated with talus and fissured rock outcrops and
are generally associated with moist, cool surface microclimates. These
salamanders are likely more common in mature and old-growth forest than
in other forest classes, but many salamander sites occur in other
habitat types. Potential differences in the size and viability of
populations in open or disturbed habitat and mature or old-growth
habitat are discussed below under Factor A.
Range and Extant Distribution
Range
Currently known populations within the Siskiyou Mountains
salamander Complex occur within Jackson County and the extreme
southeast portion of Josephine County in southwestern Oregon, and in
northern Siskiyou County in northwestern California. In Oregon, known
populations occur in the Applegate Valley watershed north of the
Siskiyou Crest. In California, the species complex occurs in the
Klamath River drainage, south of the Siskiyou Crest, in the area
bounded to the west by Indian Creek and the headwaters of Grider Creek,
Kelsey Creek, and Canyon Creek; to the south by Scott Bar Mountain; and
to the east by the headwaters of Mill Creek and the Horse Creek
drainage. This range is subdivided into three areas based on
genetically distinct populations. Siskiyou Mountains salamander North
Clade (or Applegate Population) occupies the area north of the Siskiyou
Crest; Siskiyou Mountains salamander South Clade (or Grider Population)
occurs south of the Siskiyou Crest; and the Scott Bar salamander is
found in the southeastern portion of the former range of Siskiyou
Mountain salamander South Clade.
Boundary lines for the ranges of the members of the Siskiyou
Mountains salamander Complex have been variously estimated by several
authors (DeGross 2004, p. 15; Nauman and Olson 2004, p. 2; 2007, p. 4)
and have changed through time as additional populations were discovered
and results of genetic analyses were obtained. For the purposes of this
finding, we delineated species' ranges and calculated landscape
statistics based on
[[Page 4386]]
range boundaries proposed by Nauman and Olson (2007, p. 4) but we
slightly modified these boundaries based on new species locations,
watershed boundaries, and distribution of suitable habitat. Based on
the locations of genetic samples of Scott Bar salamanders, we estimated
its range to incorporate the southeastern portion of the former
Siskiyou Mountains salamander's range. However, the uneven distribution
of surveys and small number of locations with genetic confirmation
creates uncertainty as to the actual extent of the Scott Bar
salamander. The resulting estimated range (136,740 ac (55,335 ha)) is
considerably larger than previous estimates that were based on a small
number of genetically confirmed locations; some of this expansion is
the result of confirmation of one Scott Bar salamander location in the
Walker Creek drainage (DeGross 2007). Several watersheds in the
southern portion of the estimated range delineated by Nauman and Olson
(2007, p. 4) do not have records of Siskiyou Mountains or Scott Bar
salamander locations. Review of these areas by species experts (Cuenca
2007; Clayton 2007) indicated that surveys have not been conducted
there, but suitable habitat is widespread. Additional surveys and
genetic analyses are necessary to adequately delineate the southern
boundary of the Scott Bar salamander and Siskiyou Mountains salamander.
Our estimates of species' ranges are intended for use in evaluating
species' distribution across various land ownership and Federal land
allocations; they are not intended to represent precise estimates of
occupied habitat.
Our understanding of the range and distribution of the Siskiyou
Mountains salamander Complex is dynamic; the known range has roughly
tripled between 1980 and 2007, doubling between 1993 and 1998 (Olson et
al. 2007, p. 20). Biologists familiar with the species believe that the
currently known range is well-defined to the east by xeric conditions
and unsuitable soil types, and to the west by the range of the Del
Norte salamander (Olson et al. 2007, p. 19). However, it is likely that
the known range will continue to be refined and expanded through
discovery of additional populations to the south in the Scott River,
Canyon Creek, Kelsey Creek, and Upper Grider Creek drainages, and to
the north in the Applegate River drainage. For example, two detections
of salamanders described as Siskiyou Mountains salamanders were
reported by a Survey and Manage Guidelines survey crew near the town of
Rogue River in 2006 (DeGross 2007). If confirmed, these detections
would represent a range expansion of roughly 5 miles (mi) (8.45
kilometers (km)).
We were unable to find any information suggesting that the occupied
range of any member of the Siskiyou Mountains salamander Complex is
different from its historical range. Many occupied locations exist
within watersheds that have sustained considerable physical
modification by historical mining, roadbuilding, and logging. As
described above, the species' ranges appear to be defined by climatic
conditions, soil and parent material type, and the adjacent Del Norte
salamander (Olson et al. 2007, p. 19).
Distribution
The distribution of Siskiyou Mountains and Scott Bar salamander
populations within their respective species' ranges is poorly known.
With the exception of systematic surveys conducted by Ollivier et al.
(2001) and Nauman and Olson (2004a and 2004b), the majority of surveys
have been opportunistic or conducted in support of timber management
planning activities. Large areas within the species' known ranges
remain unsurveyed due to poor access or lack of planned projects
requiring surveys. The lack of systematic surveys may result in biased
estimates of population distribution. For example, because CDFG
requires surveys for Siskiyou Mountains salamanders and Scott Bar
salamanders during the Timber Harvest Plan (THP) review process, a high
proportion (40 percent) of known Scott Bar salamander locations have
been reported on private timberlands, which accounts for only 22
percent of the known range of the species (see Table 1 below).
Table 1.--Proportion of Land Ownership Within the Estimated Ranges of Siskiyou Mountains Salamanders (SMS) and
Scott Bar Salamanders (SBS)
----------------------------------------------------------------------------------------------------------------
Scott Bar
Applegate Grider SMS salamander SMS-SBS
SMS (%) (%) (%) complex (%)
----------------------------------------------------------------------------------------------------------------
Private Lands............................................... 15 9 22 15
Federal Lands:
USFS.................................................... 66 91 78 76
BLM..................................................... 19 0 0 9
Total Area (ac)..................................... 248,870 174,285 136,740 559,895
Total Area (ha)..................................... 100,712 70,529 55,335 226,578
----------------------------------------------------------------------------------------------------------------
Population distribution is strongly influenced by the abundance and
distribution of suitable talus habitat. Using a Geographic Information
System (GIS)-based predictive model, the Survey and Manage Guidelines
Species Review Panel for Siskiyou Mountains salamanders estimated that
roughly 30 percent of the known range north of the Siskiyou Crest
consisted of high-quality talus habitat (USDA and USDI Species Review
Panel 2002), but pre-disturbance surveys conducted in the same area
found that 3 to 14 percent of a given planning area (10,000 to 15,000
ac (4,047 to 6,070 ha)) consisted of suitable rock substrate (USDA and
USDI Species Review Panel 2001). Based on surveys and mapping of rock
habitat, Timber Products Company estimated that approximately 18
percent of their surveyed lands within the range of the Scott Bar
salamander was composed of suitable talus habitat (Farber 2006). Using
a similar methodology, Fruit Growers Supply Company (2007) estimated
that 19 percent of 2,615 ac (1,058 ha) surveyed within the range of the
Applegate Population of the Siskiyou Mountains salamander was composed
of suitable talus habitat.
The Siskiyou Mountains salamander Complex occurs within a roughly
500,000 ac (202,346 ha) area dominated by Federal lands (see Table 1).
The range of the Applegate Population (North Clade) of the Siskiyou
Mountains salamander occurs within 248,870 ac (100,712 ha), consisting
primarily (85 percent) of Federal lands, and more than 90 percent of
the 174,285 ac (70,529 ha) range of the Grider Population (South Clade)
of the Siskiyou Mountains salamander occurs on Federal lands (see
[[Page 4387]]
Table 1). The Scott Bar salamander has the smallest range, covering
approximately 136,740 ac (55,335 ha), and occurs on the smallest
proportion of Federal lands (78 percent) within the complex (see Table
1).
Known populations appear to be well-distributed across their
respective species' ranges. To evaluate spatial distribution of
salamander locations within each species' range at a coarse scale, we
compared known locations to watershed boundaries within each species'
range. Site locations of the Applegate Population of the Siskiyou
Mountains salamander occur within 19 of the 21 watersheds that
constitute the range of this group. The range of the Grider Population
of the Siskiyou Mountains salamander is composed of 36 watersheds of
which 23 (64 percent) contain known populations. The 13 watersheds
without known salamander locations are primarily situated in Wilderness
and Roadless areas where access is difficult and few surveys have been
conducted. Known locations of Scott Bar salamanders occupy 17 of the 25
watersheds within their range. Of the eight watersheds without known
locations, six are within Wilderness and Roadless areas where suitable
habitat exists but surveys have not been conducted.
Nauman and Olson (2007) conducted surveys at a stratified random
sample of points located on Federal lands within the range of the
Grider Population of the Siskiyou Mountains salamander and the Scott
Bar salamander. They found occupancy rates (presence or absence) to be
similar at high-elevation (greater than 4,000 feet (ft) (1,219 meters
(m)) sites and low-elevation (less than 4,000 ft (1,219 m)) sites, but
relative abundance (captures per person, per hour) at low-elevation
sites was roughly twice that at high elevation. The authors conducted a
single survey visit per site during one season, and did not evaluate
the potential effect of variable detection probabilities at different
elevations on their results, which, as noted above, may underestimate
the number of animals actually present; however, their findings suggest
that these salamanders may be less abundant or less detectable at
higher elevations.
Population Size and Trend
Evaluation of potential population sizes for the Siskiyou Mountains
salamander and Scott Bar salamander is strongly influenced by the
species' low detectability and the amount and distribution of
potentially suitable habitat. Because of their secretive habits,
detection rates for these salamanders are very low, even though the
species may be locally quite abundant (Nussbaum 1974, p. 3; Clayton et
al. 1999, p. 133). Results of surveys within habitat known to be
occupied are frequently negative (Clayton et al. 2004, p. 10; CDFG
2005, p. 10). Individual populations likely range in size from a few
individuals to thousands of individuals (Nussbaum 1974, p. 16; Welsh
and Lind 1992, p. 96). Based on extrapolation of salamander densities
obtained during intensive field surveys, Nussbaum (1974, p. 16)
provided a species-wide ``conservative estimate'' of over 3 million
Siskiyou Mountains salamanders, and opined that the actual abundance
could be 10 times as high. While the author acknowledged that a number
of methodological problems may affect this estimate, it nonetheless
suggests that the perceived rarity of this species may be more related
to low detectability than to actual population size.
Our current understanding of population sizes for Siskiyou
Mountains salamander and Scott Bar salamander is based primarily on the
cumulative number of occupied sites or locations that have been
reported over time. However, these numbers may be misleading for
several reasons. At many locations, particularly sites detected during
project surveys under Survey and Manage Guidelines, no attempt was made
to determine population size; detection of a single individual was
adequate to define an occupied site. Because of this, large habitat
patches potentially supporting many individual salamanders are counted
as equivalent to small habitat patches or detections of dispersing
individuals. In addition, large areas of suitable habitat remain
unsurveyed, particularly in Wilderness, Roadless Areas, and Late-
successional Reserves where access is poor or project surveys are
typically not conducted (Late-successional Reserves are a NWFP land
allocation designed to serve as habitat for late-successional- and old-
growth-related species). For example, approximately 10 percent and 26
percent of the range of the Scott Bar salamander and Grider salamander,
respectively, is classified as ``Roadless Area.'' Finally, known
locations are frequently spatially clumped, and no uniform effort to
distinguish between individual populations has been undertaken.
Agencies and researchers involved with these species employ several
criteria (e.g., 164 to 492 ft (50 to 150 m) spacing, presence of
perennial stream or area of unsuitable habitat) to imply separation
between occupied locations or ``populations.'' For these reasons, the
currently known numbers of Siskiyou Mountains salamanders and Scott Bar
salamanders are more representative of the distribution and intensity
of survey efforts than of actual salamander populations.
The numbers of known locations of Siskiyou Mountains salamanders
and Scott Bar salamanders have increased steadily since the discovery
of these species. For example, the number of known locations of Scott
Bar salamanders on lands managed by Timber Products Company increased
from 8 in 1997 to 36 in 2007 (Farber 2007c). To describe the number and
distribution of known salamander locations, we obtained location data
from Federal and State agencies and private timber companies and
combined them into a single GIS layer. Because of variability in
methods used by various agencies to delineate individual locations
(many locations were clumped less than 328 ft (100 m) apart), we
evaluated the proximity of adjacent locations and retained only
locations greater than 328 ft (100 m) apart, to minimize the inclusion
of multiple records at discrete locations. The resulting numbers are
intended to represent individual populations, but likely still contain
multiple records from large habitat patches and likely differ from
previous estimates based on dissimilar mapping methods.
Within each of the genetic subunits in the Siskiyou Mountains
salamander Complex, the number of locations with individuals that have
been genetically confirmed to the species level is much smaller than
the overall number of known locations. For example, the estimated range
of the Scott Bar salamander is defined on the basis of 23 genetically
confirmed locations from the samples of Mahoney, Mead, and DeGross;
however, the defined range of the species contains 98 additional
salamander locations previously attributed to the Grider salamander.
Because populations of the two species tend not to overlap (Mead 2006,
p. 10), it is reasonable to conclude that all salamander detections
within what is now known to be the range of the Scott Bar salamander
are Scott Bar salamanders. For the purposes of this finding, we used
the total number of individual locations within each species' range,
recognizing that ongoing genetic studies may modify the boundaries of
these subunits, and therefore the number of known individual sites
within each genetic subgroup.
[[Page 4388]]
Table 2.--Number of Known Locations and Percent of Total Known Siskiyou Mountains Salamanders (SMS) and Scott
Bar Salamanders (SBS) on Federal and Private Lands
----------------------------------------------------------------------------------------------------------------
Scott Bar SMS-SBS
Applegate SMS Grider SMS salamander \1\ complex
----------------------------------------------------------------------------------------------------------------
Federal lands................................... 376 (85%) 74 (97%) 69 (60%) 519 (82%)
Private Lands................................... 64 (14%) 2 (3%) 46 (40%) 112 (18%)
---------------------------------------------------------------
Total....................................... 440 76 115 631
----------------------------------------------------------------------------------------------------------------
\1\ Number of known Plethodon sp. locations within the presumed range of the Scott Bar salamander.
Density
Population densities for the Siskiyou Mountains salamander Complex
are poorly known. Estimation of population density for these
salamanders is hindered by low detectability and highly variable
environmental or habitat conditions during surveys (Nussbaum 1974, p.
15). Densities recorded during the habitat associations study conducted
by Ollivier et al. (2001, p. 16) ranged from 1 to 13 animals per 527-
ft\2\ (49-m\2\) search plot (i.e., 0.02 to 0.33 animals per m\2\);
whereas Nussbaum (1974, p. 16) recorded 0.53 animals per m\2\ during an
intensive field study. Nauman and Olson (2007, p. 19) reported an
average of 0.01 salamanders per m\2\ and 2.39 salamanders per person,
per hour in California, with capture rates ranging from 2.83
salamanders per person, per hour at lower elevations to 1.25
salamanders per person, per hour at higher elevation sites. An
inventory of all known Siskiyou Mountains salamander sites on the
Applegate Ranger District in 1992 reported abundances of salamanders
ranging from 0.3 to 11 salamanders per person, per hour (Olson et al.
2007, p. 13). None of these studies was designed to estimate salamander
density, and mark-recapture studies that would permit estimation of
density have not been conducted.
Population Trend
We were unable to locate any information describing population
trends for the Scott Bar salamander or Siskiyou Mountains salamander
(or either of its constituent populations). Several authors have
inferred population declines based on observations of habitat
modification within occupied areas (Ollivier et al. 2001, p. 5; Welsh
2005, pp. 5-7), but their study design did not support this type of
inference.
Land Management
Populations of Siskiyou Mountains salamanders and Scott Bar
salamanders receive an added layer of security from several
conservation efforts on Federal lands. The majority of the Siskiyou
Mountains salamander Complex occurs within lands administered under the
provisions of the NWFP (USDA and USDI 1994) (see Table 1 above), which
was established to provide an ecosystem-based management strategy for
late-successional forests and the wildlife species that inhabit them
(USDA and USDI 1994). The NWFP consists of two primary parts that
concern salamander conservation: (1) A system of land-use allocations
with associated Standards and Guidelines to guide land management; and,
(2) until recently, the Survey and Manage Mitigation Measure Standards
and Guidelines, which provided species-specific management guidance for
certain groups of species. The NWFP Record of Decision (ROD) was
implemented as amendments to all existing land and resource management
plans for the Bureau of Land Management (BLM) and USFS within the range
of the northern spotted owl.
Lands administered by the USFS and BLM are divided into five
primary categories of land management under the NWFP: Late-successional
Reserves, Congressionally Reserved Areas, Riparian Reserves, Adaptive
Management Areas, and Matrix. Late-successional Reserves are
established with an objective to protect and enhance conditions of
late-successional and old-growth forest ecosystems, which serve as
habitat for late-successional, forest-related species. Forest
management activities are highly restricted within Late-successional
Reserves. Congressionally Reserved Areas, such as Wilderness Areas,
Wild and Scenic Rivers, and National Monuments, are incorporated into
the design of the Late-successional Reserve System. Riparian Reserves
provide an area along all streams, wetlands, lakes, ponds, and unstable
areas where riparian-dependant resources receive primary management
emphasis. Maintenance of forested conditions in Riparian Reserves for
shading and water quality is also expected to contribute to dispersal
and breeding habitat for late-successional species. Adaptive Management
Areas (AMAs) are established to develop and test new management
approaches and timber harvest methods to integrate and achieve
ecological and economic health, and other social objectives. Matrix
lands consist of those Federal lands outside of the four other
categories described above. Production of timber and other commodities
is an important objective for Matrix lands. However, forests in the
Matrix also provide connectivity between Late-successional Reserves and
function as habitat for a variety of forest-dwelling species. The NWFP
Matrix Standards and Guidelines are designed to provide for important
ecological functions such as dispersal of organisms, carryover of some
species from one stand to the next, and maintenance of ecologically
valuable structural components such as logs, snags, and large trees.
The Matrix also provides ecological diversity by providing early-
successional habitat. Within Matrix, other land use allocations such as
Visual Emphasis Areas, Managed Wildlife Areas, and Retention Areas
carry additional restrictions on timber harvest and to some degree
function as reserves.
Table 3.--Federal Land Allocations Within the Estimated Ranges of the Siskiyou Mountains Salamander (SMS) and
Scott Bar Salamander (SBS)
----------------------------------------------------------------------------------------------------------------
Applegate Scott Bar SMS-SBS
SMS Grider SMS salamander complex
----------------------------------------------------------------------------------------------------------------
Total area in ac (ha)................................... 248,870 174,285 136,740 559,895
(100,712) (70,529) (55,335) (226,578)
[[Page 4389]]
Private Lands (%)....................................... 15 9 22 15
Federal Lands (%):
Reserves............................................ 33 73 51 50
Adaptive Management Area \1\........................ 42 0 0 19
Matrix-retention \2\................................ 1 13 19 9
Matrix-general forest \3\........................... 9 5 8 7
----------------------------------------------------------------------------------------------------------------
\1\ Experimental management to meet ecological, economic, and social goals.
\2\ Timber harvest restricted to accommodate various other management goals.
\3\ Timber production is a high priority.
Roughly 33 percent of the range of the Applegate salamander occurs
within reserves (Late-successional Reserves, Wilderness, Riparian
Reserves, and other land allocations withdrawn from scheduled timber
harvest), 42 percent of the range within the Applegate Adaptive
Management Area, 9 percent in Matrix, and 15 percent on private lands
(see Table 3 above). Nearly three-quarters of the range of the Grider
salamander is in reserves, and 18 percent is in Matrix; however, almost
three-fourths of the Matrix is in land-use allocations (retention
areas) where timber harvest is restricted (USDA 1994, pp. 4-73 to 4-
176). Fifty-one percent of the Scott Bar salamander's range is in
reserves, and an additional 19 percent occurs within retention areas
(Wild and Scenic Rivers, Retention Visual Quality Objective). Overall,
only approximately 14 percent of the range of the Applegate salamander,
24 percent of the range of the Grider salamander, and 30 percent of the
range of the Scott Bar salamander are composed of Matrix-General Forest
and private timberlands, where intensive timber management would be
expected to occur. However, because varying levels of timber management
occur within the Applegate Adaptive Management Area in the range of the
Applegate salamander, up to about 66 percent of this species' range is
available for various levels of timber harvest and cannot be considered
to be reserve lands.
Little is known about the actual distribution of salamander
populations among the land-use allocations described above. Nauman and
Olson (2007) attempted to evaluate the occurrence of Grider salamanders
and Scott Bar salamanders by conducting surveys at a stratified random
sample of points in reserved and matrix land allocations at high
(greater than 4,000 ft (1,219 m)) versus low (less than 4,000 ft (1,219
m)) elevation. They found that capture rates for these species were
higher on matrix lands, likely because a higher proportion of reserved
lands occur at higher elevations, which are less suitable for the
species. The authors concluded that reserved land allocations may not
provide adequately for conservation of the species but described a
number of sampling issues (single-visit protocol, unequal sampling of
strata) that may weaken this conclusion.
Survey and Manage Mitigation Measure Standards and Guidelines
In addition to the NWFP's system of land-use allocations and
management standards and guidelines, specific mitigation measures were
included for about 400 rare or poorly known species. We refer to this
broadly as the Survey and Manage Program. The Survey and Manage Program
contains an adaptive management provision, establishing the Species
Review Process wherein species experts (``taxa teams'') evaluate and
synthesize the latest information about each species. Reports from the
taxa teams are then used by the agencies to propose changes to
management of these taxa, as appropriate. The Siskiyou Mountains
salamander was included in the original list of Survey and Manage
species under Survey Strategies 1 and 2 (USDA and USDI 1994, pp. C-59,
C-45). Survey and Manage guidelines for these salamanders required that
known salamander sites be managed via protection buffers (Strategy 1),
and that surveys be conducted prior to ground-disturbing activities
such as timber harvest (Strategy 2). Protection buffer standards and
guidelines for Siskiyou Mountains salamanders required the retention of
all overstory trees within a buffer of at least the height of one site-
potential tree or 100 feet horizontal distance, whichever is greater,
surrounding the location. As a result of the 1999 Species Review
Process, the Siskiyou Mountains salamander was reclassified as a
Category C species in the Final Supplemental Environmental Impact
Statement (FSEIS) for the NWFP (USDA and USDI 2000, Appendix F; p.
101). Criteria for including a taxon in Category C are: (1) There is
not a high concern for persistence; (2) it is likely that not all known
sites are necessary for reasonable assurance of persistence of the
taxon; (3) the taxon is uncommon (as opposed to rare); and (4) pre-
disturbance surveys are required until a population network is
established. The management objective for the Siskiyou Mountains
salamander under Category C is to identify and manage high-priority
sites to provide for reasonable assurance of persistence. The current
status of the Siskiyou Mountains salamander was assigned in the March
14, 2003, Implementation of the 2002 Annual Species Review Memorandum
(USDA and USDI 2003). Because of their smaller number of known sites
and patchy distribution, salamander populations south of the Siskiyou
Crest were assigned to Category A, requiring pre-disturbance surveys
and management of protection buffers for all known sites. Northern
populations were assigned to Category D. Management objectives for
Category D species are to identify and manage high-priority sites to
provide for a reasonable assurance of species persistence; pre-
disturbance surveys are not required.
The USFS and BLM have determined to remove the Survey and Manage
Program, and in July 2007 published their Record of Decision (2007 ROD)
to implement this decision (see ``Summary of Factors Affecting the
Species: Factor D''). Therefore, at this time, the Survey and Manage
Program has been eliminated for project planning and new decisions.
