February Staff Notes

Saltcedar control and eradication efforts continued this fall/winter as it does every winter at Bitter Lake NWR.  Dormant-season cut-stump treatments with a 60% solution of triclopyr (Garlon 3A or Renovate) have been over 90% effective in killing treated saltcedar.  Dormant-season treatments are generally necessary at Bitter Lake to avoid risk to such non-target species as the federally threatened Pecos sunflower (an annual) that grows abundantly in saline wetlands.  Cooler temperatures and avoidance of rattlesnakes also makes fall/winter treatments more desirable.

This fall, a four-person SCA crew spent about 1.5 weeks cutting and treating saltcedar in wetland Unit 15.  Refuge staff, with the help of a BLM fire crew, spent a few days earlier getting the project started and a final follow-up was completed by refuge staff, working from an ATV, on a few plants missed by the SCA crew.  Renovate was used because of its aquatic label and the presence of federally endangered invertebrates in some of the springs in the wetland unit.  Later this winter, a prescribed fire will clean up the downed saltcedar and litter that stifles Pecos sunflower germination.  Litter will also be removed from a patch of Russian knapweed so that herbicides can be more effectively applied in the spring.  The wetland, highly visible from the refuge tour route, is pleasantly returning to its natural, open character.

In January, saltcedar removal occurred in Unit 7 along water delivery ditches and highly visible public-use areas, again using cut-stump and triclopyr treatments.  Saltcedar can shade-out Pecos sunflowers which are often noted growing within the former canopy areas of cut saltcedar.  The Unit 7 wetland is scheduled for burning the fall of 2006 to encourage the rare sunflower and enhance the appearance of the tour route after flowering in September of 2007 (and for years after).

Additional saltcedar removal work is beginning in the Unit 6 spring-ditch which is inhabited by rare invertebrates such as Koster’s springsnails and Noel’s amphipods.  The term work is emphasized because the trees are large, rooted in a steep bank, and often over-hang springs and deep mud.  After either the small trees are cut completely or the larger trees that over-hang the water are “frilled” with a hatchet and then left standing they are treated with triclopyr.  As saltcedar has probably never been removed from the area and a burn has not occurred in decades, there is now an abundance of dead fuel.  Dense stands of phragmites and cattail, which appear to degrade the invertebrate habitat, also occur in some areas.  Some of the dead fuel is being physically removed along with most of the recently cut saltcedar in hopes of conducting a follow-up, low intensity summer burn.  It is expected that the burn will leave some of the standing dead saltcedar while it also suppresses phragmites and cattail growth.  Phragmites normally increases with fire.  However, it is hoped that the opposite effect will result from the summer burn as the plants will be actively growing at that time.  If efforts are successful, work will continue on an additional stretch of the Unit 6 spring-ditch (saltcedar removal and summer burning).