1.0 DOCUMENT INFORMATION
1.1 Document Title: Relative LAI data
1.2 Revision Date: July 5, 2005
1.3 Document Summary: Relative leaf area index for 1993, 1994,
1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, and 2004.
1.4 Sponsor: Office of Biological and Environmental Research, U. S.
DOE
2.0 INVESTIGATOR
2.1 Investigator and data set contact:
P.J. Hanson (hansonpj@ornl.gov)2.2 Title Of Investigation:
Research Staff Member
Environmental Sciences Division
Oak Ridge National Laboratory
P.O. Box 2008, Building 1059
Oak Ridge, TN 37831-6422
3.0 DATA SUMMARY
Relative leaf area index for a given year based on the ratio of
understory
to overstory light.
4.0 PROCEDURES
Seasonal patterns of stand LAI were determined from an index of
relative
canopy coverage equal to one minus the ratio of the daily sum of
understory
photosynthetically active radiation (PAR at 1.5 m) to the daily sum of
overstory incident PAR. Values were converted to a 0 to 1
scale
by referencing raw ratios to the maximum values in late June and the
pre-leaf
out and post leaf senescence values of the ratio for adjusting the
respective
halves of the growing season to a zero basline. Changing
solar
angles kept us from using a single value of the zero baseline
throughout
the year. PAR measurements were made with quantum sensors
(LiCor
Inc., Lincoln, NB).
5.0 OBSERVATION NOTES
None
6.0 DATA ORGANIZATION
Data are provided in comma delimeted text files where the first line
includes the variable names and subsequent lines include the following
data by year.
6.1 Variable, Definition, and Units
Columns 2 through 9 = Y????
7.0 KNOWN ERRORS AND QUALITY ASSESSMENT
None
8.0 NOTES
8.1 Limitations of the data: None.
8.2 Known Problems With The Data: None.
8.3 Usage Guidance: None.
9.0 REFERENCES:
Hanson PJ, Todd DE, Joslin JD (2003) Canopy production. In: Hanson PJ, Wullschleger SD, Eds, North American Temperate Deciduous Forest Responses to Changing Precipitation Regimes. Ecological Studies, Vol. 166, Springer, New York, pp. 303-315.Hanson PJ, Todd DE, Huston MA, Joslin JD, Croker J,
and Augé RM (1998) Description and field performance of
the Walker Branch Throughfall Displacement Experiment: 1993-1996,
ORNL/TM-13586,
Oak Ridge National Laboratory, Oak Ridge, Tennessee.
10.0 DATA LISTING
Click on the following to view data for the listed year.
Once open the files can exported as text files with the 'Save As'
command.