However, because of the lag time in implementation of the 2007 ROD,
most new Federal land management decisions issued in 2008 will be
compliant with the Survey and Management guidance for the Siskiyou
Mountains salamander (West 2007); implementation of new projects
compliant with the 2007 ROD is unlikely until 2009. We therefore view
[[Page 4390]]
the Survey and Manage guidelines as existing habitat management until
after 2008. Unless the 2007 ROD is successfully challenged in court,
project decisions after 2008 will no longer contain protections
currently provided by the Survey and Manage provisions.
The Survey and Manage guidelines have provided additional security
for salamander populations across the vast majority of the range of the
Siskiyou Mountains salamander. With the removal of the Survey and
Manage Guidelines under the 2007 ROD, management of these species will
be based on the USFS's Special Status Species Program and the BLM's
Sensitive Species Program (Hughes 2007). The Special Status Species and
Sensitive Species programs are anticipated to provide less stringent
protections than those in the Survey and Manage Program; however, they
include provisions for development of Conservation Strategies and
Conservation Agreements.
Based on ecological and management information in the Annual
Species Reviews and strategic surveys, the taxa team joined with
additional species experts to formalize the Survey and Manage Program
objectives for Siskiyou Mountains salamander. In anticipation of the
eventual removal of the Survey and Manage Program, they developed their
management recommendations into a Conservation Strategy for Siskiyou
Mountains Salamanders in the Northern Portion of the Range (Olson et
al. 2007). The USFS and BLM committed to implement this Conservation
Strategy in the August 16, 2007, Conservation Agreement for the
Siskiyou Mountains Salamander (Plethodon stormi) in Jackson and
Josephine Counties of southwest Oregon and in Siskiyou County of
northern California (USDA and USDI 2007; USDI 2007b).
In accordance with management objectives for Category D species,
the Conservation Strategy relies on long-term management of a subset of
known salamander sites. A panel of scientists and resource managers
selected high-priority sites and considered a number of criteria
including existing Federal Standards and Guidelines for the planning
area, distribution and quality of habitat, known locations of
salamanders, and potential risk factors such as fire hazard, road
density, and land ownership. To ensure the existence of well-
distributed, interacting subpopulations, these criteria were evaluated
at three spatial scales: The entire Applegate River watershed, 19
smaller watersheds within the Applegate River watershed, and individual
sites. Of 316 known salamander locations on Federal lands, 151 (48
percent) were included in the 110 high-priority salamander management
areas selected (some management areas encompassed multiple salamander
sites). Of the 110 selected sites, 44 are on BLM lands and 66 are on
the Rogue River-Siskiyou National Forest. Each high-priority
salamander-management site is intended to maintain a subpopulation of
Siskiyou Mountains salamanders over the long term (100 years). Because
habitat-disturbing activities are regulated to varying degrees across
the entire NWFP area occupied by the salamanders, the scientists who
developed the strategy anticipate that many additional populations will
continue to persist in reserved lands and in Matrix where habitat is
retained for other reasons (Olson et al. 2007, p. 21).
Each high-priority salamander-management site was evaluated for
application of one of two management strategies. The first strategy
focuses on maintaining habitat conditions for salamanders at the site
by limiting activities that may have adverse effects on substrate,
ground cover, forest condition, or microhabitat and microclimate. The
second strategy allows for greater latitude in activities at the high-
priority site by applying the existing National Fire Plan Fire
Management Recommendations to the high-priority site. This two-tiered
approach attempts to integrate the fire ecology of the area, current
forest conditions, fuel loads, and proximity to populated areas while
providing for the persistence of Applegate salamander populations over
the long term.
The Conservation Strategy contains a rigorous risk assessment
(Olson et al. 2007, p. 22 and Appendix 2), which concludes that
implementation of the Strategy presents an extremely low risk to the
species' persistence at the range-wide scale. This conclusion is based
on evaluation of the comparative risk of losses of individuals or
subpopulations due to fuels management activities versus higher risk of
losses if high-intensity wildfires occur at untreated sites. Other
risks posed by other forest management activities are ameliorated by
the protection-buffer approach adopted from current Survey and Manage
guidance. Redundancy of protected sites and a mix of protective and
restoration approaches across the entire range of the Applegate
salamander also act to increase the likelihood of persistence over the
long term.
The Conservation Strategy was authored by four of the most
published scientific experts on this species (D. Olson, D. Clayton, H.
Welsh, and R. Nauman, among others), and incorporates habitat modeling
and risk assessment in the evaluation of species persistence and
distribution within the strategy area. The Conservation Strategy also
contains provisions to support monitoring and strategic surveys to
address gaps in our knowledge of the species and its conservation.
Funding for these efforts is anticipated to come from the USFS and
BLM's Special Status Species programs. Implementation and effectiveness
of this Conservation Strategy will be reviewed every five years by BLM,
USFS, and the Service. Based on these regular reviews, or significant
information that may become available between the five-year reviews,
the Conservation Strategy may be revised to refine the plan or address
emerging issues.
In anticipation of the discontinuation of the Survey and Manage
Program, biologists from the Klamath National Forest (KNF) and the
Service's Yreka Fish and Wildlife Office (YFWO) are developing a
Conservation Strategy to guide management of both Grider and Scott Bar
salamander populations on lands administered by the KNF. This Strategy
would apply to over 90 percent of the range of the Grider salamander
DPS, and 78 percent of the Scott Bar salamander's range. The draft KNF
Strategy does not require surveys to be conducted prior to ground-
disturbing activities; instead, all suitable salamander habitat (talus
substrate) is assumed to be occupied and managed for long-term
persistence of salamander populations. Similar to the Conservation
Strategy for Applegate salamanders (Olson et al. 2007), the draft KNF
Strategy balances protection of existing suitable habitat with active
management of risks such as hazardous fuels. Small habitat patches
(less than 5 ac (2 ha)) and locations with high likelihood of occupancy
by salamanders (lower slopes, northerly exposures) receive strict
protective guidelines; whereas habitat patches on upper slopes with
southerly exposures may receive fuels reduction treatments that reduce
canopy closure to a limited degree.
As discussed below in Factor D, we are not relying on
implementation of the Conservation Strategies in making our
determination that listing the Siskiyou Mountains salamander and Scott
Bar salamander is not warranted. We have included this discussion
solely as background for the public and to acknowledge USFS and BLM
efforts to
[[Page 4391]]
further reduce possible threats to the species.
Summary of Factors Affecting the Species
Section 4 of the Act (16 U.S.C. 1533) and implementing regulations
at 50 CFR part 424 set forth procedures for adding species to the
Federal List of Endangered and Threatened Wildlife. In making this
finding, we summarize below, information regarding the status and
threats to this species in relation to the five factors in section
4(a)(1) of the Act. In making our 12-month finding, we considered and
evaluated all scientific and commercial information in our files,
including information received during the public-comment period that
ended May 29, 2007.
Siskiyou Mountains Salamander
Factor A: The Present or Threatened Destruction, Modification, or
Curtailment of the Species' Habitat or Range
Like other plethodontids, Siskiyou Mountains salamanders require
moisture for respiration (Nussbaum et al. 1983, pp. 73, and 90). This
physiological requirement limits the time during which they are active
at the soil's surface to relatively brief, rainy periods in the spring
and fall (Nussbaum et al. 1983, pp. 102-103; Clayton et al. 1999, p.
133). These salamanders engage in important behaviors, including
foraging and breeding, during periods of surface activity (Feder 1983,
p. 296). During the remainder of the year, they retreat into rocky
substrates, which provide refuge from the climatic extremes of the
eastern Klamath Mountains (Nussbaum et al. 1983, p. 102). Given their
physiology and life histories, disturbances that reduce surface and
soil moisture, relative humidity, or suitable rocky substrates may
negatively affect these species. Disturbances that possibly impact
Siskiyou Mountains salamanders include timber harvesting, fires, road
construction, mining, and quarrying.
Effects of Timber Harvesting on Siskiyou Mountains Salamanders
Timber harvesting may impact Siskiyou Mountains salamander by
killing individuals or by reducing habitat quality. Ollivier et al.
(2001, pp. 41-42) and Welsh et al. (2007a, p. 28) found that Siskiyou
Mountains salamanders were associated with characteristics found in
mature forests, such as dense canopy cover, large-diameter trees, and
mossy ground cover. Other studies have shown that Siskiyou Mountains
salamanders occur within a wide range of forest conditions, including
in recently clear-cut sites and in open-canopy forest (e.g., Bull et
al. 2006, p. 24; Farber et al. 2001, p. 13; Farber 2007, p. 3). The
conclusions of these studies do not necessarily conflict since it is
possible that these salamanders occur within a wide range of habitat
conditions while selectively using or receiving greater fitness from a
subset of them, or are more easily detected in a subset of them.
Alternatively, these species may select habitat based on attributes
that are not dependent on forest age or structural class. For example,
they may select habitat with cool, moist microclimates, which are
common in mature forests but also occur under other conditions (e.g.,
in deep drainages or on north-facing slopes). The paucity of rigorous
scientific information about Siskiyou Mountains salamanders makes an
accurate evaluation of their habitat associations (see Habitat
Associations section above) and sensitivities to timber harvesting
difficult. Information about the effects of timber harvesting on this
species is currently limited to inferences based on the physiology of
this species, two studies of the effects of timber harvesting on
Siskiyou Mountains salamanders, and extrapolation of inferences from
studies of the effects of timber harvesting on other species of
plethodontid salamanders.
Timber harvesting may negatively affect Siskiyou Mountains
salamander by reducing soil moisture and increasing soil temperature.
Studies by Chen et al. (1993, pp. 233-234; 1995, pp. 77-82; 1999, pp.
292-294) in Pacific Northwest Douglas fir forests found that both soil
and air were drier and warmer in clear cuts and clear-cut forest edges
than in adjacent old-growth forest. These results indirectly suggest
that clear-cutting may negatively affect these animals. We are not
aware of any studies on the effects of other silvicultural techniques
on forest microclimates. However, alternative even-age harvesting
techniques (shelterwood and seed-tree cuts), uneven-age harvesting
(single tree and group selection harvesting), and thinning retain more
canopy cover than does clear-cutting and, therefore, probably have
lower impacts on forest microclimates. The effects of timber harvesting
also strongly depend on the silvicultural prescription (e.g., the
volume of wood removed and the size, volume, and distribution of
retained trees, snags, and logs) and on site-specific factors (e.g.,
climate and slope aspect). We expect that the effects of silviculture
on Siskiyou Mountains salamander depend primarily on the intensity and
scale of the disturbance.
We are aware of two studies analyzing the effects of timber
harvesting on Siskiyou Mountain salamanders. The first was conducted in
Siskiyou County, California by the USFS (D. Clayton, cited in Bull et
al. 2006, p. 21; Olson et al. 2007, p. 16). This study compared
abundances of Siskiyou Mountains salamanders through time at a clear-
cut site and an adjacent selectively cut site. In the clear-cut site,
the researchers found 40 salamanders (10 salamanders per person, per
hour) the spring after the harvest, one juvenile the following year, no
animals in the subsequent 7 years, and one juvenile during an
opportunistic survey in the tenth year. In comparison, they
consistently found 3 to 6 salamanders per person, per hour in the
selectively cut site during the same years sampled (Bull et al. 2006,
p. 21). The CDFG resurveyed the same clear-cut site in the spring and
fall of the eleventh year post-harvest (Bull et al. 2006, p. 21).
Single surveyors found 10.6 salamanders per person, per hour in the
spring and 4.25 salamanders per person, per hour in the fall. This
result suggests that, while Siskiyou Mountains salamanders may be
negatively impacted by intensive timber management practices such as
clear-cutting, they are able to recover in, or recolonize, some clear-
cuts as vegetation recovers. As importantly, less intensive harvest
methods may have less impact on salamander abundance. However,
inferences from both sets of surveys are highly limited because the
surveys did not include pre-harvest data and were conducted in only one
pair of plots.
In a nearby area, Fruit Growers Supply Company monitored Siskiyou
Mountains salamanders on the Elliot Fly Timber Harvesting Plan. They
monitored salamanders on 39 plots (35 harvested and 4 controls). The
harvesting method was a selective cut, and logs were removed by
helicopter, a method which significantly reduces the amount of ground
disturbance. Plots were surveyed prior to harvest, 1 year post-harvest,
and 10 years post-harvest (Taylor 2007, p. 1). Estimates of relative
abundance (count data) in the harvested plots ranged from 1.8 to 2.0
captures per survey compared to 2.0 to 3.2 captures per survey in
unharvested controls, and did not significantly change during the
study. These results suggest that the harvest did not significantly
adversely affect the salamanders (Taylor 2007, p. 3). The determination
of no significant difference between treatments and control plots was
likely influenced by the high variability observed within and
[[Page 4392]]
between plots. All Siskiyou Mountains salamander life stages were found
in the harvested plots, likely indicating that these populations
continued to reproduce following harvesting. Although this study used a
more rigorous design and was larger than the nearby USFS paired-plot
study, its inferences are also limited because pre-harvest data were
only collected one year prior to harvest and the study plots were not
randomly selected.
All life-history stages of Siskiyou Mountains salamander, including
gravid females (carrying eggs), have been found in open-canopy forest
and recent clear-cuts (Farber et al. 2001, p. 13; Bull et al. 2006, p.
24; Farber 2007, p. 3). However, little is known about relationships
between forest conditions and the population dynamics of the Siskiyou
Mountains salamander. Welsh et al. (2007b) analyzed relationships
between forest age class and the age structure and body condition of
both Siskiyou Mountains salamanders and Scott Bar salamanders. All
salamander age classes were found in pre-canopy (0 to 33 years) sites,
but 8 of 11 individuals detected in those sites were juveniles or
subadults. If representative of population age structure, this
observation could indicate that pre-canopy sites function as `sink' or
dispersal habitat for non-reproductive individuals. Alternatively, high
proportions of juveniles could indicate high reproductive rates and
population recovery following logging. Sample sizes were too small to
test these hypotheses. Welsh et al. (2007b) also found that Siskiyou
Mountains salamanders in mature (100 to 199 years) sites had
significantly higher median body condition (ratio of body mass to
length) than those in young sites (31 to 99 years). This could indicate
that young forest stands provide lower quality habitat than mature
stands.
Timber harvesting could also affect Siskiyou Mountains salamanders
at spatial scales larger than individual salamander sites. The petition
to list the Siskiyou Mountains salamander (Center for Biological
Diversity et al. 2004, p. 8) asserts that timber harvesting creates
gaps in the distribution of this species because it is rarely able to
recolonize habitat after local populations are extirpated. Indirectly
supporting this hypothesis, studies of the closely related Del Norte
salamander showed that it is highly sedentary and, therefore, likely to
have limited dispersal abilities. Welsh and Lind (1992, p. 427)
reported that the longest movement by an individual Del Norte
salamander was 119 ft (36.2 m) over 6 months, and Lowe (2001, p. 27)
found that the longest movement was 129.9 ft (39.6 m) over 2 years.
Average movements were substantially smaller than these: 22 ft (6.7 m)
over 2 years (Lowe 2001, p. 27) and 16.7 ft (5.1 m) over 6 months
(Karraker and Welsh 2006, p. 136). Siskiyou Mountains salamanders, and
in particular Scott Bar salamanders, have relatively longer limbs than
Del Norte salamanders and may be capable of longer movements, but their
dispersal abilities are still likely limited. Some researchers have
suggested that dispersing juvenile Siskiyou Mountains salamanders
readily colonize logged sites (Welsh 2005, pp. 1-2) and road cutbanks
(Nussbaum 1974, p. 13). Alternatively, it is possible that salamanders
in regenerating logged sites and road cutbanks are indicative of
population persistence and recovery following disturbance, rather than
extirpation and subsequent recolonization.
Welsh and Ollivier (1995, pp. 8-9) suggested that tractor yarding
of logs during timber harvesting may impact Siskiyou Mountains
salamanders by compacting, breaking, or realigning talus. If tractor
yarding has these effects, it could reduce the interstitial spaces in
talus and thereby reduce habitat quality for these species. Although it
is reasonable to conclude that tractor yarding may disturb talus
substrates, research has not demonstrated how this affects salamander
populations.
In summary, rigorous research of the effects of timber harvesting
on Siskiyou Mountains salamanders is needed, but intensive timber
harvesting practices, such as clear-cutting and tractor yarding, appear
to have negative short-term (30 years or less) effects on abundance,
population structure, and body condition of these species (Welsh et al.
2007b). Intensive timber harvesting likely affects these salamanders by
changing forest characteristics that influence microclimates for them,
for example, by opening the forest overstory and understory canopies
and reducing coverage of down wood and leaf litter. Despite these
effects, it is also clear that the salamanders frequently persist in
intensively harvested habitats, and there is no information suggesting
that populations are permanently extirpated by timber harvest. It is
unknown whether these salamanders may be temporarily extirpated from
severely disturbed sites or simply retreat underground during the
initial period of post-disturbance recovery. Alternative silvicultural
techniques, such as thinning, selective harvesting, and helicopter
yarding, appear to be less harmful to these salamanders than more
intensive harvesting methods.
Timber Harvesting Effects on Other Plethodontids
To support their assertion that the Siskiyou Mountains salamander
is threatened by timber harvesting, the petitioners cite studies of
other closely related species. Most studies of the closely related Del
Norte salamander indicate that this salamander is more abundant in
mature forest than in other forest age classes (Raphael 1988, p. 27;
Welsh and Lind 1991, p. 400; Welsh and Lind 1995, p. 208). In contrast,
Diller and Wallace (1994, p. 316) did not detect a relationship between
forest age and the presence of Del Norte salamanders near the northern
California coast. It is possible that forest structural characteristics
(e.g., canopy cover) more strongly influence microclimates for
salamanders in the interior of the Klamath Mountains than near the
coast, where temperatures are more moderate and moisture is less
limiting.
Karraker and Welsh (2006, p. 137) found lower abundances of Del
Norte salamanders in clear-cuts than in mature stands. All salamander
life stages were observed in clear-cuts, indicating that reproduction
was occurring in them. Abundances were similar in commercially thinned
and mature stands. Welsh et al. (2007b) found significant positive
relationships between forest age class and presence and abundance of
Del Norte salamanders. Adult salamanders accounted for a larger
proportion of individuals observed in old-growth (older than 200 years)
and mature (100 to 199 years) stands than they did in young (31 to 99
years) stands. The authors suggested that higher proportions of adult
salamanders are indicative of greater population stability for this
species. In contrast, salamanders at pre-canopy (0 to 33 years), young,
and old-growth sites had higher median body condition than those in
mature stands or the reference site (thought to be a high-quality
site). The authors speculated that the apparent inconsistencies in
their results were related to greater competition and poorer body
condition in sites with higher salamander abundances, but more research
is needed to test this hypothesis. Biek et al. (2002, p. 137) found
similar abundances of Del Norte salamanders in clear-cuts and mature
forests in Oregon, apparently contradicting the results of the studies
discussed above.
Evaluation of studies of the effects of timber harvesting on
plethodontids outside the Plethodon elongatus Complex may improve our
[[Page 4393]]
understanding of the effects of harvesting on Siskiyou Mountains
salamanders. However, these studies should be cautiously considered due
to differences in the natural histories of these species. Most
plethodontids occupy soil, surface litter, and woody debris in mesic
environments (e.g., where it frequently rains during summer), whereas
Siskiyou Mountains salamanders occupy talus substrates, which provide
refuge from the temperature extremes and dry conditions that
characterize the eastern Klamath Mountains.
Grialou et al. (2000, pp. 108-110) found that western red-backed
salamanders in mesic forests in southwestern Washington occupied recent
clear-cuts (2 to 4 years post-harvest) but at significantly lower
abundances than in adjacent older stands. Body sizes of salamanders
(subadults and juveniles) were smaller the year after harvesting but
were normal by the second year. Gravid females were captured on clear-
cut plots before and after harvest. Grialou et al. (2000, p. 111)
suggested that reduced abundances of western red-backed salamanders in
clear-cuts were related to soil compaction, loss of woody debris, and
decreased leaf litter cover associated with harvesting. Bury and Corn
(1988, p. 171) reported plethodontid salamanders to be absent in four
clear-cut study sites, but their results were equivocal because
detection rates were very low in all of the habitats studied. In
contrast to the above studies, Corn and Bury (1991, p. 311) found that
abundances of western red-backed salamanders were not significantly
different in recent clear-cuts (less than 10 years old) and old-growth
forest.
Studies of plethodontids in the mid-western and eastern United
States (Ash 1997, p. 985; deMaynadier and Hunter 1998, pp. 344-345;
Herbeck and Larsen 1999, p. 626) and western Canada (Dupuis et al.
1995, p. 648) indicated that clear-cutting can have significant short-
term impacts on plethodontid salamander abundance. Dupuis et al. (1995,
p. 648), Ash (1997, p. 987), and Herbeck and Larsen (1999, p. 626)
reported that plethodontid salamanders were frequently absent from 2-
to 5-year-old clear-cut stands. However, the impact of clear-cutting on
these salamanders may be temporary, as one study (Ash 1997, pp. 985-
986) showed that salamanders returned to clear-cut areas 4 to 6 years
after cutting, and their return was followed by rapid increases in
their numbers. Statistical modeling of salamander abundances on clear-
cut plots indicated that salamanders would equal or exceed numbers on
forested plots by 20 to 24 years after cutting (Ash 1997, pp. 985-986).
Knapp et al. (2003, pp. 754-758) used a randomized, replicated design
to quantify plethodontid salamander populations on harvested
timberlands of the Appalachian Mountains in Virginia and West Virginia.
While salamander abundances were lower in clear-cuts than in control
plots, there were no differences in the proportion of gravid females or
in the average number of eggs in gravid females. Moreover, there were
no differences in the proportion of juvenile animals, except in one
plethodontid species, which had a higher proportion of juveniles in
uncut treatments.
Extent of Timber Harvesting Within the Range of the Siskiyou Mountains
Salamander
Evaluation of the threat potentially posed by modification or loss
of habitat via timber harvest must be based on an assessment of the
biological mechanisms involved, as well as quantification of the
likelihood of those mechanisms occurring to an extent and magnitude
reasonably expected to result in the threat of extinction. The extent
and magnitude of potential effects caused by timber harvest are
strongly influenced by existing land management regulations on the
majority of the species' ranges. Approximately 85 percent of the range
of the Siskiyou Mountains salamander occurs on Federal lands managed
under the NWFP (USDA and USDI 1994) (see Table 3 above). In general the
system of reserves and management guidelines provided by the NWFP
provide a substantial reduction in the likelihood of widespread habitat
alteration due to timber harvesting.
The rate and extent of timber harvest has declined dramatically on
Federal lands within the NWFP area during the past 30 years (USDA and
USDI 2005), particularly on the Klamath National Forest, which
comprises roughly 91 percent of the range of the Grider salamander.
