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Clark and others 2007 USGS Data Series 231
Spectral Library splib06a Sample Description

TITLE: Rangeland L04-072 S30% G21% DESCRIPT


SAMPLE_ID: L04-072

PLANT_TYPE: Mixed rangeland shrubs, grasses, and forbs



COLLECTION_LOCALITY: Left Hand Creek, in the Grass Creek Management area of the Bureau of Land Management, is located in central Wyoming, approximately 20 miles northwest of Thermopolis, Wyoming

COLLECTION_LATITUDE: 43 deg. 56.025 min. N

COLLECTION_LONGITUDE: 108 deg. 48.252 min. W




This spectrum is the average reflectance for an area of rangeland covered by mixed shrubs, grasses and forbs as detailed in this description of site number L04-072.

Collection Date
The reflectance data were collected on 1-Jul-2004.

Site Vegetation Description
The total vegetation cover on this site was 57%. The following table shows the percent cover by cover class:

Cover Category, Sub-Category                Cover (%)
_____________________________      ____________________________
Vegetation, Total Cover                  57
Vegetation, Tree                            0
Vegetation, Shrub                          30
Vegetation, Grass                          21
Vegetation, Forb                            5
Non-vegetation, Total Cover              43
Non-vegetation, Litter                     not differentiated
Non-vegetation, Bare                       not differentiated
Non-vegetation, Other                      not differentiated
_____________________________      ____________________________

The following table shows the cover by shrub species in the site (for shrubs with greater than 2% cover):

Shrub Species                            Cover (%)    Avg. Height (cm)
_____________________________________  ____________  __________________
Artemisia tridentata                       29               33
_____________________________________  ____________  __________________

The following table shows the cover by grass species in the site (for grasses with greater than 2% cover):

Grass Species                             Cover (%)
_____________________________________  _____________
Pascopyrum smithii                          8
Nassella viridula                           4
_____________________________________  _____________

The following table shows the cover by forb species in the site (for forbs with greater than 2% cover):

Forb Species                             Cover (%)
_____________________________________  _____________
_____________________________________  _____________

Field Observations
No comments.

Site Orientation
The average elevation over the area of the site is 1923 meters (6309 feet). The average slope of the site is 20 percent, with a West aspect of 270 degrees.

Site Burn History
The area of this plot has not recently burned (since 1996).

Site Location, Dimensions, and Vegetation Sampling
The center coordinates of this rangeland plot are 43 deg. 56.025 min. N, 108 deg. 48.252 min. W (datum is NAD83). The diameter of this circular vegetation plot was 15.2 meters. Within this plot, four subplots of 0.5 meter diameter were established 5 meters from the center at the four cardinal directions (north, east, south and west). Within these subplots, grass and forb species were identified and associated percent cover of each were visually estimated. Litter cover and the percent area of bare ground were also visually estimated. For each shrub in the larger plot, the species was identified, the lateral dimensions were measured, and the height was measured. The cover of trees, shrubs, grasses, forbs, litter and bare ground were calculated from the full plot and subplot measurements. Field identifications of Tetradymia canescens (winterfat) were inconsistent between the 2003 and 2004 field seasons. In 2003, some shrubs were identified as Chrysothamnus nauseosus (gray rabbitbrush) and Krascheninnikovia lanata (winterfat). Later, it was determined that some of these shrubs were incorrectly identified and it was decided to label them all as Tetradymia canescens.

Spectral Measurement Procedures
This spectrum is the average of 85 measurements made throughout site L04-072. These spectra were collected using an ASD Full Range Field Pro spectrometer in reflectance mode, relative to a Spectralon reference panel. While walking through the site, the fiber optic cable was pointed at nadir (straight down) at approximately shoulder height. The instrument was programmed to record 6 second averages of reflectance while moving through the site (thus, each recorded spectrum was an average of 60 individual measurements). These recorded spectra were examined for artifacts due to low signal:noise, detector offsets and atmospheric contamination. Those spectra with large artifacts were not included in further processing. An average of the remaining 85 spectra was computed. This average spectrum was converted to absolute reflectance by multiplying by the reflectance spectrum of the Spectralon reference panel. The following channels were deleted (set to a value of -1.23e+34) from the spectrum because of remaining artifacts: 1-6, 410-413, 576-592, 761-801, 1006-1051, 1441-1591, 2111-2151 (corresponding to the wavelength ranges of 0.350-0.355, 0.759-0.762, 0.925-0.941, 1.110-1.150, 1.355-1.400, 1.790-1.940, and 2.460-2.510 microns).

Left Hand Creek General Description
The Left Hand Creek Study area is in central Wyoming, located 20 miles northwest of Thermopolis, Wyoming in the "Grass Creek Management Area," managed by the Worland Field Office of the Bureau of Land Management. The approximate center of the study area is 43.9608 degrees North latitude and 108.8828 degrees West longitude. The general area consists of lowland creeks (approximate average elevation of 1900 m) covered by mountain big sagebrush (Artemisia tridentata), grasses and forbs, interspersed with higher ridges (approximate average elevation of 2100 m) covered by mountain big sagebrush, grasses and forbs with some sparsely forested areas containing Limber pine (Pinus flexilis), and Rocky Mountain Juniper (Juniperus scopulorum) with Douglas-fir (Pseudotsuga menziesii var. glauca) on steeper north-facing slopes.

Project Background
This site was measured as part of a cooperative U.S. Geological Survey and Bureau of Land Management project funded by the Joint Fire Science Program.




Amount Weight
Percent, %
COMPOSITION: Water: %(of fresh weight)
COMPOSITION: Total_Chlorophyll: %(of fresh weight)
COMPOSITION: Chlorophyll_A: %(of fresh weight)
COMPOSITION: Chlorophyll_B: %(of fresh weight)
COMPOSITION: Nitrogen: %(of dry weight)
COMPOSITION: Lignin: %(of dry weight)
COMPOSITION: Cellulose: %(of dry weight)








SPECTRAL_PURITY: 1a2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment
LIB_SPECTRA: splib06a r 33651 g.s.=