These reductions have been primarily due to the implementation of the
NWFP and other Federal land management regulations. During the 6-year
period from 2000 to 2005, the Klamath National Forest sold and removed
an average of 15.9 million board feet of timber annually, compared with
187.8 million board feet per year during 1985 to 1990 (inclusive), and
238.2 million board feet per year from 1979 to 1984; this marks a
reduction of roughly 93 percent from the 1979 to 1984 period (USDA
2006a). Perhaps more importantly, the amount of intensive timber
management (regeneration harvests, overstory removal) has declined
sharply, from an average of 3,733 ac per year from 1988 to 1991, to 38
ac per year from 2000 to 2006. Intensive harvest prescriptions such as
clear-cutting were not used in 2001 or 2002, nor in 2004 to 2006 (USDA
2007b). Likewise, timber harvest on the Rogue River National Forest
(which comprises roughly 66 percent of the range of the Applegate
Population of the Siskiyou Mountains salamander (Clayton 2007b)
declined by 96 percent during the last 30 years. Annual timber harvest
during the 1980s averaged 182 million board feet, compared with 8
million board feet per year from 2000 to 2006 (USDA 2007c). Since 1996,
only one timber sale has been sold and harvested on the Rogue River
National Forest's Applegate Ranger District. Timber harvest,
particularly intensive harvest methods, has also declined dramatically
on lands administered by the BLM within the range of Applegate
salamander. Mean annual harvest on the BLM's Ashland Resource Area have
declined from 2,240 ac (907 ha) per year between 1995 and 2000, to 664
ac (269 ha) per year between 2001 and 2007 (USDI 2007a). Less than 270
ac (109 ha) per year have been harvested since 2003 (USDI 2007a).
Intensive harvest methods, such as clear-cuts and shelterwood harvests,
have declined from 54 percent of acres harvested in the mid-1990s, to
less than 1 percent of the annual harvest since 2001. The
implementation of the NWFP and subsequent declines in timber harvest
levels on Federal lands, particularly intensive harvests thought to
potentially affect salamanders, greatly reduces the likelihood that a
substantial proportion of the salamanders' populations will be affected
by logging. We anticipate that reduced levels of timber harvest will
continue into the foreseeable future because this has been the trend
for the last 30 years and we have no substantial information that
indicates that this trend will be reversed in the foreseeable future.
In addition, the essential goals of the NWFP remain in effect and we
have no information that would lead us to anticipate changes to the
overall goals of this ecosystem management strategy. The removal of the
Survey and Manage guidelines is relevant only to occupied salamander
sites that overlap with Federal forest management projects; this
comprises a very small fraction of the NWFP area and will have an
insignificant effect on the overall levels of timber harvest within the
range of the Siskiyou Mountains salamander.
[[Page 4394]]
Intensive timber harvest methods such as clear-cutting are
extremely limited in extent on Federal lands within the ranges of these
salamanders, but where they occur they may reasonably be expected to
have negative impacts on salamander populations. The available evidence
does not demonstrate that the less-intensive harvest methods commonly
employed on Federal lands have had substantial impacts to salamander
populations, and we do not anticipate such impacts in the future.
However, we acknowledge that the relationship between degree of
management intensity and effects to salamanders requires further
investigation.
Intensive timber harvesting practices on private timberlands affect
only 10 percent of the Siskiyou Mountains salamander's range. The
majority of private lands within the salamander's range occur as small
parcels (typically one square mile or less) in a checkerboard pattern
surrounded by Federal lands. Salamander populations on private lands
may be negatively affected by timber harvesting but are dispersed among
populations on Federal lands where management is more favorable. This
acts to maintain redundancy, distribution, and connectivity among
Siskiyou Mountains salamander populations within the mix of Federal and
private lands. In addition, surveys and monitoring of Siskiyou
Mountains salamanders on private timberlands demonstrate that numerous
populations of Siskiyou Mountains salamanders continue to exist post-
harvest and some exhibit evidence of normal population structure
(Farber et al. 2001, p. 13; Bull et al. 2006, p. 24; Farber 2007, p.
3), indicating that extirpation of salamander populations on harvested
private timberlands is not a substantial threat to the species.
Wildfire
Wildfire is thought to be a potential threat to Siskiyou Mountains
salamander habitat (Olson et al. 2007, pp. 15, 25-26). Fire suppression
and logging have altered forest structure and increased fuel loading in
much of the Klamath-Siskiyou region (Skinner et al. 2006, pp. 178-179).
Fire regimes within the ranges of the species have largely shifted from
frequent, low-to-moderate or mixed-severity fires to less frequent,
more severe fires (Agee 1993, pp. 388-389; Taylor and Skinner 1998, p.
298; USDA 1999, pp. 2-76 and 2-82; Skinner et al. 2006, p. 191).
However, debate exists concerning the extent to which this effect is
operating in the Klamath and Siskiyou Mountains (Odion et al. 2004, pp.
933-934). Climate changes associated with global warming are expected
to increase the frequency of large, severe fires in this region (see
Factor E discussion below). However, fire modeling suggests that the
level of tree mortality would be highly variable within the geographic
ranges of these species (USDA 1999, pp. 2-76 and 2-82; Suzuki and Olson
2007, p. 8), resulting in a mosaic pattern of habitat effects. Similar
mosaics of effects have been documented for large fires in other
regions (e.g., Eberhart and Woodard 1987, pp. 1207-1212). In addition,
the talus outcrops inhabited by these salamanders may modify the
behavior of fire (e.g., Major 2005, p. 95) by acting as minor fuel
breaks and influencing the mosaic of burned and unburned areas.
The direct effects of fire on these species are unknown but
interstitial spaces in deeper talus habitat likely provide underground
refugia for these salamanders during fires (DeGross and Bury 2007, p.
7). In addition, wildfires typically burn during the dry summer and
fall months when the salamanders are not on the surface; the period of
surface activity coincides with wet climatic conditions prohibitive to
wildfire.
The indirect effects of fire on these species are also unknown.
Severe wildfires, by definition, remove or significantly reduce canopy
cover; consume moss, duff, and forest litter; and may sterilize surface
soil layers. Siskiyou Mountains salamanders occasionally use woody
debris as cover during surface activity, and canopy and leaf litter
cover may influence habitat quality for them (see Habitat Associations
section), so these habitat changes likely affect salamanders during
some period of post-fire recovery.
We are unaware of any studies of the effects of prescribed burning
on Siskiyou Mountains salamanders. Prescribed fires are usually applied
in the spring or fall, when moisture levels minimize the risk of damage
to mature trees and unacceptable spreading of fire. Moisture levels
during periods of surface activity by these species are higher than
those that are appropriate for prescribed burning, so the risk of
direct mortality during prescribed fires is likely low. Prescribed
fires could temporarily reduce the quality of habitat for these species
by consuming understory vegetation, down wood, litter, and duff.
Conversely, the benefits of prescribed fires may outweigh their costs
to salamanders in some areas by reducing the risk of severe wildfires.
Roads and Road Construction
Research suggests that forest roads may significantly restrict
movements and local abundances of plethodontid salamanders (deMaynadier
and Hunter 2000, pp. 63-64; Marsh et al. 2005, p. 2006; Semlitsch et
al. 2007, p. 159). Forest roads may reduce dispersal by salamanders,
leading to lower gene flow and reduced long-term persistence of
populations (Marsh et al. 2005, p. 2007). Conversely, Nussbaum (1974,
p. 13) found numerous salamander locations within road cuts, and
suggested that the road construction provided habitat in the form of
newly exposed fissured rock, or at least did not render the adjacent
habitat unsuitable. Within the ranges of the Siskiyou Mountains
salamander, roads are typically constructed for access to timber
harvest operations. While road densities are high in some areas within
the ranges of the salamanders (USDA 1999, pp. 2-31), the amount of road
construction activity has declined sharply as timber harvest levels
have dropped. Road decommissioning projects may have short-term
localized effects to rock substrates, but are designed to re-create a
natural substrate. The small area affected by road construction and the
linear nature of habitat impacts, combined with the ability of
salamander populations to occupy road cuts, suggest that forest roads
do not pose a significant threat to populations of Siskiyou Mountains
salamanders (Olson et al. 2007, p. 17). We are not aware of any other
information that suggests that the presence of roads or road
construction presents a substantial threat to the Siskiyou Mountains
salamander.
Mining and Rock Quarrying
Some sites occupied by the Siskiyou Mountains salamander have
evidence of previous mining activity. It is unclear whether or how
salamanders in those sites may have been affected by these activities.
Rock quarrying could pose a greater threat to individual populations
because of the potentially greater intensity of the disturbance.
However, this activity occurs within an extremely small proportion of
this species' range, and is unlikely to have more than localized
effects (Olson et al. 2007, p. 17). We are not aware of any information
that suggests that mining or rock quarrying presents a substantial
threat to the Siskiyou Mountains salamander.
Summary of Factor A
While intensive timber management practices such as clear-cutting
appear to
[[Page 4395]]
have negative impacts on the abundance of Siskiyou Mountains
salamanders, this practice is severely restricted on Federal lands that
constitute the vast majority of the species' range. Less intensive
harvest practices appear to have relatively minor or short-term impacts
to salamander abundance, and the available evidence suggests that
salamander populations persist in a broad range of forest habitat
conditions and under different management practices.
Current management on Federal lands under the provisions of the
NWFP protects salamanders via a system of reserves and land management
guidelines (see Background Information: Land Management) that
dramatically reduce the likelihood of large-scale reduction of suitable
or occupied habitat. Until recently, the Survey and Manage guidelines
also served to protect occupied salamander sites from disturbance from
management activities. In the northern portion of the range, a
Conservation Strategy has been implemented that will essentially
continue the Survey and Manage Protections for Applegate salamander.
However, even without Survey and Manage or Conservation Strategy
protections, the available evidence does not show that timber harvest
practices on Federal lands, either alone or in combination with other
habitat disturbing activities such as mining, road building or
wildfire, have substantially reduced the habitat or range of this
species or are likely to do so in the foreseeable future.
Intensive timber harvesting practices, such as clear-cutting and
shelterwood removal, are more likely to occur on private timberlands.
While it is reasonable to assume that abundance and population
structure of Siskiyou Mountains salamander populations on private
timberlands may be negatively affected by timber harvesting and other
habitat disturbances, these lands constitute less than 10 percent of
the species' range. Other factors combine to greatly reduce the
likelihood that Siskiyou Mountains salamander populations will be
threatened by management activities on private lands: (1) The majority
of private lands within the species' range occur as small parcels
(typically one square mile or less) in a checkerboard pattern
surrounded by Federal lands; and (2) many salamander populations have
persisted on private timberlands in spite of a history of timber
harvest. We, therefore, conclude that timber harvesting and other
management practices on private lands do not constitute a substantial
threat to the Siskiyou Mountains salamander.
Wildfires are expected to occur and may reduce habitat quality for
some salamander populations; however, the effects of wildfires on
salamander habitat are temporary and populations appear to recover as
vegetation recovers. Wildfires typically burn in a mosaic pattern of
intensities, leaving a variety of habitat conditions for salamanders
within burned areas.
In summary:
(1) There is no evidence that the range of the Siskiyou Mountains
salamander has changed from its historical size.
(2) Despite over a century of mining, road building, and intensive
timber harvest, salamander populations remain well-distributed in a
wide variety of habitat conditions.
(3) Results of field studies and surveys indicate that salamander
populations recover following intensive habitat disturbances.
(4) On Federal lands, which constitute the majority of this
species' range, NWFP land allocations and Standards and Guidelines
(excepting the Survey and Manage program) and other regulations
contained in Land and Resource Management Plans provide a broad range
of protections for salamander habitat.
(5) The rate and intensity of timber harvest has declined
dramatically on Federal lands and there is no reliable information
suggesting that harvest rates or intensity will increase substantially
in the foreseeable future.
(6) While more intense harvesting may occur on private lands, these
lands are patchily distributed among Federal land holdings and taken
together constitute less than 10 percent of the species' range.
(7) Available evidence does not indicate that other potential
habitat threats to salamanders, individually or in combination with
timber harvest (i.e., wildfire, mining and rock quarrying, and road
building) have resulted in, or are likely in the foreseeable future to
result in, significant habitat loss that would pose a threat to
salamanders.
Therefore, we conclude that the Siskiyou Mountains salamander is
not now or in the foreseeable future, threatened by destruction,
modification, or curtailment of its habitat or range.
Factor B: Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
We are not aware of any information that indicates overutilization
for commercial, recreational, scientific, or educational purposes
threatens now, or in the foreseeable future, the Siskiyou Mountains
salamander across its range.
Factor C: Disease or Predation
Chytridiomycosis is a relatively recently described epidermal
infection of amphibians caused by the chytrid fungus Batrachochytrium
dendrobatidis. Chytridiomycosis has been implicated in mass
mortalities, population declines, and extinctions of some amphibian
species, but species appear to vary in their susceptibility to the
disease (Daszak et al. 1999; Blaustein et al. 2005; Ouellet et al.
2005; Pearl et al. 2007). This disease is most likely transmitted to
amphibians by contact with infected water or other amphibians (Johnson
and Speare 2003, p. 922). Batrachochytrium dendrobatidis requires
moisture for survival (Johnson and Speare 2003, p. 922) and is
therefore more likely to pose a threat to aquatic amphibians than to
terrestrial ones. However, a chytrid infection was recently found in a
terrestrial salamander, the Jemez Mountains salamander (Plethodon
neomexicanus), living in a wet meadow (Cummer et al. 2005, p. 248).
Infected aquatic amphibians appeared to be the most likely source of
transmission of the disease to this individual. Bullfrogs (Rana
catesbeiana) infected with B. dendrobatidis were recently found in a
pond in Trinity County, California (Bettaso and Rachwicz 2006, p. 162),
so it is possible that the disease occurs, or will soon occur, within
the range of the Siskiyou Mountains salamander. Nonetheless, we do not
anticipate that the Siskiyou Mountains salamander will be exposed to
this disease or that exposure would lead to transmission through a
significant portion of its range. This species is not associated with
bodies of water, occurs in a characteristically dry environment, is
only active above ground for brief and intermittent periods during the
year, and appears to have limited dispersal abilities. Given these
restrictions, we believe that the Siskiyou Mountains salamander is
unlikely to be exposed to diseased water or infected aquatic amphibians
and, if infected, is unlikely to transmit the disease between
populations.
The Service is not aware of any predators that potentially pose a
threat to the species.
Therefore, we find disease or predation does not threaten now, or
in the foreseeable future, the Siskiyou Mountains salamander across its
range.
Factor D: Inadequacy of Existing Regulatory Mechanisms
To the extent that we identify possibly significant threats in the
other factors, we consider under this factor
[[Page 4396]]
whether those threats are adequately addressed by existing regulatory
mechanisms. Thus, if a threat is minor, listing may not be warranted
even if existing regulatory mechanisms provide little or no protection
to counter the threat.
As described above in the ``Background: Land Management'' section,
habitats occupied by Siskiyou Mountains salamanders receive protection
from a number of sources such as the NWFP and other Federal land
management regulations. Until recently, protections for the Siskiyou
Mountains salamander on Federal lands included the Survey and Manage
Mitigation Measure Standards and Guidelines portion of the NWFP. On
private lands in California, the species complex receives protection
pursuant to the California Endangered Species Act (CESA). The future of
some of these regulations (Survey and Manage Program and State
Protections) is in flux.
Federal Lands
Survey and Manage Mitigation Measure Standards and Guidelines
Siskiyou Mountains salamanders and their habitat have received an
additional layer of security from the Survey and Manage Mitigation
Measure Standards and Guidelines (Survey and Manage Program) under the
NWFP (USDA and USDI 1994). The Survey and Manage Program provided
specific guidance for management of both genetic subunits of the
Siskiyou Mountains salamander. Management guidance for Applegate
salamander populations included identification of high-priority sites
that will be managed to provide a reasonable assurance of long-term
species persistence. In the southern portion of the range (Grider and
Scott Bar salamanders), protections included the requirement of surveys
prior to land management activities, and restrictions of habitat-
altering activities such as timber harvesting at occupied sites (see
``Background: Land Management''). The USFS and BLM decided to remove
the Survey and Manage Program from the NWFP, and published their ROD
entitled ``To Remove or Modify the Survey and Manage Mitigation
Measures Standards and Guidelines in Forest Service and Bureau of Land
Management Planning Documents Within the Range of the Northern Spotted
Owl'' in March 2004 (March 2004 ROD). The FSEIS for the March 2004 ROD
identified potential mitigation measures, including sensitive species
programs, for species affected by the removal of the Survey and Manage
Program.
In January 2006, the court in Northwest Ecosystem Alliance v. Rey,
2006 U.S. Dist. Lexis 1846 (N.D. Wash.) ordered the March 2004 ROD set
aside for failure to comply with the National Environmental Policy Act.
With this order, the court reinstated the 2001 Survey and Manage ROD,
which had modified the original Survey and Manage Program but
maintained protections for the salamanders. At the end of July 2007,
the USFS and BLM issued a new ROD (2007 ROD) to remove the Survey and
Manage Mitigation Measure Standards and Guidelines portion of the
Northwest Forest Plan. Following issuance of the 2007 ROD, the USFS and
BLM petitioned the court to lift or modify the injunction against
projects that relied on the 2004 ROD. In its November 21, 2007, order,
the court denied the agencies' request (Conservation Northwest v. Mark
E. Rey 2007 U. S. Dist. Lexis 88541 (N. D. Wash.)), but did not rule on
the sufficiency of the 2007 ROD.
With issuance of the 2007 ROD, the Survey and Manage Program has
been eliminated for new project planning and decisions. However,
because of the lag time in implementation of the 2007 ROD, most new
Federal land management decisions issued in 2008 will be compliant with
the former Survey and Management guidance for the Siskiyou Mountains
salamander (West 2007); implementation of new projects compliant with
the 2007 ROD is unlikely until 2009. Although judicial challenge to the
removal of the Survey and Manage Program in the 2007 ROD is very
likely, we assume for purposes of this finding that the Survey and
Manage Program will not remain in effect in the future.
Assuming the removal of the Survey and Manage Program, management
of this species will be based on the USFS's Special Status Species
Program and the BLM's Sensitive Species Program (Hughes 2007). The
Special Status Species and Sensitive Species programs are anticipated
to provide less stringent protections than those in the Survey and
Manage Program; however, they include provisions for development of
conservation strategies and Conservation Agreements, which, as
discussed previously under ``Land Management,'' has already occurred
with regard to the Applegate salamander, and is under development for
the Grider salamander and Scott Bar salamander.
It is important to note that, while the Service recognizes the
added layer of security provided by Survey and Manage Protections for
the Siskiyou Mountains salamander, our evaluation of the potential
threats to this species does not indicate that the Survey and Manage
Protections are key to the species' persistence. The petitioners cite
statements in the 2004 FSEIS (USDA and USDI 2004) indicating that loss
of the Survey and Manage Protections could result in gaps in the
distribution of Siskiyou Mountains salamander. In addition, the Species
Review Panel (USDA and USDI 2001, p. 16) concluded that ``[i]t is
likely that non-protected land allocations will be required in order to
ensure persistence for the species, both in the northern and southern
portions of the range'' indicating that current reserves may be
inadequate. We have carefully evaluated this information, and we find
that these conclusions are no longer consistent with the current
scientific knowledge about the Siskiyou Mountains salamander and Scott
Bar salamander, because: (1) The conclusions were made based on a much
smaller number of known populations (161) than what is known today
(631); (2) they are based on a single unpublished habitat-associations
study by Ollivier et al. (2001); and (3) they assumed extirpation of
populations that experience any degree of timber harvesting. As
described previously under ``Summary of Factors Affecting the Species:
Factor A,'' the best available evidence indicates that Siskiyou
salamanders persist in areas affected by timber harvest, and in
particular, in areas subject to the less intensive harvesting methods
employed on the vast majority of Federal lands that make up the species
range and there is little evidence to support the speculation that the
rate and intensity of timber harvest on Federal lands will increase in
the foreseeable future, with or without the Survey and Manage
protections.
Conservation Strategies
Conservation Strategy for the Siskiyou Mountains Salamander--Northern
Portion of the Range
As discussed in detail above under the Species Information: Land
Management section, in anticipation of the eventual removal of the
Survey and Manage Program, a team of researchers and biologists from
USFS Pacific Northwest Research Station and the Service formalized the
existing Survey and Manage Category D objectives for the Siskiyou
Mountains salamander in the northern portion of its range (Applegate
salamander) in a Conservation Strategy (Olson et al.
[[Page 4397]]
2007). The USFS and BLM committed to implement this Conservation
Strategy in the August 16, 2007, Conservation Agreement for the
Siskiyou Mountains Salamander (Plethodon stormi) in Jackson and
Josephine Counties of southwest Oregon and in Siskiyou County of
northern California (USDA and USDI 2007; Olson et al. 2007). However,
because of the limited nature of the threats addressed by the
conservation Strategy, we did not rely on it in determining whether
listing the Siskiyou Mountains salamander is warranted.
The petitioners (Greenwald and Curry 2007, p. 9) questioned whether
the BLM will adhere to the Conservation Agreement because it is not
incorporated into the proposed Western Oregon Plan Revision (WOPR)
Draft Environmental Impact Statement (DEIS), a proposal to modify the
NWFP land allocations and standards and guidelines on BLM lands in
Oregon, which could potentially increase timber harvest levels on BLM
lands within the range of the salamanders. Because we did not rely on
the Conservation Strategy in reaching our determination, the
petitioners' concern is not relevant. In any case, the timing of
development and release of the WOPR DEIS precluded inclusion of the
then-unsigned Conservation Agreement; the BLM has subsequently provided
a letter to the Service clarifying the BLM's commitment to implement
the Conservation Strategy regardless of the eventual outcome of the
WOPR proposal (USDI 2007b).
The petitioners also question the ability of the Conservation
Agreement to conserve the Siskiyou Mountains salamander because it
protects only roughly half of the currently known salamander locations
and allows management of fire risk at 48 locations (Greenwald and Curry
2007, pp. 10-11). Petitioners apparently assume that only the selected
high-priority sites will receive any degree of protection, management
guidelines designed to reduce fire risk at 48 sites will harm
populations, and significant losses of Applegate salamander populations
not specifically protected by the strategy are likely. Although we did
not rely on the Conservation Strategy in reaching our conclusion, we
note that the available information does not support these assumptions.
It is unlikely that a high proportion of the non-network sites are at
risk because of other protections in place. For example, many of the
289 Siskiyou Mountain salamander locations not selected for the
population network fall within NWFP reserves and other areas not likely
to experience intensive disturbance, and, as described above under
Factor A, there is little evidence to suggest that substantial losses
of populations will occur as a result of foreseeable forest management
activities. The Conservation Strategy was authored by four of the most-
published scientific experts on this species (D. Olson, D. Clayton, H.
Welsh, and R. Nauman, among others), and incorporates habitat modeling
and risk assessment in the evaluation of species persistence and
distribution within the strategy area. The petitioners present no
information or analysis to support their contention that the expert
team somehow erred in the development of the Conservation Strategy.
The petitioners assert that the Conservation Strategy is unlikely
to be effective because it contains management recommendations that
appear to lack regulatory force (Greenwald and Curry 2007, p. 10) and
further claim that the Conservation Strategy does not meet the
standards of the Service's Policy for Evaluating Conservation Efforts
(PECE) (68 FR 15100; March 28, 2003) (Greenwald and Curry 2007, p. 11).
In response to the petitioners' first concern, we have no basis to
conclude that the Federal parties to the Conservation Agreement will
fail to comply with their own management guidance, and note that the
Service will be a participant in the 5-year reviews described in the
Strategy under Adaptive Management (Olson et al. 2007, p. 39-40). As
described under ``Background: Land Management,'' the Conservation
Strategy for the Siskiyou Mountains Salamander, Northern Portion of the
Range is simply the formalization of existing Survey and Manage
guidance for northern populations of Siskiyou Mountains salamanders;
guidance deemed adequate by the petitioners (Center for Biological
Diversity et al. 2003, p. 17) and the Survey and Manage taxa team
experts.
In response to petitioners' reliance on PECE, we emphasize that
application of the PECE is inappropriate here. The Service may rely on
conservation efforts that meet the standards of PECE in making listing
determinations. In other words, a conservation effort relied on
consistent with PECE can be dispositive as to the Service's ultimate
finding on the status of a species. The policy therefore requires a
high level of certainty that conservation efforts will be implemented
and will be effective to ameliorate threats that would otherwise
warrant listing of a species. Even in the absence of the Conservation
Strategy, we do not consider the threats to the Siskiyou Mountains
salamander under factors A through E of Section 4(a)(1) of the Act, now
or in the foreseeable future, substantial enough to warrant its listing
under the Act. Therefore, although implementation of the Conservation
Strategy may be beneficial for the Siskiyou salamander, we did not rely
on it in making our determination that the species does not warrant
listing.
Western Oregon Plan Revisions
The WOPR are a proposal by the BLM to revise six resource
management plans (RMPs) that cover all BLM-administered lands in
western Oregon. In August 2003, the American Forest Resource Council,
the Association of Oregon and California Counties, and the Secretaries
of Interior and Agriculture entered into a settlement agreement
requiring the BLM to revise its RMPs to meet the mandated requirements
of the Oregon and California Railroad and Coos Bay Wagon Road Grant
Lands Act of 1937. In accordance with this agreement, the BLM is
proposing to revise existing RMPs to replace the NWFP land-use
allocations and management direction. In its August 16, 2007, DEIS for
the Revision of the Western Oregon RMPs, the BLM describes three action
alternatives designed to meet the purpose and need of the plan
revisions, and a no-action alternative. Each of the action alternatives
includes a range of management strategies; however, none of the action
alternatives propose to retain NWFP late-successional reserves, and all
action alternatives would result in a reduction in riparian reserve
areas.
While these proposed revisions have the potential to increase
timber harvesting within the range of the Siskiyou Mountains
salamander, we cannot at this time predict which alternative, including
the no action alternative, will be selected or evaluate the potential
effects to the 11 percent of the range of the Siskiyou Mountains
salamander that occurs on lands administered by BLM in Oregon.
While the potential effects of possible RMP changes on the small
percentage of Siskiyou Mountains salamander's range that occurs on BLM
lands are unknown, NWFP land-use allocations and management direction
provides substantial protection for the Siskiyou Mountains salamander
and its habitat. If existing Federal management for the Siskiyou
Mountains salamander is modified in the future, the Service can
consider any such changes in the context of the degree and immediacy of
potential threats to the Siskiyou Mountains salamander at that time.
[[Page 4398]]
State Regulations
In California, the Siskiyou Mountains salamander is listed as a
threatened species and receives substantial protection pursuant to
CESA. On private timberlands, this protection includes a requirement
for pre-project surveys and prohibitions on timber harvest in
established buffers around occupied suitable habitat. In May 2005, CDFG
submitted a petition to the California Fish and Game Commission to
delist the Siskiyou Mountains salamander throughout its entire range in
California. In August 2005, CDFG amended the petition by removing that
portion of the Siskiyou Mountains salamander's range that is now known
to be occupied by the recently described Scott Bar salamander. The
private lands affected by the amended petition consititute only 9
percent of the known range of the Siskiyou Mountains salamander in
California. The final determination on whether to delist the Siskiyou
Mountains salamander was scheduled to be made at the Fish and Game
Commission's January 31, 2007, meeting; however, that decision has been
postponed pending completion of environmental documents. Because of
controversy surrounding the proposed delisting, it is uncertain whether
the existing regulatory protections will be removed in the foreseeable
future. If existing State regulations are modified in the future, the
Service can consider such changes in the context of the degree and
immediacy of potential threats to the Siskiyou Mountains salamander at
that time. However, because of the small proportion of the species'
range that occurs on private lands in California, combined with
evidence that Siskiyou Mountains salamander populations persist in
disturbed habitats, we find that removal of CESA protections would not
pose a substantial threat to the species.
No specific regulatory mechanisms to protect the Siskiyou Mountains
salamander exist on the approximately seven percent of the species'
range that occurs on private lands in Oregon. However, most of these
lands occur as small (one square mile or less) parcels distributed in a
checkerboard pattern or as isolated parcels within Federal lands where
management is more favorable for salamanders and serves to maintain
redundancy, distribution, and connectivity among Siskiyou Mountains
salamander populations. In addition, research indicates that
populations of Siskiyou Mountains salamander persist following timber
harvesting and recover as vegetation is re-established (see Factor A).
Therefore, the Service believes that the lack of regulatory protections
on a small proportion of the species' range in Oregon does not pose a
threat to the species in the foreseeable future.
Summary of Factor D
The adequacy of existing regulatory mechanisms to protect Siskiyou
Mountains salamander populations must be evaluated in light of the
degree of threat potentially posed by the actions being regulated. As
described above under Factor A, Siskiyou Mountains salamander
populations may find optimum habitat conditions in mature forest, but
also occupy a wide range of forest conditions and have been shown to
persist and recover following disturbances such as timber harvesting
and fire. Although not specifically aimed at conservation of Siskiyou
Mountains salamanders, land management guidance such as the NWFP and
other regulations provide protection of salamander habitat on Federal
lands which constitute the vast majority of the species' range.
Although we have determined that the species does not warrant listing
even in the absence of any reduction in threat resulting from
implementation of the Conservation Strategy for the Siskiyou Mountains
salamander (Plethodon stormi) in the Northern Portion of the Range
(Olson et al. 2007), that Conservation Strategy may provide an added
layer of security to the Northern Clade of Siskiyou Mountains
salamander populations.
Current California regulations provide substantial protection for
the Siskiyou Mountains salamander on the small percentage of the
species' range in California that occurs on private lands. The
California Fish and Game Commission is currently evaluating a petition
to delist the Siskiyou Mountains salamander, but has not reached a
decision regarding this action. However, we find that the removal of
CESA protections would not pose a substantial threat to the species,
because of the small proportion of the species' range that occurs on
private lands in California, combined with evidence that Siskiyou
Mountains salamander populations persist in disturbed habitats. Oregon
does not provide regulatory protections for the Siskiyou Mountains
salamander on private lands. However, private lands in Oregon comprise
only seven percent of the Siskiyou Mountains salamander's entire range
(both clades) and are scattered among Federal lands that compose the
vast majority of the species' range.
Under Section 4(a)(1)(D) the Service must evaluate the adequacy of
existing regulatory mechanisms rather than speculate about future
changes to those mechanisms. With the exception of the Survey and
Manage guidelines, which have been eliminated for future projects on
Federal lands, we assume that the NWFP and other land management
regulations will continue as existing regulatory mechanisms that
provide adequate conservation of Siskiyou Mountains salamanders. If
Federal or State regulatory mechanisms are modified or eliminated in
the future, the Service can consider that information when evaluating
the adequacy of then existing regulatory mechanisms to protect the
Siskiyou Mountains salamander in the context of the degree and
immediacy of potential threats to the Siskiyou Mountains salamander at
that time.
In light of the ability for Siskiyou Mountains salamander
populations to persist in managed landscapes, we find that existing
Federal regulatory mechanisms such as the NWFP and other provisions of
Federal Land and Resource Management Plans, in combination with the
Federal Special Status Species programs, offer adequate protection for
the Siskiyou Mountains salamander and its habitat over the vast
majority of its range, and conclude that this species is not now, or in
the foreseeable future, threatened by inadequate regulatory mechanisms.
Factor E: Other Natural or Manmade Factors Affecting the Continued
Existence of the Species
Other natural or manmade factors that may affect the persistence of
the Siskiyou Mountains salamander within all or a significant portion
of its range are climate changes associated with global warming and
stochastic events, which are rare, chance events, such as epidemics and
large, severe wildfires.
Climate Change
There is considerable uncertainty associated with projecting future
climate changes. This uncertainty is partly due to uncertainties about
future emissions of greenhouse gases and to differences among climate
models and simulations (Stainforth et al. 2005, pp. 403-406; Duffy et
al. 2006, p. 874). We are not aware of any climate change simulations
for the Klamath-Siskiyou region, but the results of numerous climate
change simulations for California and the Pacific Northwest have been
published (see below). Together, these simulations describe a range of
plausible outcomes from increased emissions of greenhouse gases.
[[Page 4399]]
All studies we reviewed predicted continued increases in average
surface temperatures in California and the Pacific Northwest in
response to increased emissions of greenhouse gases (Leung and Ghan
1999, p. 2031; Snyder et al. 2002, p. 1; EPRI 2003, p. 95; Hayhoe et
al. 2004, p. 12422; Cayan et al. 2006, p. 11; Duffy et al. 2006, p.
873; Maurer 2007, p. 317; Salath[eacute] et al. submitted, pp. 8-9).
The magnitude of projected increases in annual average temperature
varied widely among studies, depending on the models and emissions
scenarios used, from 3 to 10.4 degrees Farenheit ([deg]F) (1.5 to 5.8
degrees Celsius ([deg]C)), by the year 2100 (EPRI 2003, p. 3; Hayhoe et
al. 2004, p. 12423; Cayan et al. 2006, pp. 11-14; Maurer 2007, p. 317).
Simulations consistently project more pronounced temperature increases
in California during the summer months than during other times of the
year, 3.9 to 14.9 [deg]F (2.2 to 8.3 [deg]C) by 2100 (Hayhoe et al.
2004, p. 12422; Cayan et al. 2006, p. 14; Maurer 2007, p. 317). Some
simulations projected more rapid temperature increases at higher
elevations than at lower ones (Leung and Ghan 1999, p. 2047;
Salath[eacute] et al. submitted, pp. 10-12). Most researchers
attributed this difference to a snow-albedo feedback effect; this
occurs when increased surface temperatures cause earlier and faster
snow melt, which, in turn, allows more absorption of heat by the ground
and further increases in surface temperatures.
Increased average surface temperatures could cause soils used by
Siskiyou Mountains salamanders to become warmer, and possibly drier,
during the dry season. If this occurs, it could negatively affect these
species because they are associated with cool, moist soil conditions
(see Habitat Associations above). However, we expect that the Siskiyou
Mountains salamanders will be somewhat buffered from changes to soil
surface conditions because they are primarily active below ground
during the dry season. Salamanders at shallow sites may be more
negatively affected by drying and heating of the soil surface than
those at deeper sites since they will be less able to respond to
changing soil microclimates with vertical movements. Increased surface
temperatures could have unpredictable indirect effects on these
species: For example, through effects on vegetation, disturbance
regimes, competitors, predators, or prey.
Reviews of a large number and variety of climate change simulations
found that projected changes to precipitation in California were highly
variable but clustered around no change or a slight increase in annual
precipitation (Cayan et al. 2006, p. 17; Maurer 2007, p. 317). Warming
temperatures are consistently projected to increase the proportion of
precipitation that falls as rain rather than as snow in California and
the Pacific Northwest (Leung and Ghan 1999, p. 2041; Snyder et al.
2002, p. 3; Hayhoe et al. 2004, p. 12425; Cayan et al. 2006, p. 31;
Maurer 2007, p. 319). Earlier and more rapid snowmelt and decreases in
the proportion of precipitation that falls as snow are expected to
cause declines in spring snowpacks (Hayhoe et al. 2004, p. 12422; Cayan
et al. 2006, p. 31; Maurer 2007, p. 309). Declines in spring snowpacks
have already occurred in some areas and are correlated with global
warming trends (Mote 2003, pp. 1-4). Some areas will experience
increased cloud cover as surface temperatures continue to increase
(Croke et al. 1999, pp. 2128-2134). One model projected a greater
increase in low cloud cover during spring in the Pacific Northwest,
especially near the coast (Salath[eacute] et al. submitted, pp. 14-16).
Lower proportions of snow versus rain and earlier and faster
snowmelt could enable the Siskiyou Mountains salamanders to become
surface active earlier in the spring. We currently do not know whether
or how a shift in the timing of surface activity might affect the
viability of these species. Little is known about the physiological
sensitivities of the Siskiyou Mountains salamanders to temperature, but
an increase in spring cloud cover could directly benefit them by
moderating daily temperature ranges during their periods of surface
activity. Superficially, increased precipitation might also directly
benefit the species, while decreased precipitation might negatively
affect it. For example, changes to the timing and amount of
precipitation could alter the length or frequency of the species'
periods of surface activity or the size or location of its geographic
range. Changes to cloud cover or the amounts, timing, and form of
precipitation could also have complex indirect effects on the species;
for example, through influences on vegetation, disturbance regimes,
competitors, predators, or prey. Evaluation of the potential effects of
changes to precipitation on the Siskiyou Mountains salamander should
become more meaningful as emissions scenarios, climate change models,
and our knowledge of these species continue to improve.
Vegetation modeling by Lenihan et al. (2003a, pp. 1-41; 2003b, pp.
1667-1681) projected that increased emissions of greenhouse gases will
cause large-scale replacement of evergreen conifer forest (e.g.,
Douglas fir-white fir) with mixed evergreen forest (e.g., Douglas-fir-
tanoak) in the Klamath-Siskiyou region. This redistribution of
vegetation types is predicted to occur under conditions created by two
contrasting climate change models (Lenihan et al. 2003a, pp. 23-25).
Because Siskiyou Mountains salamanders already occur within mixed
evergreen forest, we do not anticipate a direct negative effect to the
species from this potential change. However, the species may shift its
range to higher elevations, following elevational changes in climate
and vegetation. Numerous indirect effects of community composition
shifts on the Siskiyou Mountains salamander could occur, but the net
effect of these shifts is currently impossible to predict owing to the
lack of information about this species' ecology.
Despite variability in climate change simulations, consistent
projections for warmer summers, reduced spring snowpacks, and earlier
and more rapid snowmelt suggest that forests in California and the
Pacific Northwest will experience longer fire seasons and more
frequent, extensive, and severe fires in the future (Flannigan et al.
2000, pp. 221-229; Lenihan et al. 2003a, p. 18; Whitlock et al. 2003,
pp. 13-14; McKenzie et al. 2004, pp. 897-898). However, inconsistent
predictions for precipitation, including increased cloud cover and
rainfall, make this outcome uncertain.
The Siskiyou Mountains salamander has experienced other large
changes to global and regional climates during its history. For
example, global temperatures during the Pliocene warm period (5 to 3
million years ago) were approximately 5.4 [deg]F (3 [deg]C) higher than
today (Ravelo et al. 2004, p. 263). More recently, several large
changes to climate, fire regimes, and vegetation occurred in the
Klamath-Siskiyou region during the Holocene (approximately 12,000 years
to present day) (e.g., Mohr et al. 2000). Little is known about how the
Siskiyou Mountains salamander responded to prehistoric climate changes
or how those responses might inform us about the impacts of future
changes.
Stochastic Events
Siskiyou Mountains salamanders have relatively small geographic
ranges and limited dispersal abilities. Analyses of the fossil record
and of currently threatened species suggest that species with these
characteristics are at a higher risk of extinction than are mobile,
widely distributed species (Jablonksi
[[Page 4400]]
1986; Manne et al. 1999; Dynesius and Jansson 2000; Jones et al. 2003;
Payne and Finnegan 2007). Stochastic (rare, chance) events such as
epidemics or large, severe fires can threaten the persistence of
species with restricted ranges because a single event can occur within
all or a large portion of their ranges. Species that are relatively
sedentary are probably less able than mobile animals to escape
stochastic events and their effects, or to recolonize parts of their
range where they have been extirpated. Some researchers have suggested
that the Siskiyou Mountains salamander is rare and patchily
distributed, which could further increase the species' risks of
extinction. However, the evidence cited above suggests that this
salamander is in fact well distributed within its range, that it likely
occurs at high densities in some areas, and that it persists in areas
that have experienced disturbances (see Range and Distribution, and
Factor A).
Epidemics and large, severe fires are two kinds of stochastic
events that could negatively affect populations of the Siskiyou
Mountains salamander. However, these events are unlikely to threaten
the persistence of the species across its range. The only lethal
disease we are aware of that could behave as an epidemic in populations
of this salamander is chytridiomycosis (Batrachochytrium
dendrobatidis), but this species does not appear likely to contract
this disease and the Siskiyou Mountains salamander's life history makes
it unlikely that this disease would spread as an epidemic (see Factor C
above). The Siskiyou Mountains salamander is probably more likely to
experience large, severe wildfires than epidemics in the foreseeable
future. Wildfires can occur over large areas relative to the range of
the Siskiyou Mountains salamander. For example, 499,965 ac (202,329 ha)
burned during the 2002 Biscuit Fire in southwestern Oregon and
northwestern California, largely outside of the range of the
salamanders. Approximately 44 percent of the area (219,985 ac (89,025
ha)) was severely burned (USDA and USDI 2004). In comparison, the
species range of the Siskiyou Mountains salamander is 423,155 ac
(171,241 ha). However, Siskiyou Mountains salamanders appear to be
relatively resilient to disturbances (see Factor A above), having
evolved in a region where large wildfires are characteristic. Further,
past fire behavior and modeling of future fire behavior suggest that
large, severe fires in this region will have a mosaic of effects,
leaving unburned and lightly burned patches of suitable habitat for the
species in some areas (see Factor A above).
Summary of Factor E
Uncertainty is associated with predicting future climate changes,
but simulations have consistently projected continued increases in
average surface temperatures, reduced spring snowpacks, and a lower
proportion of precipitation falling as snow during this century. Given
its physiology, this species may be strongly affected, positively or
negatively, by changes to precipitation patterns. However, projections
of future patterns of precipitation are highly variable for northern
California and southern Oregon, precluding any reliable prediction of
future effects on salamander populations.
The Siskiyou Mountains salamander has a relatively small geographic
range, restricted habitat associations, and limited dispersal
abilities, which could make it more vulnerable to stochastic events
such as large, severe fires than species without these characteristics.
Large, severe fires are also expected to increase in frequency in the
Klamath-Siskiyou region due to global warming and other anthropogenic
factors. However, the high variability of wildfire effects at landscape
scales, coupled with the apparent ability of the species to persist and
eventually recover following habitat disturbance (see Factor A above),
indicates that the Siskiyou Mountains salamander has a high likelihood
of persistence in the foreseeable future. In addition, land management
agencies within the ranges of the salamanders are actively conducting
fuels management treatments to reduce the likelihood of wide-scale
catastrophic fire. The future effectiveness of these treatments is
unknown, but evidence suggests that at least local reductions in fire
severity will be achieved. Therefore, we conclude that the Siskiyou
Mountains salamander is not now, or in the foreseeable future,
threatened by the individual or cumulative effects of climate change,
or stochastic events such as epidemics or large, severe wildfires
across its range.
Finding
We have carefully assessed the best scientific and commercial
information available regarding threats faced by the Siskiyou Mountains
salamander. We have reviewed the petition, information available in our
files, and all information submitted to us following our 90-day
petition finding (72 FR 14750; March 29, 2007). We also consulted with
recognized salamander experts and Federal land managers, and arranged
for researchers to initiate field studies to assess the distribution of
genetic entities within the salamander complex, and demographic
response of these species to forest structure.
The petitioners' primary argument for listing the Siskiyou
Mountains salamander is founded on a chain of inferences, which may be
simplified into the following: (1) The salamanders are highly dependent
on old growth forest conditions; (2) disturbances such as timber
harvesting that modify forest structure will extirpate populations; (3)
the extent and magnitude of such disturbances are sufficient to
threaten the species with extinction in the immediate future; (4)
therefore, highly restrictive regulatory mechanisms are critical to
prevent extirpation of populations by timber harvesting or wildfire;
and, finally, (5) existing regulatory mechanisms are inadequate to
ameliorate the perceived threats to the species. We find that there is
little evidence to support any of the five above-mentioned assertions.
The available information indicates that, while habitat conditions
associated with dense mature forests may be optimal for the Siskiyou
Mountains salamander, populations occupy a wide range of habitats that
provide the requisite elements of shading, moisture, and cover.
Salamander populations are found in a wide variety of forest
conditions, including areas with evidence of past disturbances. Local
abundance and fitness of populations may be negatively affected by more
intensive timber harvesting and wildfires, but salamander populations
appear to persist and recover as vegetation is re-established following
such intense disturbances, and these intensive timber harvest practices
such as clear-cutting are severely restricted on the Federal lands that
constitute the majority of the species' range. Less-intensive harvest
practices appear to have relatively minor or short-term impacts on
salamander abundance, and there are many known populations on managed
timberlands. There is no reliable evidence that indicates loss of
populations or curtailment of the species' ranges has occurred.
Federal lands managed under the provisions of the NWFP comprise the
majority of the Siskiyou Mountains salamander's range. The NWFP acts to
protect salamanders and their habitat via a system of reserves and land
management guidelines that dramatically reduce the likelihood of large-
scale reduction of suitable habitat. Additional land allocations and
management guidance in Federal land management planning documents
[[Page 4401]]
(retention areas, Roadless Areas) and the Federal agencies' Special
Status Species programs provide additional layers of security against
any long-term threats posed by timber harvesting or other land
management activities.
Private lands comprise only about 10 percent of the species' range,
and receive a relatively greater amount of timber harvesting.
Currently, the Siskiyou Mountains salamander is listed under CESA and
receives substantial protection on private lands in California;
however, the future of these protections is uncertain. Regardless of
the eventual CESA status of the species in California, habitat impacts
on private land are not expected to pose a substantial threat to the
Siskiyou Mountains salamander, because: (1) Private lands constitute a
small minority of the species' range; (2) private lands exist in a
checkerboard pattern of small (less than one square mile) parcels
interspersed among Federal lands where management is more favorable and
therefore, acts to maintain redundancy, distribution, and connectivity
among populations within the mix of Federal and private lands; (3)
salamander populations appear to persist and recover following timber
harvesting; and (4) many salamander populations are known to occur on
private timberlands despite a long history of timber harvesting.
Wildfires are expected to occur and may reduce habitat quality for
some salamander populations; however, the effects of wildfire on
salamander habitat are temporary and populations appear to recover as
vegetation recovers. Wildfires in the Klamath-Siskiyou region typically
burn in a mosaic pattern of intensities, leaving a variety of habitat
conditions for salamanders within burned areas. We also note that
Federal Federal land management agencies are actively planning and
conducting fuels reduction treatments to reduce the threat of large,
stand-replacing wildfires within the range of the Siskiyou Mountains
salamander.
Within its relatively small range, populations of Siskiyou
Mountains salamanders are well distributed, and abundance within
populations can be high. There are 516 known locations for this
species, and large areas supporting suitable habitat have not been
surveyed. These population characteristics, combined with the species'
apparent ability to persist and recover following habitat disturbance,
indicate that the Siskiyou Mountains salamander is resilient to
stochastic events such as large wildfires. Our evaluation of climate
change modeling for the geographic area inhabited by the salamanders
does not support the contention that climate change poses a substantial
threat to Siskiyou Mountains salamanders. Although most of the
available models predict increases in average temperatures, models were
inconsistent with regard to future precipitation; increases in annual
precipitation and cloud cover are a plausible outcome and could act to
ameliorate any negative impacts caused by increased temperatures. It is
not currently possible to forecast the specific effects of future
climate on salamander populations.
Our evaluation of the threats to the Siskiyou Mountains salamander
leads us to the conclusion that several factors act cumulatively to
assure the continued existence of well-distributed, viable populations
of this species into the foreseeable future. These are: (1) Populations
are demonstrated to persist in a wide variety of habitat conditions;
(2) populations appear to be somewhat resilient to habitat disturbances
such as timber harvesting and fire; (3) to the extent that habitat
disturbances have negative effects to salamander populations, 90
percent of the species' range is protected from substantial negative
impacts by existing Federal land management regulations such as the
NWFP and other regulations that provide protection for their habitat;
(4) private timberlands constitute only 10 percent of the species'
range, and currently support numerous salamander populations; and (5)
the 516 currently known locations of this species are well-distributed
spatially and large areas of suitable habitat have yet to be surveyed.
Therefore, we do not find that the Siskiyou Mountains salamander is in
danger of extinction (endangered) now, nor is it likely to become
endangered within the foreseeable future (threatened) across its range.
Therefore, listing the species range-wide as threatened or endangered
under the Act is not warranted at this time.
Distinct Population Segment
As stated above, the Siskiyou Mountains salamander can be separated
into two clades, the Applegate salamander and the Grider salamander
and, therefore, may be considered as two distinct population segments
(DPSs), if indeed, they meet the criteria to be defined as such.
Section 2(16) of the Act defines ``species'' to include ``any species
or subspecies of fish and wildlife or plants, and any distinct
vertebrate population segment of fish or wildlife that interbreeds when
mature'' (16 U.S.C. 1532 (16)). To interpret and implement the DPS
provisions of the Act and Congressional guidance, the Service and the
National Marine Fisheries Service (now the National Oceanic and
Atmospheric Administration--Fisheries), published a Policy Regarding
the Recognition of Distinct Vertebrate Population Segments in the
Federal Register (DPS Policy) on February 7, 1996, (61 FR 4722). Under
the DPS policy, three factors are considered in the decision concerning
the establishment and classification of a possible DPS. These are
applied similarly for additions to the list of endangered and
threatened species. These factors are (1) the discreteness of a
population in relation to the remainder of the species to which it
belongs, (2) the significance of the population segment to the species
to which it belongs, and (3) the population segment's conservation
status in relation to the Act's standards for listing, delisting, or
reclassification (i.e., is the population segment endangered or
threatened?).
Discreteness
Citing the Services' DPS policy (61 FR 4722) and the best available
information, the June 2006 petition suggests that the Siskiyou
Mountains salamander can be separated into two discrete populations
based on reproductive isolation. Under the DPS policy, a population
segment of a vertebrate taxon may be considered discrete if it
satisfies either one of the following conditions:
(1) It is markedly separated from other populations of the same
taxon as a consequence of physical, physiological, ecological, or
behavioral factors. Quantitative measures of genetic or morphological
discontinuity may provide evidence of this separation.
(2) It is delimited by international governmental boundaries within
which differences in control of exploitation, management of habitat,
conservation status,or regulatory mechanisms exist that are significant
in light of section 4(a)(1)(D) of the Act.
Phylogenetic studies of the Siskiyou Mountains salamander
demonstrate that this species consists of two distinct genetic
lineages: the Applegate salamander (populations within the Applegate
River drainage and north of the Siskiyou Crest) and the Grider
salamander (populations south of the Siskiyou Crest and adjacent to the
Klamath River) (Pfrender and Titus 2001, pp. 5-6; DeGross 2004, pp. 24-
44; Mahoney 2004, p. 8; Mead et al. 2005, pp. 163-166). Mead et al.
(2005, p. 168) describe these lineages as ``a major phylogenetic
subdivision within P. stormi.'' Mead et al. (2005, p. 168) estimated an
average of 2.22 percent
[[Page 4402]]
mitochondrial DNA sequence divergence between the Applegate and Grider
salamanders, compared with 11.5 percent and 11.68 percent sequence
divergence between Scott Bar salamander and the Applegate and Grider
salamanders, respectively. An additional genetic distinction between
the two lineages is the almost complete lack of genetic variation
within and among Applegate populations, likely the result of range
expansion and genetic bottleneck as individuals dispersed into the
southern reaches of the Applegate watershed (Pfrender and Titus 2001,
pp. 5-6).
The geographic ranges occupied by the Applegate and Grider
salamanders are separated by the Siskiyou Crest, a high-elevation ridge
system unlikely to permit population connectivity between the groups.
Analyses of mitochondrial DNA indicate that, while the ancestral
lineage of the Applegate salamander originated south of the Siskiyou
Crest, the two groups diverged over four million years ago (DeGross and
Bury 2007, p. 3), further supporting the conclusion that the Siskiyou
Crest constitutes an effective barrier between the groups.
The Applegate and Grider salamanders are markedly separated as a
consequence of physical (geographic) features, and as a consequence
exhibit genetic divergence as well. We, therefore, conclude that the
two groups are discrete under our DPS policy.
Significance
If a population segment is considered discrete under one or more of
the conditions described in our DPS policy, its biological and
ecological significance will be considered in light of Congressional
guidance that the authority to list DPSs be used ``sparingly'' while
encouraging the conservation of genetic diversity. In making this
determination, we consider available scientific evidence of the
discrete population segment's importance to the taxon to which it
belongs. Since precise circumstances are likely to vary considerably
from case to case, the DPS policy does not describe all the classes of
information that might be used in determining the biological and
ecological importance of a discrete population. However, the DPS policy
does provide four possible reasons why a discrete population may be
significant. As specified in the DPS policy (61 FR 4722), this
consideration of the population segment's significance may include, but
is not limited to, the following:
(1) Persistence of the discrete population segment in an ecological
setting unusual or unique to the taxon;
(2) Evidence that loss of the discrete population segment would
result in a significant gap in the range of a taxon;
(3) Evidence that the discrete population segment represents the
only surviving natural occurrence of a taxon that may be more abundant
elsewhere as an introduced population outside its historic range; or
(4) Evidence that the discrete population segment differs markedly
from other populations of the species in its genetic characteristics.
A population segment needs to satisfy only one of these criteria to
be considered significant. Furthermore, the list of criteria is not
exhaustive; other criteria may be used as appropriate.
The ranges and population distribution of the Applegate and Grider
salamanders suggest that the loss of either group would result in a
significant gap in the range of the Siskiyou Mountains salamander. The
estimated ranges of the Applegate and Grider salamanders constitute
about 59 percent and 41 percent, respectively, of the overall range of
the Siskiyou Mountains salamander. Loss of such a substantial portion
of the species' range, coupled with the dispersal barrier posed by the
Siskiyou Crest, would be significant to the distribution of the
species. An additional consideration is the metapopulation-level
redundancy that the two groups provide each other. Climatic conditions
and fire regimes differ on either side of the Siskiyou Crest, and the
elevation of the Crest itself serves as a barrier to wildfires. Large-
scale disturbances such as catastrophic wildfire may therefore act
independently on either clade; allowing the continued persistence of
the species in the event of substantial losses of one group.
The uneven distribution of genetic variation across the range of
the Siskiyou Mountains salamander places a disproportionate
significance on each group for the maintenance of genetic diversity in
the species. The Applegate salamander exhibits a strikingly low level
of genetic variation, and is divergent from the more variable Grider
salamander (Pfrender and Titus 2001, pp. 5-6; Mead et al. 2005, pp.
166-169). Loss of either genetically distinct group would pose a
substantial reduction in genetic diversity of Siskiyou Mountains
salamander. Therefore, we consider the Applegate and Grider salamanders
significant to the taxon as a whole under our DPS policy.
Conclusion of Distinct Population Segment Review
Based on the best scientific and commercial information available,
as described above, we find that under our DPS policy, the Applegate
and Grider salamander groups of the Siskiyou Mountains salamander are
discrete and each are significant to the overall species. Because the
Applegate and Grider salamanders are both discrete and significant,
they warrant recognition as separate DPSs under the Act.
Since we have identified the Applegate and Grider salamanders as
two separate, valid DPSs, we will evaluate each DPS with regard to its
potential for listing as threatened or endangered using the five
listing factors enumerated in Section 4(a) of the Act. Our evaluation
of the Applegate salamander DPS follows.
Applegate Salamander Distinct Population Segment
As described above, Section 4 of the Act (16 U.S.C. 1533) and
implementing regulations (50 CFR part 424) describe procedures for
adding species to the Federal Lists of Endangered and Threatened
Wildlife and Plants. Under section 4(a), we may list a species on the
basis of any of five factors: (A) The present or threatened
destruction, modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence.
An endangered species is defined by the Act, with exception, as
``any species which is in danger of extinction throughout all or a
significant portion of its range.'' A threatened species is defined as
``any species which is likely to become an endangered species within
the foreseeable future throughout all or a significant portion of its
range.'' A species is defined by the Act to include ``any subspecies of
fish or wildlife or plants, and any distinct population segment of any
species of vertebrate fish or wildlife which interbreeds when mature.''
Factor A: The Present or Threatened Destruction, Modification, or
Curtailment of the Species' Habitat or Range
Our understanding of the habitat associations of the Applegate
salamander DPS, and the potential effects of habitat perturbations such
as timber harvest and fire on this
[[Page 4403]]
salamander, is based primarily on research conducted across the range
of the entire Siskiyou Mountains salamander Complex. The available
information indicates that the members of the Complex have similar
physiological and behavioral characteristics, and consequently similar
habitat associations. This conclusion is supported by Welsh et al.
(2007a, p. 31), who state that the genetic subunits of Siskiyou
Mountains salamander ``do little if anything to alter their basic eco-
physiological limits (e.g., Spotila 1972; Feder 1983) and consequent
similar environmental requirements imposed by the plethodontid life
form.'' We recognize that the range of the Applegate salamander DPS is
roughly 60 percent of the area occupied by the entire Siskiyou
Mountains salamander, and that the relative magnitude of effects caused
by habitat perturbations may be different at this smaller spatial
scale. We have incorporated these differences of scale into our
analysis. Given this caveat, we believe that the potential effects of
timber harvesting, fire, and other habitat perturbations on the
Applegate salamander DPS are the same as those described previously for
the Siskiyou Mountains salamander. To avoid redundancy, these effects
are summarized below; further detail and citations may be found in the
Factor A analysis for the Siskiyou Mountains salamander.
Effects of Timber Harvesting on the Applegate Salamander DPS
Rigorous research of the effects of timber harvesting on these
salamanders is lacking, but the available evidence suggests that
intensive timber harvest practices such as clear-cutting have a short-
term (30 years) negative impact on abundance, age structure, and body
condition of this DPS. However, it is also clear that the salamanders
frequently persist in intensively harvested areas, and that populations
recover as vegetation is re-established (Welsh et al. 2007b). There is
no information indicating that populations are extirpated in
intensively harvested sites. Alternative timber harvesting methods such
as thinning and helicopter yarding have not been shown to have negative
effects on populations of this DPS.
Extent and Magnitude of Timber Harvesting Effects on the Applegate
Salamander DPS
The extent and magnitude of potential effects caused by timber
harvesting are strongly limited by existing land management regulations
on the majority of the range of this DPS. Approximately 85 percent of
the range of the Applegate salamander DPS consists of Federal lands
managed under the provisions of the NWFP; 66 percent is administered by
the USFS and 19 percent by the BLM. Roughly 33 percent of the range
occurs within reserves (Late-successional Reserves, Wilderness,
Riparian Reserves) withdrawn from scheduled timber harvesting; 42
percent of the range is in the Applegate Adaptive Management Area; and
9 percent is in Matrix. Of the three members within the Siskiyou
Mountains salamander Complex, the Applegate salamander DPS has the
lowest proportion of its range protected in reserves.
The rate and intensity of timber harvesting has declined
substantially on Federal lands within the range of the Applegate
salamander DPS during the past 20 years. Annual timber harvesting on
the Rogue River National Forest, which comprises 66 percent of the DPS
range, declined from an average of 182 million board feet during the
1980s to 8 million board feet per year from 2000 to 2006, a decrease of
96 percent (USDA 2007c). The Applegate Ranger District, which comprises
roughly 66 percent of the DPS range, has completed only one timber sale
since 1996 (Clayton 2007b). Similarly, the rate of timber harvest has
declined substantially on BLM lands within the range of the Applegate
salamander DPS. Mean annual harvest on the BLM Ashland Resource Area
declined from 2,240 ac (907 ha) per year between 1995 and 2000, to 664
ac (269 ha) per year between 2001 and 2007; less than 270 ac (109 ha)
per year have been harvested since 2003 (USDI 2007a). The intensity of
timber harvest practices on Federal lands has declined dramatically as
well. For example, on the BLM's Ashland Resource Area, intensive
harvest methods such as clear-cutting have declined from 54 percent of
acres harvested in the mid-1990s, to less than one percent of annual
harvest since 2001 (USDI 2007a). The likelihood that a substantial
proportion of the Applegate salamander DPS will be affected by
intensive timber harvesting is greatly reduced by the long-term
declining trend in the rate and intensity of timber harvesting. The
BLM's proposal to increase timber harvest levels by revising their RMPs
has an uncertain outcome, and we see no reason to forecast a
significant increase in timber harvest levels in the foreseeable
future.
Intensive timber harvesting practices such as clear-cutting and
shelterwood removal are more prevalent on private timberlands, which
comprise only 15 percent of the range of the Applegate salamander DPS.
Approximately 12 percent of the DPS range occurs on private timberlands
in Oregon; 3 percent lies in California. The majority of private lands
within the range of the Applegate salamander DPS occur as small parcels
(typically one square mile or less) in a checkerboard pattern
surrounded by Federal lands, or as small isolated parcels. Populations
of the Applegate salamander DPS on private lands may be affected by
timber harvesting but are dispersed among populations on Federal lands
where management is more favorable. Since the distribution of private
lands occurs within a larger matrix of Federal lands, this acts to
disperse any negative impacts of timber harvesting on Applegate
salamander DPS populations and maintains redundancy, distribution, and
connectivity among salamander populations. Therefore, no one area
within the range of the Applegate salamander DPS has significantly
greater threats from timber harvesting on private lands.
Wildfire
Based on the best scientific and commercial information available,
we believe the potential effects of wildfire on the Applegate
salamander DPS are similar to those described previously for the
Siskiyou Mountains salamander. When they occur, wildfires typically
burn in a range of intensities, resulting in a mosaic of habitat
effects. Intense, stand-replacing fire likely reduces habitat quality
for this DPS by reducing overstory cover and consuming moss, duff and
forest floor litter, thereby modifying suitable microclimate habitat.
However, as shown for the effects of intensive timber harvesting,
Siskiyou Mountains salamander populations appear to persist and recover
as vegetation is re-established after severe habitat disturbances. The
degree to which wildfires affect the viability of salamander
populations is unknown, but it is likely that large-scale intense
wildfires may negatively affect some populations.
The potential threat posed by wildfire to the Applegate salamander
DPS was evaluated by Olson et al. (2007, p. 25, Appendix 2 p. 5). The
authors combined a habitat suitability model (Reilly et al. 2007) with
spatial data on various risk factors such as wildfire hazard and NWFP
land use allocations into a GIS and developed a range-wide map
depicting risk to persistence of salamander populations. Extensive
areas of highly suitable habitat and lower fire hazard were predicted
on north-facing slopes, such as the north slope of the
[[Page 4404]]
Siskiyou Crest (Olson et al. 2007, Appendix 2 p. 8).
While there is uncertainty concerning the potential population-
level effects of wildfire on the Applegate salamander DPS, we expect
that wildfires will occur and may reduce habitat quality for some
salamander populations. However, the effects of wildfire are unlikely
to result in widespread loss of population viability because: (1) Fires
typically burn in a mosaic of effects, leaving a variety of habitat
conditions for salamanders occupying burned areas; and (2) these
salamanders persist in disturbed areas and recover as vegetation
recovers, allowing for persistence and recovery of local salamander
populations. In addition, land management agencies within the range of
this DPS are actively conducting fuels management treatments to reduce
the likelihood of wide-scale catastrophic fire. The future
effectiveness of these treatments is unknown, but evidence suggests
that at least local reductions in fire severity will be achieved.
Direct Disturbance: Roads and Road Construction, Mining, and Rock
Quarrying
As described under Factor A for the Siskiyou Mountains salamander,
activities that physically alter the talus substrates occupied by the
Applegate salamander DPS have the potential to reduce habitat quality
or remove habitat. In addition, some research suggests that forest
roads may pose a barrier to these salamanders, reducing dispersal and
connectivity among populations. We find that, while it may reasonably
be expected that crushing or removal of talus habitat during road
construction, mining, or rock quarrying could negatively affect
Applegate salamander populations, these activities affect only a very
small area of the DPS's range. Further, numerous records exist of the
salamanders occupying road cuts and sites with historical mining
activity, and the rate of road construction, which is typically
associated with access for timber harvesting, has declined
significantly as timber harvest levels have decreased. There is little
potential for a substantial portion of Applegate salamander DPS
populations to be affected by direct disturbance from road
construction, mining, or rock quarrying. For these reasons, we conclude
that road construction, mining and rock quarrying do not pose a
substantial threat to this DPS; a conclusion echoed by species experts
(Olson et al. 2007, p. 17).
Summary of Factor A
While intensive timber management practices such as clear-cutting
appear to have short-term negative effects on abundance of Applegate
salamanders, this practice is severely restricted on Federal lands,
which constitute the majority of the DPS's range. Less-intensive
harvest practices appear to have relatively minor or short-term impacts
to salamander abundance, and the available evidence suggests that
salamander populations persist in a broad range of forest habitat
conditions and under different management practices.
Current management on Federal lands under the provisions of the
NWFP protects salamander habitat via a system of reserves and
management guidelines that dramatically reduce the likelihood of large-
scale reduction of suitable or occupied habitat; additional Federal
land management direction and the Special Status Species programs
provide additional security to salamander populations on non-reserved
Federal lands. Management practices on private timberlands may
negatively affect some populations of the Applegate salamander DPS;
however, due to the patchy distribution of private lands within the
larger matrix of Federal lands, and the ability of these salamanders to
persist in managed habitats, we conclude that habitat modifications on
this small portion of the Applegate salamander DPS's range do not
constitute a substantial threat to the DPS.
Wildfires are expected to occur and may reduce habitat quality for
some salamander populations; however, the effects of wildfires on
salamander habitat are temporary and populations appear to recover as
vegetation recovers. Wildfires typically burn in a mosaic pattern of
intensities, leaving a variety of habitat conditions for salamanders
within burned areas. In addition, Federal land management agencies are
planning and conducting fuels reduction treatments to reduce the threat
of stand-replacing wildfires within the range of the Applegate
salamander.
Although relatively undisturbed mature forests may provide optimum
habitat for Applegate salamanders; these salamanders have been shown to
exist in a range of habitat conditions that have experienced timber
harvesting, wildfire, and other disturbances such as mining and
quarrying, and evidence suggest that populations persist and recover
following habitat disturbance. Intense disturbances such as clear-
cutting are highly limited by current land-use regulations, and along
with rock quarrying and road construction constitute a tiny fraction of
the DPS's habitat. Therefore, we conclude that the Applegate salamander
DPS is not now, or in the foreseeable future, threatened by
destruction, modification, or curtailment of its habitat across its
range.
Factor B: Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
We are not aware of any information that indicates overutilization
for commercial, recreational, scientific, or educational purposes
threatens the Applegate salamander DPS, now or in the foreseeable
future, across its range.
Factor C: Disease or Predation
Chytridiomycosis is a relatively recently described epidermal
infection of amphibians caused by the chytrid fungus Batrachochytrium
dendrobatidis. This fungus requires moisture for survival (Johnson and
Speare 2003, p. 922) and is therefore more likely to pose a threat to
aquatic amphibians than to terrestrial ones. As described for the
Siskiyou Mountains salamander, we do not anticipate that the Applegate
salamander DPS will be exposed to this disease or that exposure would
lead to transmission through significant portions of its range.
Salamanders composing this DPS are not associated with bodies of water,
occur in a characteristically dry environment, are only active above
ground for brief and intermittent periods during the year, and appear
to have limited dispersal abilities. Given these circumstances, we
believe that the Applegate salamander DPS is unlikely to be exposed to
diseased water or infected aquatic amphibians and, if infected,
salamanders are unlikely to transmit the disease between populations.
The Service is not aware of any predators that potentially pose a
threat to the species. We, therefore, conclude that the Applegate
salamander DPS is not now, or in the foreseeable future, threatened by
disease or predation across its range.
Factor D: Inadequacy of Existing Regulatory Mechanisms
Federal Lands
Federal lands managed under the provisions of the NWFP comprise the
majority of the Applegate salamander's range. The NWFP acts to protect
salamanders and their habitat via a system of reserves and land
management guidelines that
[[Page 4405]]
dramatically reduce the likelihood of large-scale reduction of suitable
habitat.
Northwest Forest Plan Survey and Manage Mitigation Measure Standards
and Guidelines
The provisions and current status of the Survey and Manage Program
are described under Factor D for the Siskiyou Mountains salamander. The
Survey and Manage Program contains specific guidance for the Applegate
salamander DPS, requiring the identification of high-priority sites
that will be managed to provide a reasonable assurance of species
persistence. While the Survey and Manage Program currently provides
protection for the Applegate salamander DPS on Federal lands, we assume
for purposes of this finding that the Survey and Management Program is
eliminated for future projects on Federal lands and management of the
Applegate salamander DPS will be conducted under the USFS's Special
Status Species Program and the BLM's Sensitive Species Program. While
these programs do not specify protections for the Applegate salamander
DPS, they contain provisions for development of Conservation Strategies
that provide a reasonable assurance of species persistence.
Conservation Agreements
The final Conservation Strategy for the Siskiyou Mountains
Salamander, Northern Portion of the Range (Olson et al. 2007), is
currently being implemented by the USFS and BLM on Federal lands
occupied by the Applegate salamander DPS. The Conservation Strategy was
authored by four of the most-published scientific experts on this
species (D. Olson, D. Clayton, H. Welsh, and R. Nauman, among others),
and incorporates habitat modeling and risk assessment in the evaluation
of species persistence and distribution within the strategy area. The
Conservation Strategy is described in detail in the Background section
and under Factor D for the Siskiyou Mountains salamander, which is
incorporated by reference here. However, because of the limited nature
of the threats addressed by the Conservation Strategy, we did not rely
on it in determining whether listing the Applegate salamander is
warranted.
Western Oregon Plan Revisions
The BLM's proposed changes to its existing Resource Management
Plans through the WOPR contain provisions that have the potential to
increase timber harvesting within the range of the Applegate salamander
DPS (see Factor D for Siskiyou Mountains salamander). The WOPR proposal
affects only Federal lands administered by the BLM, which constitute
approximately 19 percent of the range of the Applegate salamander DPS.
The WOPR DEIS is currently in the public review period, and we cannot
at this time predict which alternative, including the no-action
alternative, will be selected or evaluate the potential effects to
Applegate salamander populations on BLM lands.
While the potential effects of possible RMP changes on the 19
percent of Applegate salamander DPS' range that occurs on BLM lands are
unknown, NWFP land-use allocations and management direction provides
substantial protection for the DPS and its habitat. If existing Federal
management for the Applegate salamander DPS is modified in the future,
the Service can consider any such changes in the context of the degree
and immediacy of potential threats to the DPS at that time.
Private Lands and State Regulations
Approximately 12 percent of the range of the Applegate salamander
DPS occurs on private lands located in Oregon, and 3 percent occurs on
private lands located in California. In Oregon, no regulatory
mechanisms exist to protect this DPS on private lands. In California,
the Siskiyou Mountains salamander (both Applegate and Grider
populations) is listed as a threatened species and receives substantial
protections pursuant to CESA. These protections include the requirement
of surveys prior to project implementation and prohibitions on timber
harvest in established buffers around occupied suitable habitat. There
is some uncertainty concerning the future of CESA protections for
Applegate salamander DPS populations on the small fraction of the DPS's
range that occurs in California (see Factor D for Siskiyou Mountains
salamander). Regardless of the future status of protections for the
Siskiyou Mountains salamander under CESA, those protections only apply
to 3 percent of the Applegate salamander DPS's range, and the potential
removal of these protections will not pose a significant threat to this
DPS.
As described under Factor A, we find that there is little evidence
to suggest that members of the Applegate salamander DPS are extirpated
by timber harvesting and other habitat disturbances. Research indicates
that populations of these salamanders persist following intensive
timber harvest and recover as vegetation is re-established. Less
intensive harvest practices appear to have little effect on
populations. Therefore, we find that the lack of regulatory protections
on state lands, a limited proportion of the range of the Applegate
salamander DPS, does not pose a threat to this genetic subunit in the
foreseeable future.
Summary of Factor D
Existing Federal regulations currently provide substantial
protection on Federal lands for the Applegate salamander DPS through
the NWFP land use categories and management provisions. For the
purposes of this finding, we assume that the NWFP's Survey and Manage
Program, which provides additional protection for the Applegate
salamander DPS, is eliminated for future projects on Federal lands
within the range of the DPS. Regulatory protection for this DPS will
consist of the Standards and Guidelines of the NWFP, other Federal land
management regulations, and the Special status Species programs, which
will continue to provide adequate protection for the DPS across the 85
percent of its range that occurs on Federal lands. While the
petitioners have cited the proposed WOPR as posing a significant
reduction to these protections (Greenwald and Curry 2007, p. 7), we
cannot at this time speculate about what impact, if any, the proposal,
if finalized in the future by BLM, may have on salamander populations
or their habitat.
We find that the current Federal regulations and land management
planning guidelines and the Special status Species programs provide
substantial protection for the DPS across the vast majority of its
range. The lack of regulatory mechanisms to protect the Applegate
salamander DPS on private lands in Oregon does not pose a substantial
threat because: (1) Private lands comprise a small portion of the DPS's
range and are distributed in small parcels interspersed among Federal
lands where management is more favorable and therefore, acts to
maintain redundancy, distribution, and connectivity among populations
within the mix of Federal and private lands; and (2) salamander
populations have been shown to persist in managed landscapes. While
there is some uncertainty concerning the future of CESA protections for
Applegate salamander DPS populations in California, the potential
removal of CESA protections will not pose a significant threat to the
DPS due to the very small percentage of the DPS's range that occurs in
the state and the interspersed pattern of private and state
[[Page 4406]]
lands. We, therefore, conclude that the Applegate salamander DPS is not
now, or in the foreseeable future, threatened by inadequate existing
regulatory mechanisms across its range.
Factor E: Other Natural or Manmade Factors Affecting the Continued
Existence of the Species
Other natural or manmade factors that could potentially affect the
persistence of the Applegate salamander DPS within all or significant
portion of its range are climate changes associated with global warming
and stochastic events, which are rare, chance events, such as epidemics
and large, severe wildfires.
Climate Change
The similarities in physiology, ecology, and habitat associations
between the Applegate salamander DPS and other members of the Siskiyou
Mountains salamander Complex, combined with the large scales at which
climate change studies are conducted, lead us to conclude that our
analysis of the potential effects of climate change under Factor E for
the Siskiyou Mountains salamander applies to the Applegate DPS as well.
Given its physiology, this species may be strongly affected by changes
to precipitation patterns. Although most of the available climate
models predict increases in average temperatures, models were
inconsistent with regard to future precipitation; increases in annual
precipitation and cloud cover are a plausible outcome and could act to
ameliorate negative impacts caused by increased temperatures. We are
unable to predict the potential effects of future climate change on the
Applegate salamander DPS at this time.
Stochastic Events
Like other members of the Siskiyou Mountains salamander Complex,
the Applegate salamander DPS occupies a relatively small geographic
range (248,870 ac (100,712 ha)) and exhibits limited dispersal
abilities. These traits act to increase a species' vulnerability to
stochastic (rare, chance) events such as epidemics or large, severe
fires because a single event can occur within all or a large portion of
the range, and individuals may be unable to escape the disturbance or
recolonize habitat following extirpation. However, as described in the
``Range and Distribution'' section and Factor A for the Siskiyou
Mountains salamander, current research suggests that Applegate
salamanders are in fact well-distributed within their range, that they
occur at high densities in some areas, and that they persist in areas
that have experienced disturbances. These traits act to decrease the
potential vulnerability conferred on this DPS by its small range. While
it may be reasonably expected that negative effects to abundance or
population structure may follow severe disturbances (as described under
Factor A for the Siskiyou Mountains salamander), there is no evidence
that they result in significant losses of populations.
A large wildfire that affects the majority of the range of the
Applegate salamander DPS is a plausible description of a significant
stochastic event. For example, 499,965 ac (202,329 ha) burned during
the 2002 Biscuit Fire in southwestern Oregon and northwestern
California. Approximately 44 percent of the area (219,985 ac (89,025
ha)) was severely burned (USDA and USDI 2004). In comparison, the
species range of the Applegate salamander DPS is 248,870 ac (100,712
ha). Although there is evidence that fire size and intensity may have
increased in the Klamath-Siskiyou region, large fires with mixed
severity are characteristic of the natural disturbance regime (Odion et
al. 2004, p. 933; Agee 1993, pp. 388-389) within which these
salamanders have evolved. The mosaic pattern of fire effects, combined
with the salamanders' ability to remain protected underground and
persist during postfire vegetation recovery, indicates that the threat
posed by this stochastic event is unlikely to result in large-scale
extirpation of populations.
Summary of Factor E
Because of the uncertain nature of climate change predictions,
particularly predictions of future precipitation patterns, we are
unable to evaluate the potential for climate change to impact Applegate
salamander DPS populations in the future. We find that, although
stochastic events such as large wildfires may occur within a large
portion of this salamanders' restricted range, Applegate salamanders
appear to persist following wildfires and other disturbances, to
recover as vegetation is re-established following disturbance, and have
adequate numbers of well-distributed populations throughout their range
to allow for persistence and viability of this DPS. We, therefore,
conclude that the Applegate salamander DPS is not now, or in the
foreseeable future, threatened by the individual or cumulative effects
of climate change or stochastic events such as epidemics or large,
severe wildfires.
Finding
We assessed the best available scientific and commercial
information regarding threats faced by the Applegate salamander DPS. We
have reviewed the petition, information available in our files, and
information submitted to us following our 90-day petition finding (72
FR 14750; March 29, 2007). We also consulted with recognized salamander
experts and Federal land managers, and arranged for researchers to
initiate field studies to assess the distribution of genetic entities
within the salamander complex, and demographic response of these
species to forest structure.
We find little support for the petitioners' claim that the
Applegate salamander DPS is threatened by habitat destruction caused by
timber harvesting and wildfire, and that existing regulatory mechanisms
are inadequate to protect the DPS. While the available information
suggests that Applegate salamanders may be positively associated with
older forest conditions, the majority of studies and available field
data show the species occupying a wide range of forest conditions,
including previously harvested areas. Recent research indicates that
even in severely disturbed habitats, the salamanders persist and
populations recover as vegetation is re-established over time. Less
intensive disturbances such as forest thinning and mixed-effects
wildfire appear to have minor or short-term impacts on salamander
abundance. There is no reliable evidence that indicates loss of
populations or curtailment of this DPS's range has occurred.
We acknowledge that intensive timber harvesting practices such as
clear-cutting may have short-term negative impacts on abundance and
population structure of Applegate salamanders. The extent and magnitude
of such practices, however, are severely limited by a number of
regulatory mechanisms and other factors operating within the
salamanders' range, as evidenced by the steep decline in timber harvest
levels on Federal lands that constitute 85 percent of the DPS's range.
Over the past 20 years, timber harvest levels, particularly of
intensive harvest methods, on Federal lands within the range of the
Applegate salamander have declined by over 90 percent. Levels of timber
harvesting are higher on private lands, which constitute only 15
percent of the DPS's range and occur as small parcels interspersed
among Federal lands. Due to the small proportion of the range
consisting of private lands, coupled with the ability of Applegate
salamanders to persist in managed
[[Page 4407]]
landscapes, we conclude that management activities on private lands do
not pose a substantial threat to this DPS.
There are a number of existing regulatory mechanisms that provide
protection for Applegate salamanders and their habitats. The system of
land use allocations and Standards and Guidelines of the NWFP act to
limit the amount and intensity of land management activities on Federal
lands, as evidenced by the dramatic decline in timber harvest levels
observed since the NWFP was implemented. The Survey and Manage
Mitigation Measure Standards and Guidelines are one aspect of the NWFP
that has provided protection specifically to occupied salamander
locations. However, we anticipate the elimination of the Survey and
Manage Guidelines within the range of the Applegate salamander DPS.
Federal land management agencies have implemented a Conservation
Strategy founded on the Survey and Management guidelines for this DPS,
to help provide for well-distributed, viable populations of Applegate
salamanders over the long term. The Conservation Strategy uses an
approach similar to that required by the Survey and Manage Program for
this DPS (i.e., identification of a network of high-priority salamander
populations for protection and management). However, because of the
limited nature of the threats addressed by the Conservation Strategy,
we did not rely on it in determining whether listing the Applegate
salamander DPS is warranted.
The BLM's proposal to revise WOPR on 19 percent of the Applegate
salamander DPS's range is in draft form and undergoing public review.
We cannot reliably predict the outcome of this process or what effect,
if any, any future changes to the WOPR might eventually have on
salamanders or their habitat. The NWFP land-use allocations, other
federal land management, and the special Status Species programs
constitute existing regulatory mechanisms that currently provide
substantial protection for the Applegate DPS and it habitat on Federal
lands and are anticipated to continue to provide such protection in the
foreseeable future. Should regulatory protections change in the future,
the Service can consider such changes in the context of the degree and
immediacy of potential threats to the Siskiyou Mountains salamander at
that time.
Populations of Applegate salamanders are well distributed, and
abundance within populations can be high. There are 440 known locations
for this DPS, and many areas supporting suitable habitat have not been
surveyed. These population characteristics, combined with the species'
apparent ability to persist and recover following habitat disturbance,
indicates that Applegate salamanders are resilient to stochastic events
such as wildfire. Our evaluation of climate change modeling for the
geographic area inhabited by the salamanders does not support the
contention that climate change poses a threat to Applegate salamanders.
While increases in average daily temperatures are reliably predicted
for the Klamath-Siskiyou region, predictions regarding timing and
amount of precipitation are inconsistent, precluding any meaningful
evaluation of future effects to these salamanders. It is not currently
possible to forecast the specific effects of future climate on
salamander populations.
Our evaluation of the five listing factors does not support the
contention that there are threats of sufficient imminence, intensity,
or magnitude as to cause substantial threats to the DPS, losses of
population distribution, or viability of the Applegate salamander DPS.
Therefore, we do not find that the Applegate salamander DPS is in
danger of extinction (endangered), nor is it likely to become
endangered within the foreseeable future (threatened) throughout its
range. Therefore listing the Applegate salamander DPS as threatened or
endangered under the Act is not warranted at this time.
Grider Salamander Distinct Population Segment
Factor A: The Present or Threatened Destruction, Modification, or
Curtailment of the Species' Habitat or Range
Our current knowledge of the habitat associations of the Grider
salamander DPS, and the potential effects of habitat perturbations such
as timber harvest and fire on this salamander, are based primarily on
research conducted across the range of the entire Siskiyou Mountains
salamander Complex. The members of the complex have similar
physiological and behavioral characteristics, and consequently similar
habitat associations. This conclusion is supported by Welsh et al.
(2007a, p. 31), who state that the genetic subunits of Siskiyou
Mountains salamander ``do little if anything to alter their basic eco-
physiological limits (e.g., Spotila 1972; Feder 1983) and consequent
similar environmental requirements imposed by the plethodontid life
form.'' We recognize that the range of the Grider salamander DPS is
roughly 40 percent of the area occupied by the entire Siskiyou
Mountains salamander, and that the relative magnitude of effects caused
by habitat perturbations may be greater at this smaller spatial scale.
We have incorporated these differences of scale into our analysis.
Given this caveat, we believe that the potential effects of timber
harvesting, fire, and other habitat perturbations on the Grider
salamander DPS are similar to those described previously for the
Siskiyou Mountains salamander. To avoid redundancy, these effects are
summarized below; details and citations may be found in the Factor A
analysis for Siskiyou Mountains salamander.
Effects of Timber Harvesting on the Grider Salamander DPS
Although rigorous research of the effects of timber harvesting on
Grider salamanders is lacking, the available evidence suggests that
intensive timber harvest practices such as clear-cutting have a short-
term (30 years) negative impact on abundance, age structure, and body
condition of these salamanders. However, it is also clear that the
salamanders frequently persist in intensively harvested areas, and that
populations recover as vegetation is re-established. Alternative timber
harvesting methods such as thinning and helicopter yarding have not
been shown to have negative effects on populations of this DPS.
Extent and Magnitude of Timber Harvesting Effects on the Grider
Salamander DPS
The extent and magnitude of potential effects caused by timber
harvesting are strongly limited by existing land management regulations
on the majority of the range of this DPS. Approximately 91 percent of
the range of the Grider salamander DPS consists of Federal lands
managed by the Klamath National Forest (KNF) under the provisions of
the NWFP. Approximately 73 percent of the range occurs within reserves
(Late-successional Reserves, Wilderness, Riparian Reserves) withdrawn
from scheduled timber harvesting; an additional 13 percent of the range
is within Matrix-retention areas where timber harvest is restricted.
Less than 5 percent of the Grider salamanders' range lies within the
Matrix-General Forest land allocation where intensive timber harvesting
is anticipated to occur.
Primarily as a result of implementation of the NWFP, the rate and
intensity of timber harvesting has declined substantially on Federal
lands within the range of the Grider salamander DPS. During the period
from 1979 to 1984, the KNF sold and removed an average of 238.2 million
[[Page 4408]]
board feet of timber per year; harvest levels declined to 187.8 million
board feet per year during 1985 to 1990, and fell to 15.9 million board
feet annually between 2000 and 2005; a decrease of roughly 93 percent
(USDA 2006a). The proportion of intensive timber management practices
such as clear-cutting and overstory removal has declined even more
abruptly; from an annual average of 3,733 ac (1,511 ha) per year from
1988 to 1991 to roughly 38 ac (15.4 ha) per year during 2000 to 2006
(USDA 2007b). We conclude that the land management regulations
responsible for this long-term declining trend in the rate and
intensity of timber harvesting greatly reduces the likelihood that a
substantial proportion of the Grider salamander DPS will be negatively
affected by intensive timber harvesting.
Less than 10 percent of the Grider salamander's range consists of
private timberlands where intensive timber harvesting practices such as
clear-cutting and shelterwood removal are likely to occur. Virtually
all of these lands are in California; only about 1 percent occurs in
Oregon. The majority of private lands within the range of the Grider
salamander DPS occur as small parcels (typically one square mile or
less) in a checkerboard pattern surrounded by Federal lands. Salamander
populations on private lands may be affected by timber harvesting but
are dispersed among populations on Federal lands where management is
more favorable and serves to effectively reduce the impacts of
intensive private land timber harvest practices and maintain
redundancy, distribution, and connectivity among Grider DPS
populations.
Wildfire
We assume that the potential effects of wildfire on the Grider
salamander DPS are similar to those described under Factor A for the
Siskiyou Mountains salamander. It is likely that intense, stand-
replacing fires reduce habitat quality for this salamander by reducing
overstory cover and consuming moss, duff and forest floor litter;
affecting the microclimate conditions. However, Siskiyou Mountains
salamanders appear to be behaviorally adapted to dry-season fires
because they are underground during summer and fall when most wildfires
occur. While it is likely that large-scale intense wildfires may
negatively impact some populations, at least in the short term,
populations appear to persist and recover as vegetation is re-
established after severe habitat disturbances. Fire regimes within the
Klamath-Siskiyou region are characterized by mixed-severity fires that
burn in a range of intensities, resulting in a mosaic of habitat
effects. Fire effects are frequently moderated on lower slopes with
northerly exposures and topographic conditions frequently associated
with salamander locations.
Direct Disturbance: Roads and Road Construction, Mining, and Rock
Quarrying
We assume that the effects of activities that physically alter the
talus substrates occupied by Grider salamanders are similar to those
described under Factor A for the Siskiyou Mountains salamander.
Although research to evaluate salamander response to physical
disturbance is lacking, it is reasonable to assume that these
activities likely reduce habitat quality or remove habitat. In
addition, some research suggests that forest roads may pose a barrier
to these salamanders, reducing dispersal and connectivity among
populations. We find that, while it may reasonably be expected that
crushing or removal of talus habitat during road construction, mining,
or rock quarrying could negatively affect Grider salamander
populations, these activities affect a very small area of the DPS
range. For this reason, Olson et al. (2007, p. 17) conclude that these
disturbances do not pose a primary threat to the species. Numerous
records exist of the salamanders occupying road cuts and sites with
historical mining activity, suggesting that these disturbances do not
eliminate populations. The rate of road construction, which is
typically associated with access for timber harvesting, has declined
significantly as timber harvest levels have dropped. Surface mining
rarely occurs within the range of the DPS, and rock quarrying consists
of a small number of sites encompassing an insignificant proportion of
the range (less than 100 ac (40.5 ha)).
Summary of Factor A
We find that, while the abundance and population structure of
Grider salamanders appear to suffer short-term negative effects from
intensive timber management practices such as clear-cutting, these
practices are severely restricted on Federal lands, which constitute
over 90 percent of the DPS's range. Less than five percent of the
Grider salamander's range lies within the Matrix-General Forest land
allocation where intensive timber harvesting is anticipated to occur.
Less intensive harvest practices appear to have relatively minor or
short-term impacts to salamander abundance, and the available evidence
suggests that salamander populations persist in a broad range of forest
habitat conditions and under different management practices.
The system of NWFP reserves and management guidelines in effect on
Federal lands, in combination with other Federal land management
direction and the Special Status Species programs, provide substantial
protection for Grider salamander habitat, dramatically reducing the
likelihood of large-scale reduction of suitable or occupied habitat due
to timber harvesting. Even without Survey and Manage protections, the
available evidence does not show that timber harvest practices on
Federal lands, either alone or in combination with other habitat
disturbing activities such as mining, road building or wildfire, have
reduced the habitat or range of this species or are likely to do so in
the foreseeable future.
Management practices on private timberlands may negatively affect
some populations of the Grider salamander DPS; however, due to the
patchy distribution of private lands within the larger matrix of
Federal lands, and the ability of these salamanders to persist in
managed habitats, we conclude that habitat modifications on this small
portion of the Grider salamander DPS's range do not constitute a
substantial threat to the DPS.
Wildfires are a naturally occurring disturbance factor in the
Klamath-Siskiyou region, and are expected to influence the abundance
and distribution of salamander habitats. However, the effects of most
wildfires on salamander habitat are temporary and populations appear to
recover as vegetation recovers. Wildfires typically burn in a mosaic
pattern of intensities, leaving a variety of habitat conditions for
salamanders within burned areas.
Grider salamander populations have been shown to exist in a range
of habitat conditions that have experienced timber harvesting,
wildfire, and other disturbances, and there is little evidence to
suggest that populations are extirpated followed the land management
activities such as thinning and salvage harvesting typically employed
on KNF lands. Intense disturbances such as clear-cutting are highly
limited by current land-use regulations, and along with rock quarrying
and road construction constitute a tiny fraction of the DPS's habitat.
Therefore, we conclude that the Grider salamander DPS is not now, or in
the foreseeable future, threatened by
[[Page 4409]]
destruction, modification, or curtailment across its range.
Factor B: Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
We are not aware of any information that indicates overutilization
for commercial, recreational, scientific, or educational purposes
threatens, now or in the foreseeable future, the Grider salamander DPS
across its range.
Factor C: Disease or Predation
Chytridiomycosis is a relatively recently described epidermal
infection of amphibians caused by the chytrid fungus Batrachochytrium
dendrobatidis. This fungus requires moisture for survival (Johnson and
Speare 2003, p. 922) and is therefore more likely to pose a threat to
aquatic amphibians than to terrestrial ones. As described for the
Siskiyou Mountains salamander, we do not anticipate that the Grider
salamander DPS will be exposed to this disease or that exposure would
lead to transmission through significant portions of its range. This
DPS is not associated with bodies of water, occurs in a
characteristically dry environment, is only active above ground for
brief and intermittent periods during the year, and appears to have
limited dispersal abilities. Given these restrictions, we believe that
the Grider salamander DPS is unlikely to be exposed to diseased water
or infected aquatic amphibians and, if infected, these salamanders are
unlikely to transmit the disease between populations.
The Service is not aware of any predators that potentially pose a
threat to the species. We therefore conclude that the Grider salamander
DPS is not now, or in the foreseeable future, threatened by disease or
predation across its range.
Factor D: Inadequacy of Existing Regulatory Mechanisms
Federal Lands
Existing Federal regulations currently provide substantial
protection on Federal lands for the Grider salamander DPS through the
NWFP land use allocations and their management provisions. The NWFP
management provisions and current status of the Survey and Manage
Program are described under Factor D for the Siskiyou Mountains
salamander. The Survey and Manage Program contains specific guidance
for the Grider salamander DPS, requiring surveys of potentially
suitable talus habitat and restricting management activities at
occupied salamander locations. For purposes of this finding, we assume
that NWFP's Survey and Manage Program is eliminated for future projects
on Federal lands within the range of the DPS.
Given the high proportion of KNF lands in reserved land allocations
(86 percent), the low rate of timber harvest, and the low intensity of
harvest practices typically employed by the KNF, we conclude that the
removal of Survey and Manage guidelines does not pose a substantial
threat to the species. Management of the Grider salamander DPS will be
conducted under the USFS's Sensitive Species Program, which does not
specify protections, but contains provisions for development of
conservation strategies that are anticipated to provide an additional
layer of security for the DPS.
Private Lands and State Regulations
The Siskiyou Mountains salamander is listed as a threatened species
in California and receives substantial protections pursuant to CESA.
These protections include the requirement of surveys prior to project
implementation and prohibitions on timber harvest in established
buffers around occupied suitable habitat (see Factor D for Siskiyou
Mountains salamander). The future of CESA protections for Grider
salamander populations on private timberlands is uncertain. However,
any future changes in the status of CESA protections for the Grider
salamander DPS would affect only nine percent of the range of the
Grider salamander DPS, and this area consists of small parcels
interspersed among Federal lands. This, combined with evidence that
Grider salamander populations persist in disturbed habitats, suggests
that the removal of CESA protections will not pose a substantial threat
to the species.
Summary of Factor D
The Grider salamander DPS receives substantial protection based on
the land allocations and Standards and Guidelines of the NWFP and KNF
Land and Resource Management Plan. Future protection of the Grider
salamander DPS will also occur through the USFS Sensitive Species
Program. The high proportion the DPS's range within reserved land
allocations, combined with the overall low rate and intensity of timber
harvest on Federal lands leads us to conclude that elimination of the
Survey and Manage guidelines does not pose a substantial threat to this
DPS. We find that the combination of Federal regulations and land
management planning guidelines provide adequate existing regulatory
mechanisms across the vast majority of the DPS's range.
The Grider salamander DPS also receives protection on private lands
in California under CESA. The uncertainty of future CESA protections
for Grider salamander populations on private lands does not pose a
substantial threat to the DPS because: (1) Private lands comprise a
small portion of the DPS's range and generally consist of small parcels
interspersed among Federal lands; and (2) salamander populations have
been shown to persist in managed landscapes. We therefore conclude that
the Grider salamander DPS is not now, or in the foreseeable future,
threatened by inadequate existing regulatory mechanisms.
Factor E: Other Natural or Manmade Factors Affecting the Continued
Existence of the Species
Other natural or manmade factors that may affect the persistence of
the Grider salamander DPS within all or significant portion of its
range are climate changes associated with global warming and stochastic
events, which are rare, chance events, such as epidemics and large,
severe wildfires.
Climate Change
Because the physiology, ecology, and habitat associations of the
Grider salamander DPS are similar to other members of the Siskiyou
Mountains salamander Complex, we conclude that our analysis of the
potential effects of climate change and stochastic events under Factor
E for the Siskiyou Mountains salamander applies to the Grider
salamander DPS as well. Most of the climate change models available for
the Pacific Northwest predicted increases in average temperatures;
however, models were inconsistent with regard to future precipitation.
Some models predicted significant increases in annual precipitation and
cloud cover, which could act to ameliorate any negative impacts caused
by increased temperatures. Given the inconsistency of climate change
predictions available to us, we are unable to predict the potential
effects of future climate change on the Grider salamander DPS at this
time.
Stochastic Events
The relatively small geographic range (174,285 ac (70,529 ha)) and
limited dispersal abilities of the Grider salamander DPS may increase
its vulnerability to stochastic (rare, chance) events such as epidemics
or large, severe fires because a single event can occur within all or a
large portion of the range, and individuals may be unable to escape the
disturbance or recolonize habitat following extirpation. The
[[Page 4410]]
petitioners claim that these salamanders are rare, patchily
distributed, and easily extirpated by disturbances, making them highly
vulnerable to extinction (Greenwald and Curry 2007, p. 1). However, as
described under ``Range and Distribution'' and Factor A for the
Siskiyou Mountains salamander, current research suggests that Grider
salamanders are in fact well-distributed within their range, that they
occur at high densities in some areas, and that they persist in areas
that have experienced disturbances. These traits act to decrease the
potential vulnerability conferred on this DPS by its small range. While
it may be reasonably expected that negative effects to abundance or
population structure may follow severe disturbances (as described under
Factor A for the Siskiyou Mountains salamander), there is no evidence
that they result in significant losses of populations.
A large wildfire that affects the majority of the range of the
Grider salamander DPS is a plausible description of a significant
stochastic event. For example, 499,965 ac (202,329 ha) burned during
the 2002 Biscuit Fire in southwestern Oregon and northwestern
California. Approximately 44 percent of the area (219,985 ac (89,025
ha)) was severely burned (USDA and USDI 2004). In comparison, the
species range of the Grider salamander is 174,285 ac (70,529 ha).
Although there is evidence that fire size and intensity may have
increased in the Klamath-Siskiyou region, large fires with mixed
severity are characteristic of the natural disturbance regime (Odion et
al. 2004, p. 933; Agee 1993, pp. 388-389) within which these
salamanders have evolved. The mosaic pattern of fire effects, combined
with the salamanders' ability to remain protected underground and
persist during postfire vegetation recovery, indicates that the threat
posed by this stochastic event is unlikely to result in large-scale
extirpation of populations.
Summary of Factor E
Because of the uncertain nature of climate change predictions,
particularly predictions of future precipitation patterns, we are
unable to evaluate the potential for climate change to impact Grider
salamander populations in the foreseeable future. We find that,
although stochastic events such as large wildfires may occur within a
large portion of this salamanders' restricted range, Grider salamanders
appear to persist following wildfires and other disturbances, to
recover as vegetation is re-established following disturbance, and have
adequate numbers of well-distributed populations throughout their range
to allow for persistence and viability of this DPS. We therefore
conclude that the Grider salamander DPS is not now, or in the
foreseeable future, threatened by the individual or cumulative effects
of climate change or stochastic events such as epidemics or large,
severe wildfires.
Finding
We assessed the best available scientific and commercial
information regarding threats faced by the Grider salamander DPS. We
have reviewed the petition, information available in our files, and
information submitted to us following our 90-day petition finding (72
FR 14750; March 29, 2007). We also consulted with recognized salamander
experts and Federal land managers, and arranged for researchers to
initiate field studies to assess the distribution of genetic entities
within the salamander complex, and demographic response of these
species to forest structure.
We find little support for the petitioners' claim that the Grider
salamander DPS is threatened by habitat destruction caused by timber
harvesting and wildfire, and that existing regulatory mechanisms are
inadequate to protect the DPS from this habitat loss. While the
available information suggests that Grider salamanders may be
positively associated with older forest conditions, the majority of
studies and available field data show the species occupying a wide
range of forest conditions, including previously harvested areas.
Recent research indicates that even in severely disturbed habitats, the
salamanders persist and populations recover as vegetation is re-
established over time. Less intensive disturbances such as forest
thinning and mixed-effects wildfire appear to have minor or short-term
impacts on salamander abundance. There is no reliable evidence that
indicates that loss of populations or curtailment of this DPS's range
has occurred.
We acknowledge that intensive timber harvesting practices such as
clear-cutting may have short-term negative impacts on abundance and
population structure of Grider salamanders. The extent and magnitude of
such practices, however, are severely limited by a number of regulatory
mechanisms and other factors operating within the salamanders' range,
as evidenced by the steep decline in timber harvest levels on Federal
lands that constitute 91 percent of the DPS' range. Over the past 20
years, timber harvest levels, particularly of intensive harvest
methods, on Federal lands within the range of the Grider salamander
have declined by over 93 percent. Levels of timber harvesting are
higher on private lands, which constitute only nine percent of the
DPS's range and occur as small parcels interspersed among Federal
lands. Due to the small proportion of the DPS's range that consists of
private lands, the scattered small size of private land parcels, and
the ability of Grider salamanders to persist in managed landscapes, we
conclude that management activities on private lands do not pose a
substantial threat to this DPS.
There are a number of existing regulatory mechanisms that provide
protection for the Grider salamanders and its habitat. The system of
land use allocations under the NWFP act to limit the amount and
intensity of land management activities on Federal lands, as evidenced
by the dramatic decline in timber harvest levels observed since the
NWFP was implemented. The Survey and Manage Mitigation Measure
Standards and Guidelines are one aspect of the NWFP that, in the past,
has provided protection specifically to occupied salamander locations.
While the Survey and Manage Program has been eliminated for future
projects on Federal lands, we find that existing land management
regulations are adequate given the low degree of threat posed by land
management activities.
Populations of Grider salamanders are well distributed, and
abundance within populations can be high. There are 76 known locations
for this DPS, and many areas supporting suitable habitat have not been
surveyed. These population characteristics, combined with the species'
apparent ability to persist and recover following habitat disturbance,
indicates that Grider salamanders are resilient to stochastic events
such as wildfire. Our evaluation of climate change modeling for the
geographic area inhabited by the salamanders does not support the
contention that climate change poses a threat to Grider salamanders.
While increases in average daily temperatures are reliably predicted
for the Klamath-Siskiyou region, predictions regarding timing and
amount of precipitation are inconsistent, precluding any meaningful
evaluation of future effects to these salamanders. It is not currently
possible to forecast the specific effects of future climate on
salamander populations.
Our evaluation of the five listing factors does not support the
contention that there are threats of sufficient imminence, intensity,
or magnitude as to cause substantial losses of population distribution
or viability of the Grider salamander DPS. Therefore, we do not
[[Page 4411]]
find that the Grider salamander DPS is in danger of extinction
(endangered), nor is it likely to become endangered within the
foreseeable future (threatened) throughout its range. Therefore listing
the Grider salamander DPS as threatened or endangered under the Act is
not warranted at this time.
Scott Bar Salamander
Summary of Factors Affecting the Species
Factor A: The Present or Threatened Destruction, Modification, or
Curtailment of the Species' Habitat or Range
The Service believes that the potential effects of habitat
perturbations such as timber harvest and fire on the Scott Bar
salamander are the same as those previously described for the entire
Siskiyou Mountains salamander Complex. This conclusion is based on: (1)
Our understanding of the behavior, physiology, and habitat associations
of the Scott Bar salamander based primarily on research conducted
across the range of the entire Siskiyou Mountains salamander Complex;
and (2) available information which indicates that members of the
complex have similar physiological and behavioral characteristics, and
consequently similar habitat associations (Welsh et al. 2007a, p. 31).
Because the range of the Scott Bar salamander is roughly 32 percent of
the area occupied by the Siskiyou Mountains salamander, the relative
magnitude of effects caused by habitat perturbations may be greater at
this smaller spatial scale. Despite differences in scale, we believe
that the potential effects of timber harvesting, fire, and other
habitat perturbations on the Scott Bar salamander are the same as those
described previously for the Siskiyou Mountains salamander. To avoid
redundancy, these effects are summarized below; further detail and
citations may be found in the Factor A analysis for Siskiyou Mountains
salamander.
Effects of Timber Harvesting on the Scott Bar Salamander
Our evaluation of recent research results and survey information
indicates that, while abundance of Scott Bar salamanders may be greater
at sites with dense, mature forest cover, this species also occupies a
wide range of forest age and density conditions. Intensive timber
harvesting practices such as clear-cutting likely have negative effects
on habitat quality and subsequent abundance and population structure of
salamanders. However, recent research suggests that Scott Bar
salamanders persist in disturbed sites and their populations recover as
vegetation is re-established and habitat conditions improve (Welsh et
al. 2007b).
Roughly 40 percent of known Scott Bar salamander locations occur on
private timberlands where intensive timber management has been
conducted for decades. Farber (2007a, p. 3) evaluated population
structure and habitat characteristics at all Scott Bar salamander sites
known to be occupied on and adjacent to Timber Products Company (TPC)
lands. Ninety-four percent of the sites exhibited evidence of at least
one habitat disturbance such as roads, logging activity, wildfire, and
mining; 53 percent had evidence of recent or historic timber harvest.
None of the salamander sites were in old-growth or late-seral habitat;
all were in relatively young forests and over 50 percent occurred in
stands with open canopies. At 26 sites on TPC lands where a minimum of
two surveys were conducted, 96 percent supported adult salamanders, and
65 percent exhibited all life stages (adults, subadults, and
juveniles); gravid females were detected at 54 percent of sites. While
these results cannot be inferred to the entire species' range, they
clearly suggest that Scott Bar salamander populations persist and
appear to be viable within the range of habitat conditions found on
managed timberlands.
Extent and Magnitude of Timber Harvesting Effects on the Scott Bar
Salamander
Existing land management regulations place substantial limits on
the extent and magnitude of potential effects caused by timber
harvesting on populations of Scott Bar salamanders. Approximately 78
percent of the Scott Bar salamanders' range consists of Federal lands
managed by the KNF under the provisions of the NWFP. Approximately 51
percent of the range occurs within reserves (Late-successional
Reserves, Wilderness, and Riparian Reserves) withdrawn from scheduled
timber harvesting; an additional 19 percent of the range is within
Matrix-Retention areas where timber harvest is restricted. Only about
eight percent of the Scott Bar salamanders' range lies within the
Matrix-General Forest land allocation where intensive timber harvesting
is anticipated to occur.
The rate and intensity of timber harvesting has declined
substantially on Federal lands within the range of the Scott Bar
salamander, primarily due to NWFP provisions. The amount of timber sold
and removed on the Klamath National Forest declined by roughly 93
percent between 1984 and 2005, from an average of 238.2 million board
feet of timber per year in 1979 to 1984, to 15.9 million board feet
annually between 2000 and 2005 (USDA 2006a). The proportion of
intensive timber management practices such as clear-cutting and
overstory removal has also declined sharply, from an annual average of
3,733 ac (1,511 ha) per year from 1988 to 1991, to roughly 38 ac (15.4
ha) per year during 2000 to 2006 (USDA 2007b). We conclude that the
land management regulations responsible for this long-term declining
trend in the rate and intensity of timber harvesting greatly reduces
the likelihood that a substantial proportion of the Scott Bar
salamander will be affected by intensive timber harvesting.
Private timberlands comprise 22 percent of the range of the Scott
Bar salamander. State of California regulations under the California
Endangered Species Act currently protect Scott Bar salamanders on
private lands by requiring surveys and prohibiting habitat modification
at occupied sites, timber harvesting, and other habitat disturbances.
Private timberlands within the range of the Scott Bar salamander
occur as small (one square mile) parcels distributed in a checkerboard
pattern surrounded by KNF lands. This pattern acts to maintain the
distribution of, and connectivity among, salamander populations at
larger spatial scales, subsequently reducing the overall impact of
habitat losses on private lands. Salamander populations occupying the
private portions of this landscape pattern may experience fluctuations
in the amount or quality of habitat through time but likely receive
demographic support from adjacent populations on Federal lands where
management is more favorable.
Although the rate and intensity of timber harvest is greater on
privately owned timberlands within the range of the Scott Bar
salamander, not all private lands are expected to receive intensive
treatments. Timber Products Company, the primary industrial landowner
within the species' range, estimates that roughly 31 percent of the
company's land base within the range of the Scott Bar salamander in
Siskiyou County consists of land unsuitable for harvest (e.g., montane
hardwoods, watercourse protection zones, rock outcrops). On the
remaining 69 percent, 31 percent of projected timber harvest
prescriptions consist of less-intensive harvest prescriptions such as
thinning and selection, and 69 percent are more intensive treatments
such as clear-cut, shelterwood removal, and seed tree
[[Page 4412]]
harvest (Farber 2007c); suggesting that about 50 percent of TPC lands
are anticipated to receive intensive harvesting. Of the 25 Scott Bar
salamander locations currently known on TPC lands, 4 (16 percent) occur
in riparian areas where timber harvest is restricted by State
regulations, and 7 (28 percent) are located in previously harvested
areas where additional timber harvesting is not anticipated over the
next 20 to 30 years (Farber 2007b, pp. 1-2). This information, combined
with data indicating that salamander populations persist within managed
timberlands, further suggests that even in the absence of State
protections for this species, intensive timber harvest would not be
expected to impact a majority of populations within the 22 percent of
the species' range that occurs on private lands or pose a substantial
threat to the species.
Wildfire
Based on the best scientific information available, we believe the
potential effects of wildfire on the Scott Bar salamander are similar
to those described previously for the Siskiyou Mountains salamander.
Fire regimes within the Klamath-Siskiyou region are characterized by
mixed-severity fires that burn in a range of intensities, resulting in
a mosaic of habitat effects at both fine and landscape-level spatial
scales. Fire effects are frequently moderated on lower slopes with
northerly exposures, topographic conditions frequently associated with
salamander locations. Intense, stand-replacing fires likely reduce
habitat quality for these salamanders by reducing overstory cover and
consuming moss, duff, and forest floor litter, thereby modifying the
microclimate conditions. It is likely that large-scale intense
wildfires may negatively affect some populations, at least in the short
term, but the degree to which more typical mixed-severity wildfires
affect the viability of salamander populations is unknown. However,
Scott Bar salamanders appear to be behaviorally adapted to dry-season
fires because they are underground during summer and fall when most
wildfires occur. Populations appear to persist and recover as
vegetation is re-established after severe habitat disturbances (Bull et
al. 2006, p. 24; Welsh et al. 2007b).
Direct Disturbance: Roads and Road Construction, Mining, and Rock
Quarrying
As described under Factor A for the Siskiyou Mountains salamander,
activities that physically alter the talus substrates occupied by the
Scott Bar salamander have the potential to reduce habitat quality or
remove habitat. While some of these activities such as rock quarrying
may completely remove habitat, evidence suggests that salamander
populations continue to occupy areas that show evidence of previous
mining and road construction. In particular, numerous Scott Bar
salamander locations occur in road cuts where rock substrate has been
exposed. Although the ease of accessing and surveying such sites may
influence the probability of detecting salamanders, the frequent
presence of salamanders in road cuts suggests that this species can
persist in or recolonize disturbed substrates. Despite these potential
effects, road construction and rock quarrying are extremely limited in
spatial extent, affecting a very small fraction of the salamander's
range, and are not considered a substantial threat to these salamanders
(Olson et al. 2007, p. 17).
Summary of Factor A
The abundance and population structure of Scott Bar salamanders
appear to exhibit short-term negative effects from intensive timber
management practices such as clear-cutting, but these practices are
severely restricted on Federal lands, which constitute 78 percent of
the species' range. Less intensive harvest practices appear to have
relatively minor or short-term impacts to salamander abundance, and the
available evidence suggests that salamander populations persist in a
broad range of forest habitat conditions and under different management
practices.
Scott Bar salamander populations receive substantial protection
from the system of NWFP reserves and management guidelines in effect on
Federal lands, in combination with other land management direction
(e.g. Roadless Areas, retention areas) and the Special Status Species
programs, dramatically reducing the likelihood of substantial negative
impacts to suitable or occupied habitat due to timber harvesting. Even
without Survey and Manage protections, the available evidence does not
show that timber harvest practices on Federal lands, either alone or in
combination with other habitat disturbing activities such as mining,
road building or wildfire, have reduced the habitat or range of this
species or are likely to do so in the foreseeable future.
Although timber harvest levels on private timberlands are greater
than on Federal lands, current State regulations restrict management
activities at occupied Scott Bar salamander locations. Known salamander
locations on private timberlands occur in a variety of habitat
conditions, including previously harvested areas and naturally open
sites, demonstrating that populations persist in these managed
landscapes. The dispersed pattern of private land parcels among Federal
lands acts to maintain well-distributed populations, and may allow
demographic support between adjacent populations.
Wildfires are a naturally-occurring disturbance factor in the
Klamath-Siskiyou region, and are expected to influence the quality,
abundance and distribution of Scott Bar salamander habitat. However,
the effects of most wildfires on salamander habitat appear to be
temporary and populations recover as vegetation is re-established on
burned areas. Wildfires typically burn in a mosaic pattern of
intensities, leaving a variety of habitat conditions for salamanders
within burned areas.
In summary, Scott Bar salamander populations have been shown to
exist in a range of habitat conditions that have experienced timber
harvesting, wildfire, and other disturbances, and there is evidence
suggesting that populations persist and recover following habitat
disturbances. Current land-use regulations, including State regulations
protecting the Scott Bar salamander on private timberlands, strongly
limit intense disturbances such as clear-cutting, rock quarrying, and
road construction. Therefore, we conclude that the Scott Bar salamander
is not now, or in the foreseeable future, threatened by destruction,
modification, or curtailment across its range.
Factor B: Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
We are not aware of any information that indicates overutilization
for commercial, recreational, scientific, or educational purposes
threatens the Scott Bar salamander, now or in the foreseeable future,
across its range.
Factor C: Disease or Predation
Chytridiomycosis is a relatively recently described epidermal
infection of amphibians caused by the chytrid fungus Batrachochytrium
dendrobatidis. This fungus requires moisture for survival (Johnson and
Speare 2003, p. 922) and is therefore more likely to pose a threat to
aquatic amphibians than to terrestrial ones. As described for the
Siskiyou Mountains salamander, we do not anticipate that the Scott Bar
salamander will be exposed to this disease or that exposure would lead
to
[[Page 4413]]
transmission through significant portions of its range. This species is
not associated with bodies of water, occurs in a characteristically dry
environment, is only active above ground for brief and intermittent
periods during the year, and appears to have limited dispersal
abilities. Given these restrictions, we believe that the Scott Bar
salamander is unlikely to be exposed to diseased water or infected
aquatic amphibians and, if infected, is unlikely to transmit the
disease between populations.
The Service is not aware of any predators that potentially pose a
threat to the species. We therefore conclude that the Scott Bar
salamander is not now, or in the foreseeable future, threatened by
disease or predation across its range.
Factor D: Inadequacy of Existing Regulatory Mechanisms
Federal Lands
Existing Federal regulations currently provide substantial
protection on Federal lands for the Scott Bar salamander through the
NWFP land use allocations and their management requirements. The
provisions and current status of the Survey and Manage Program are
described under Factor D for the Siskiyou Mountains salamander. The KNF
extended Survey and Manage Program guidance to the Scott Bar
salamander, since this species cannot be easily distinguished from the
Siskiyou Mountains salamander in the field (USDA 2006b, p. 2).
The Survey and Manage Program requires surveys of potentially
suitable talus habitat and restricting management activities at
occupied Scott Bar salamander sites. For purposes of this finding, we
assume that NWFP's Survey and Manage Program is eliminated for future
projects on Federal lands within the range of the Scott Bar salamander.
Given the high proportion of the species range in reserved land
allocations (70 percent), the low rate of timber harvest, and the low
intensity of harvest practices typically employed by the KNF, we
conclude that the removal of Survey and Manage guidelines will not
constitute a substantial threat to the species. Management of the Scott
Bar salamander will be conducted under the USFS's Sensitive Species
Program, which does not specify protections for the Scott Bar
salamander but contains provisions for development of conservation
strategies that are anticipated to provide an additional layer of
security for the species.
The low proportion of KNF lands in land allocations where intensive
timber harvest is anticipated to occur (8 percent), combined with the
low degree and immediacy of potential threats to the Scott Bar
salamander, lead us to conclude that existing regulatory mechanisms are
adequate to maintain the viability of the Scott Bar salamander on
Federal lands throughout the species' range.
Private Lands and State Regulations
In July 2005, CDFG described the Scott Bar salamander as a ``newly
discovered species from what was part of the range of Plethodon
stormi'' (CDFG 2005, p. 31). Based on this change of taxonomic status,
CDFG took the position that the Siskiyou Mountains salamander
populations now recognized as Scott Bar salamanders were no longer
protected under CESA. That position was successfully challenged by
three environmental organizations in state court (Environmental
Protection Information Center v. California Department of Fish and
Game, (No. CPF-06-506585)). The court concluded that, ``[b]y virtue of
its having been accorded protection as a subgroup of a listed,
protected species, the Scott Bar salamander's protection under the
California Endangered Species Act cannot be withdrawn by the California
Department of Fish and Game without action first being taken by the
California Fish and Game Commission.'' On October 3, 2006, the
California Fish and Game Commission received a petition to list the
Scott Bar salamander under CESA. The Commission rejected the petition
due to the protections already provided the species under CESA.
The Scott Bar salamander is recognized by the Commission as
protected under CESA as a sub-group or sub-population of the listed
Siskiyou Mountains salamander (Cal. Code Regs. tit. 14, Sec. 670.5,
subd. (b)(3)(A).). However, the California Office of Administrative Law
recently rejected for procedural reasons a formal effort by the
Commission to recognize the protected status of the Scott Bar
salamander under CESA in State regulations (Cal. Reg. Notice Register
2007, No. 28-Z, p. 1191). The Scott Bar salamander, therefore, is not
specifically listed under CESA, but retains the same protections
afforded the Siskiyou Mountains salamander. The Service is not aware of
any other formal action by the Commission to recognize the protected
status of Scott Bar salamander under CESA.
The CDFG petition to delist the Siskiyou Mountains salamander does
not include the historic portion of this species' range known to be
occupied by the Scott Bar salamander. Therefore, the Service believes
that regardless of the California Fish and Game Commission's decision
on whether to delist the Siskiyou Mountains salamander, current State
protections for the Scott Bar salamander will remain in effect until a
formal rule-making process to remove these protections is undertaken.
To our knowledge, there is no formal process currently underway to
remove protections for the Scott Bar salamander.
We recognize the uncertainty surrounding the future of State
protections for Scott Bar salamanders on private lands and have
evaluated the threat potentially posed by timber harvesting on private
lands if protections were absent. As described under Factor A, we find
that there is little evidence to suggest that timber harvesting on
private lands threatens Scott Bar salamander populations because: (1)
Numerous populations are currently known to occur in a variety of
managed habitat conditions on private timberlands; (2) research
indicates that populations of these salamanders persist following
intensive timber harvest and recover as vegetation is re-established,
and less intensive harvest practices appear to have minor or short-term
effects on salamander abundance; and (3) private lands constitute only
22 percent of the species' range, and are distributed in a dispersed
pattern among Federal lands where conditions are more favorable and
thus acts to maintain the distribution of, and connectivity among,
salamander populations at larger spatial scales and reduce the impacts
of intensive timber harvest on adjacent private lands. Therefore, we
find that in the event that State protections for the Scott Bar
salamander are removed, the lack of regulatory protections on private
lands would not pose a substantial threat to this species in the
foreseeable future.
Summary of Factor D
The Scott Bar salamander receives substantial protection based on
the land allocations and Standards and Guidelines of the NWFP and KNF
Land and Resource Management Plan. Future protection of the Scott Bar
salamander will likely also occur through the USFS Sensitive Species
Program. The high proportion the species' range within reserved land
allocations, combined with the overall low rate and intensity of timber
harvest on Federal lands leads us to conclude that elimination of the
Survey and Manage guidelines does not pose a substantial threat to this
species. We find that the combination of Federal regulations and land
management planning guidelines provide adequate
[[Page 4414]]
existing regulatory mechanisms across the vast majority of the species'
range.
The Scott Bar salamander also receives protection on private lands
in California under CESA. While there presently is no effort underway
to remove State protections for the Scott Bar salamander, the continued
protection of the species under CESA for the foreseeable future is not
certain. However, we find that the uncertain future of CESA protections
for Scott Bar salamander populations on private lands does not pose a
substantial threat because: (1) Private lands comprise a small portion
of the species' range and are distributed in small parcels interspersed
among Federal lands; and (2) salamander populations have been shown to
persist in managed landscapes. We therefore conclude that the Scott Bar
salamander is not now, or in the foreseeable future, threatened by
inadequate regulatory mechanisms.
Factor E: Other Natural or Manmade Factors Affecting the Continued
Existence of the Species
Other natural or manmade factors that may affect the persistence of
the Scott Bar salamander across its range are climate changes
associated with global warming and stochastic events, which are rare,
chance events such as epidemics and large, severe wildfires.
Climate Change
The similarities in physiology, ecology, and habitat associations
between the Scott Bar salamander and other members of the Siskiyou
Mountains salamander Complex, combined with the large scales at which
climate change studies are conducted, lead us to conclude that our
analysis of the potential effects of climate change under Factor E for
the Siskiyou Mountains salamander applies to the Scott Bar salamander
as well. Given its physiology, this species may be strongly affected by
changes to precipitation patterns. Although most of the available
climate models predict increases in average temperatures, models were
inconsistent with regard to future precipitation; increases in annual
precipitation and cloud cover are a plausible outcome and could act to
ameliorate any negative impacts caused by increased temperatures. We
are unable to predict the potential effects of future climate change on
the Scott Bar salamander at this time.
Stochastic Events
The Scott Bar salamander is an endemic species with a relatively
small geographic range (136,740 ac (55,335 ha)) and limited dispersal
abilities. These traits may increase its vulnerability to stochastic
(rare, chance) events such as epidemics or large, severe fires because
a single event can occur within all or a large portion of the range,
and individuals may be unable to escape the disturbance or recolonize
habitat following extirpation. The petitioners claim that these
salamanders are rare, patchily distributed, and easily extirpated by
disturbances, making them highly vulnerable to extinction (Greenwald
and Curry 2007, p. 1). However, current research suggests that Scott
Bar salamanders are in fact well-distributed within their range, that
they occur at high densities in some areas, and that populations
persist in managed landscapes (see ``Range and Distribution'' and
Factor A for the Siskiyou Mountains salamander). These traits act to
decrease the potential vulnerability conferred on this species by its
small range. Severe disturbances such as clear-cutting or intense
wildfires may result in negative effects to abundance or population
structure of this species (as described under Factor A for the Siskiyou
Mountains salamander), but there is no evidence that they result in
significant losses of populations, and populations appear to recover
over time.
Although there is evidence that fire size and intensity may have
increased in the Klamath-Siskiyou region, large fires with mixed
severity are characteristic of the natural disturbance regime (Odion et
al. 2004, p. 933; Agee 1993, pp. 388-389) within which these
salamanders have evolved. However, a large wildfire that affects the
majority of the range of the Scott Bar salamander is a plausible
description of a significant stochastic event. Large fires such as the
2002 Biscuit Fire in southern Oregon may encompass an area similar to
or larger than the range of this species. This does not, however,
demonstrate that a fire of this magnitude is likely to threaten the
Scott Bar salamander in the foreseeable future. The diverse topography
and patchy distribution of habitats within the salamanders' range
suggests that a large fire would be unlikely to have homogeneous
effects at a large scale. The resulting mosaic pattern of fire effects,
combined with the salamanders' ability to remain protected underground
and persist during postfire vegetation recovery, indicates that the
threat posed by such a stochastic event would be unlikely to result in
large-scale extirpation of populations.
Summary of Factor E
The uncertain nature of climate change predictions, particularly
predictions of future precipitation patterns, precludes a meaningful
evaluation of potential impacts to Scott Bar salamander populations
resulting from future climate conditions. We find that, although
stochastic events such as large wildfires may occur within a large
portion of this salamanders' restricted range, Scott Bar salamanders
appear to persist following wildfires and other disturbances, to
recover as vegetation is re-established following disturbance, and have
adequate numbers of well-distributed populations throughout their range
to allow for persistence and viability of this species. We therefore
conclude that the Scott Bar salamander is not now, or in the
foreseeable future, threatened by the individual or cumulative effects
of climate change or stochastic events such as epidemics or large,
severe wildfires.
Finding
We assessed the best available scientific and commercial
information regarding threats faced by the Scott Bar salamander. We
have reviewed the petition, information available in our files, and
information submitted to us following our 90-day petition finding (72
FR 14750; March 29, 2007). We also consulted with recognized salamander
experts, and Federal and private land managers, and arranged for
researchers to initiate field studies to assess the distribution of
genetic entities within the salamander complex and demographic response
of these species to forest structure and management practices.
We find little support for the petitioners' claim that the Scott
Bar salamander is threatened by habitat destruction caused by timber
harvesting and wildfire, and that existing regulatory mechanisms are
inadequate to protect the species. While the available information
suggests that Scott Bar salamanders may be positively associated with
older forest conditions, the majority of studies and available field
data show the species occupying a wide range of forest conditions,
including previously harvested areas. Recent research indicates that
these salamanders persist and populations recover as vegetation is re-
established in intensively disturbed habitats. Less-intensive
disturbances such as forest thinning and mixed-effects wildfire appear
to have minor or short-term impacts on salamander abundance. There is
no reliable evidence that indicates loss of populations or curtailment
of this species' range has occurred.
We acknowledge that the abundance and population structure of Scott
Bar salamander populations may be
[[Page 4415]]
negatively affected by intensive timber harvesting practices such as
clear-cutting. The extent and magnitude of such practices, however, are
severely limited by a number of regulatory mechanisms and other factors
operating within the salamanders' range, as evidenced by the steep
decline in timber harvest levels on Federal lands that constitute 78
percent of the species' range. Although levels of timber harvesting are
higher on private timberlands, such lands constitute only 22 percent of
the species' range and occur as small parcels interspersed among
Federal lands. The small proportion of the range consisting of private
lands, coupled with the ability of Scott Bar salamanders to persist in
managed landscapes, leads us to conclude that forest management
activities on Federal or private lands do not pose a substantial threat
to this species.
Several complementary regulatory mechanisms provide protection for
Scott Bar salamanders and their habitats. On Federal lands constituting
78 percent of the species' range, the NWFP's system of land use
allocations and management guidelines impose substantial limitations on
the amount and intensity of land management activities, as evidenced by
the dramatic decline in timber harvest levels observed since the NWFP
was implemented. For this reason, the elimination of the Survey and
Manage Program, which has provided protection specifically to occupied
salamander locations, does not pose a substantial threat to the
species.
As a species, the Scott Bar salamander exhibits several
characteristics that, when combined, suggest that Scott Bar salamanders
are resilient to stochastic events such as large wildfires. Populations
of Scott Bar salamanders are distributed among several watersheds, and
abundance within populations can be high. There are 115 known locations
within the estimated range of this species, and the majority of
suitable habitat has not been surveyed. These population
characteristics, combined with the species' apparent ability to persist
and recover following habitat disturbance, acts to reduce any potential
threat posed by stochastic events. Our evaluation of climate change
modeling for the geographic area inhabited by the salamanders does not
support the contention that future climate poses a threat to Scott Bar
salamanders, because it is not currently possible to forecast future
precipitation regimes.
Our evaluation of the five listing factors does not support the
contention that there are threats of sufficient imminence, intensity,
or magnitude as to cause substantial losses of population distribution
or viability of the Scott Bar salamander. Therefore, we do not find
that the Scott Bar salamander is in danger of extinction (endangered),
nor is it likely to become endangered within the foreseeable future
(threatened) across its range. Therefore, listing the species as
threatened or endangered under the Act is not warranted at this time.
Under the Services' DPS policy, (61 FR 4722, February 7, 1996)
three elements are considered in the decision concerning the
establishment and classification of a possible DPS. These are applied
similarly for additions to the Lists of Endangered and Threatened
Wildlife and Plants. These elements include: (1) The discreteness of a
population in relation to the remainder of the species to which it
belongs; (2) the significance of the population segment to the species
to which it belongs; and (3) the population segment's conservation
status in relation to the Act's standards for listing, delisting, or
reclassification (i.e., is the population segment endangered or
threatened). We are not aware of any information that would lead us to
conclude that the Scott Bar salamander is comprised of population
segments that are either discrete or significant. Therefore, we have
not analyzed the Scott Bar salamander under the Services' DPS policy.
Significant Portion of the Range Analysis
Having determined that the Siskiyou Mountains salamander, the
Applegate salamander DPS of Siskiyou Mountains salamander, the Grider
DPS of Siskiyou Mountains salamander, and the Scott Bar salamander do
not meet the definition of a threatened or endangered species, we must
next consider whether there are any significant portions of their
ranges where the species or DPS is in danger of extinction or is likely
to become endangered in the foreseeable future.
On March 16, 2007, a formal opinion was issued by the Solicitor of
the Department of the Interior, ``The Meaning of `In Danger of
Extinction Throughout All or a Significant Portion of Its Range' ''
(USDI 2007c). We have summarized our interpretation of that opinion and
the underlying statutory language below. A portion of a species' range
(in this case, ``species'' refers to the Siskiyou Mountains salamander,
the Scott Bar salamander, and both Siskiyou Mountains salamander DPSs)
is significant if it is part of the current range of the species and it
contributes substantially to the representation, resiliency, or
redundancy of the species. The contribution must be at a level such
that its loss would result in a decrease in the ability to conserve the
species.
We acknowledge that the Ninth Circuit Court of Appeals decision in
Defenders of Wildlife v. Norton, 258 F.3d 1136 (2001) can be
interpreted to require that in determining whether a species is
threatened or endangered throughout a significant portion of its range,
the Service should consider whether lost historical range (as opposed
to current range) constitutes a significant portion of the range of the
species at issue. While this is not our interpretation of the case or
the statute, we conclude that there are no such areas for the Siskiyou
Mountains salamander, the Applegate DPS of the Siskiyou salamander, the
Grider DPS of the Siskiyou salamander, or the Scott Bar salamander. As
we discussed in detail in our assessment of threats to each species,
there is no evidence of range contraction for any of the species. We
have no evidence to suggest that the occupied range of any member of
the Siskiyou Mountains salamander Complex is different from its
historical range.
In determining whether a species is threatened or endangered in a
significant portion of its range, we first identify any portions of the
range of the species that warrant further consideration. The range of a
species can theoretically be divided into portions in an infinite
number of ways. However, there is no purpose to analyzing portions of
the range that are not reasonably likely to be significant and
threatened or endangered. To identify only those portions that warrant
further consideration, we determine whether there is substantial
information indicating that (i) The portions may be significant and
(ii) the species may be in danger of extinction there or likely to
become so within the foreseeable future. In practice, a key part of
this analysis is whether the threats are geographically concentrated in
some way. If the threats to the species are essentially uniform
throughout its range, no portion is likely to warrant further
consideration. Moreover, if any concentration of threats applies only
to portions of the range that are unimportant to the conservation of
the species, such portions will not warrant further consideration.
If we identify any portions that warrant further consideration, we
then determine whether in fact the species is threatened or endangered
in any significant portion of its range.
[[Page 4416]]
Depending on the biology of the species, its range, and the threats it
faces, it may be more efficient for the Service to address the
significance question first, or the status question first. Thus, if the
Service determines that a portion of the range is not significant, the
Service need not determine whether the species is threatened or
endangered there. If the Service determines that the species is not
threatened or endangered in a portion of its range, the Service need
not determine if that portion is significant. If the Service determines
that both a portion of the range of a species is significant and the
species is threatened or endangered there, the Service will specify
that portion of the range as threatened or endangered pursuant to
section 4(c)(1) of the Act.
The terms ``resiliency,'' ``redundancy,'' and ``representation''
are intended to be indicators of the conservation value of portions of
the range. Resiliency of a species allows the species to recover from
periodic disturbance. A species will likely be more resilient if large
populations exist in high-quality habitat that is distributed
throughout the range of the species in such a way as to capture the
environmental variability found within the range of the species. In
addition, the portion may contribute to resiliency for other reasons--
for instance, it may contain an important concentration of certain
types of habitat that are necessary for the species to carry out its
life-history functions, such as breeding, feeding, migration,
dispersal, or wintering. Redundancy of populations may be needed to
provide a margin of safety for the species to withstand catastrophic
events. This does not mean that any portion that provides redundancy is
a significant portion of the range of a species. The idea is to
conserve enough areas of the range such that random perturbations in
the system act on only a few populations. Therefore, each area must be
examined based on whether that area provides an increment of redundancy
is important to the conservation of the species. Adequate
representation ensures that the species' adaptive capabilities are
conserved. Specifically, the portion should be evaluated to see how it
contributes to the genetic diversity of the species. The loss of
genetically based diversity may substantially reduce the ability of the
species to respond and adapt to future environmental changes. A
peripheral population may contribute meaningfully to representation if
there is evidence that it provides genetic diversity due to its
location on the margin of the species' habitat requirements.
Siskiyou Mountains Salamander
The Applegate and Grider DPSs together constitute the entirety of
the range of the Siskiyou Mountains salamander. We have previously
determined, however, that neither DPS is threatened or endangered
across its range. Therefore, according to the formal opinion on
significant portion of the range (USDOI 2007), we should then evaluate
whether any significant portion of the range of a DPS may warrant
listing.
Applegate Salamander DPS of Siskiyou Mountains Salamander
To determine whether the Applegate salamander DPS is threatened in
a significant portion of its range, we first addressed whether any
portions of the range of the Applegate salamander DPS warrant further
consideration. Our analysis indicates that the conservation status of
the species is essentially the same throughout its range; there is no
area within the range of the Applegate salamander DPS where potential
threats to this species are significantly concentrated or are
substantially greater than in other portions of the range. And, as we
explained in detail in our analysis of the status of the species, none
of the threats faced by the species, alone or in combination, are
sufficient to place it in danger of extinction now (endangered) or in
the foreseeable future (threatened).
We found no evidence that populations of Applegate salamander DPS
are concentrated in any geographic portion of the range that would
increase the vulnerability of this DPS to a particular threat. The 440
known Applegate salamander locations and suitable habitat are widely
distributed across the DPS's range, and large areas of suitable habitat
remain unsurveyed.
We have analyzed the threats to the Applegate salamander DPS and
have determined that they are not concentrated within any geographic
portion of the range, and no significant areas within the DPS's range
have been determined to face any greater threats. Potential threats to
the DPS on Federal lands are addressed by existing land use regulations
such as the NWFP, in combination with the Special Status Species
program, such that no areas face significant threats which are not
being managed. We find that private timberlands do not constitute a
significant proportion of the Applegate salamander DPS's range because
(1) Private lands constitute a minor proportion (15 percent) of the
range of the Applegate salamander, and (2) private lands within the
range of the species occur as small parcels in a ``checkerboard''
pattern with Federal lands or as isolated parcels, reducing the
potential for threats to be concentrated in a geographic portion of the
larger range. For these reasons, we find that there are no portions of
the Applegate salamander DPS's range that warrant further consideration
as significant portions of the range.
We do not find that the Applegate salamander DPS is in danger of
extinction (endangered) now, nor is it likely to become endangered
within the foreseeable future (threatened) throughout all or a
significant portion of its range. Therefore, listing the Applegate
salamander DPS as threatened or endangered under the Act is not
warranted at this time.
Grider Salamander DPS of Siskiyou Mountains Salamander
Applying the process described above for determining whether a
species is threatened in a significant portion of its range, we also
addressed whether any portions of the range of the Grider salamander
DPS warrant further consideration. Our evaluation of the distribution
of Grider salamander DPS populations and potential threats indicates
that the conservation status of the species is essentially the same
throughout its range; there is no area within the range of the Grider
salamander DPS where potential threats to this species are
significantly concentrated or are substantially greater than in other
portions of the range. And, as we explained in detail in our analysis
of the status of the species, none of the threats faced by the species,
alone or in combination, are sufficient to place it in danger of
extinction now (endangered) or in the foreseeable future (threatened).
We found no evidence that populations of this DPS are concentrated
in any geographic portion of the range that would increase the
vulnerability of this DPS to a particular threat. The 76 known Grider
salamander locations and suitable habitat are widely distributed across
the DPS's range, and large areas of suitable habitat remain unsurveyed.
We have analyzed the threats to the Grider salamander DPS and have
determined that they are not concentrated within any geographic portion
of the range, and no significant areas within the DPS's range have been
determined to face any greater threats. Potential threats to the DPS on
Federal lands are addressed by existing land use regulations such as
the NWFP, such that no areas face significant threats which are not
being managed. We find that
[[Page 4417]]
private timberlands do not constitute a significant proportion of the
Grider salamander DPS's range because (1) Private lands constitute a
minor proportion (9 percent) of the range of the Grider salamander DPS,
and (2) private lands within the range of the DPS occur as small
parcels in a ``checkerboard'' pattern with Federal lands or as isolated
parcels, reducing the potential for threats to be concentrated in a
geographic portion of the larger range. Based on the reasons described
above, we find that there are no portions of the Grider salamander
DPS's range that warrant further consideration as significant portions
of the range.
We do not find that the Grider salamander DPS is in danger of
extinction (endangered) now, nor is it likely to become endangered
within the foreseeable future (threatened) throughout all or a
significant portion of its range. Therefore, listing the Grider
salamander DPS as threatened or endangered under the Act is not
warranted at this time.
Scott Bar Salamander
To determine whether the Scott Bar salamander is threatened in a
significant portion of its range, we first addressed whether any
portions of the range of the Scott Bar salamander warrant further
consideration. Our evaluation of the distribution of Scott Bar
salamander populations and potential threats indicates that the
conservation status of the species is essentially the same throughout
its range; there is no area within the range of the Scott Bar
salamander where potential threats to this species are significantly
concentrated or are substantially greater than in other portions of the
range. And, as we explained in detail in our analysis of the status of
the species, none of the threats faced by the species, alone or in
combination, are sufficient to place it in danger of extinction now
(endangered) or in the foreseeable future (threatened).
We found no evidence that populations of Scott Bar salamanders are
concentrated in any geographic portion of the range that would increase
the vulnerability of this species to a particular threat. The 115 known
Scott Bar salamander locations and suitable habitat are widely
distributed across the species' range, and large areas of suitable
habitat remain unsurveyed. The higher numbers of salamander locations
on private lands is the result of mandatory surveys, and does not
suggest the presence of larger or more concentrated populations on
private lands.
Existing land use regulations, such as the NWFP, provide protection
for the Scott Bar salamander on Federal lands while CESA provides
substantial protection for the salamander on private lands in
California. Further, even if the CESA protections on private lands were
eliminated, the threats facing the Scott Bar salamander would not
significantly increase because the private lands are not concentrated
in a particular geographical area, but rather occur in a
``checkerboard'' pattern interspersed with Federal lands. This pattern
of landownership serves to reduce the potential impacts on the
salamander of timber harvest and other habitat disturbing activities on
the relatively small portion (22 percent) of the species range that
occurs on private lands, and to maintain redundancy, distribution, and
connectivity among Scott Bar salamander populations. For these reasons,
we conclude that there are no portions of the Scott Bar salamander's
range that warrant further consideration as significant portions of the
range.
We do not find that the Scott Bar salamander is in danger of
extinction (endangered) now, nor is it likely to become endangered
within the foreseeable future (threatened) throughout all or a
significant portion of its range. Therefore, listing the species as
threatened or endangered under the Act is not warranted at this time.
We make this finding at a time when Federal conservation efforts
focused specifically on Applegate, Grider, and Scott Bar salamanders
are in flux. Given the very recent discontinuation of the Survey and
Manage Program and the fact that Survey and Manage guidelines are still
applicable to ongoing Federal projects for at least another year,
Federal agencies have had little time to develop and implement
conservation strategies under their Special Status Species Programs.
The Conservation Strategy for the Siskiyou Mountains Salamander,
Northern Portion of the Range (Olson et al. 2007) covers the entire
range of the Applegate salamander; the KNF is currently finalizing a
Conservation Strategy for the Grider salamander and Scott Bar
salamander. Both of these conservation strategies are modeled closely
after the existing Survey and Manage guidance for the salamanders, but
neither was evaluated as an existing conservation effort under PECE, or
considered in our evaluation of threats to the species. Despite the
fact that we did not rely on these existing and potential conservation
efforts in our determination that the Siskiyou Mountains salamander
group does not warrant protection under the Act, we note that these
efforts by Federal agencies may in the future play an important role in
the conservation of the species by acting as a hedge against
uncertainty associated with future land management policies and our
understanding of the ecology of these species. This finding represents
our evaluation of the best currently available scientific information
on the poorly known species, the environment they inhabit, and land
management practices that may affect them, but we recognize the dynamic
nature of our knowledge and land management policy. Through our
participation in the development, implementation, and monitoring of
these Conservation Strategies, as well as in ongoing field research of
the species' habitat relationships, the Service will play a direct role
in the future management and status of these salamanders.
We will continue to assess the status of both clades of the
Siskiyou Mountains salamander and Scott Bar salamander by working with
the USFS, BLM, and other parties to the existing Conservation Strategy;
research scientists; and other individuals or groups interested in
contributing to the conservation of these species. Through our
participation in regular reviews of the Conservation Strategy for the
Siskiyou Mountains salamander, Northern Portion of the Range, we will
monitor its effectiveness in eliminating and reducing threats to the
Applegate salamander over the foreseeable future.
We are continuing our involvement in the evaluation of habitat
associations and effects of forest management on the Grider and Scott
Bar salamanders. In 2005, the Service's Yreka Fish and Wildlife Office
(YFWO), in cooperation with the USFS Redwood Sciences Laboratory and
Humboldt State University, initiated research into the comparative
abundance, population structure, and body condition of 60 Grider and
Scott Bar salamander populations across a gradient of habitat
conditions.
We request that you submit any new information concerning the
status of, or threats to, these species to our Yreka Fish and Wildlife
Office (see ADDRESSES section) whenever it becomes available. New
information will help us monitor these species and encourage their
conservation. If an emergency situation develops for these or any other
species, we will act to provide immediate protection.
References Cited
A complete list of all references cited herein is available, upon
request, from the Yreka Fish and Wildlife Office (see ADDRESSES
section).
[[Page 4418]]
Author
The primary authors of this notice are the staff of the Yreka Fish
and Wildlife Office (see ADDRESSES).
Authority
The authority for this action is section 4 of the Endangered
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).
Dated: January 14, 2008.
Kenneth Stansell,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. E8-918 Filed 1-23-08; 8:45 am]
BILLING CODE 4310-55-P