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DOCUMENTATION_FORMAT: PLANT
SAMPLE_ID: CRMS326v84
PLANT_TYPE: Mixed wetland species
PLANT: Saltgrass, saltmeadow cordgrass, and sturdy bulrush,
LATIN_NAME: Distichlis spicata (L.) Greene, Spartina patens (Ait.) Muhl., and Schoenoplectus robustus (Pursh) M.T. Strong
COLLECTION_LOCALITY: Coastwide Reference Monitoring System (CRMS) site 326 subplot v84. CRMS326v84 is located in southern Louisiana, approximately 127 kilometers southwest of New Orleans, Louisiana, in the western part of the Terrebonne hydrologic basin on the coast of the Gulf of Mexico.
COLLECTION_LATITUDE: 29.272902 deg. N
COLLECTION_LONGITUDE: 91.073126 deg. W
DATUM: NAD83
ORIGINAL_DONOR: Raymond F. Kokaly, USGS
SAMPLE_DESCRIPTION:
This spectrum is the average reflectance (using an artificial light source) for a 2x2 m area of marsh covered by mixed species as detailed in the site vegetation description.
Collection Date
07-Jun-2010
Site Vegetation Description
The total vegetation cover on this site was 100%. The average height of herbaceous vegetation was 82 cm. The following table shows the percent cover by cover class:
Cover Category, Sub-Category Cover (%) _____________________________ ____________________________ Vegetation, Total Cover 100 Vegetation, Tree 0 Vegetation, Shrub 0 Vegetation, Grass 100 Vegetation, Forb 0 Non-vegetation, Total Cover 0 Non-vegetation, Litter 0 Non-vegetation, Bare 0 Non-vegetation, Water 0 Non-vegetation, Other 0 _____________________________ ____________________________
The following table shows the cover by shrub species in the plot:
Shrub Species Cover (%) _____________________________________ ____________ none _____________________________________ ____________
The following table shows the cover by grass species in the plot:
Grass Species Cover (%) __________________________________________________ _____________ Distichlis spicata (L.) Greene 65 Spartina patens (Ait.) Muhl. 20 Schoenoplectus robustus (Pursh) M.T. Strong 20 __________________________________________________ _____________
The following table shows the cover by forb species in the plot:
Forb Species Cover (%) _____________________________________ _____________ none _____________________________________ _____________
Field Observations
Water Level is 0.06 ft above marsh.
Site Classification
The area has been predominantly classified as brackish marsh (see http://lacoast.gov/crms2/home.aspx).
Plot Location, Dimensions, and Vegetation Sampling
The coordinates of the southeast corner of the 2x2 m plot are 29.272902 N, 91.073126 W (in decimal degrees, datum is NAD83).
Within the plot, vegetation species were identified and the percent cover of each species was visually estimated.
Spectral Measurement and Processing Methods
This spectrum is the average of 24 spectral measurements recorded throughout the plot.
These spectra were collected using an ASD Field Spectrometer 3 (FS3) in reflectance mode, relative to a Spectralon reference panel.
While walking around the edges of the plot, the contact probe attachement (an artificial light source with a restricted, 1 cm diameter, field of view)
was used to measure the reflectance spectra of bundles of leaves and stems. Plant stems and leaves in the top 30 cm of the canopy were bunched together.
The contact probe was pressed against the optically thick bundle and a spectrum was recorded at two positions along the length of each bundle.
The instrument was programmed to record 6 second averages of reflectance (thus, each recorded spectrum was an average of 60 individual measurements).
The average spectrum was converted to absolute reflectance by multiplying by the reflectance spectrum of the Spectralon reference panel.
The first 50 channels(0.35 - 0.40 microns) and the last 30 channels (2.47 - 2.50 microns) in the spectral measurement show relatively high levels of noise.
General Site Description
The plot is located in southern Louisiana, approximately 127 kilometers southwest of New Orleans, Louisiana.
It is in the western part of the Terrebonne hydrologic basin on the coast of the Gulf of Mexico.
For additional information on the CRMS site see http://lacoast.gov/crms2/home.aspx
Project Background
This site was measured as part of joint work between the USGS Denver Spectroscopy Laboratory and the
Coastal Restoration Assessment Branch of the USGS National Wetlands Research Center, Baton Rouge.
This spectrum was used in the following publication:
Kokaly, R.F., Couvillion, B.R., Holloway, J.M., Roberts, D.A., Ustin, S.L., Peterson, S.H., Khanna, S., and Piazza, S.C., 2013,
Spectroscopic remote sensing of the distribution and persistence of oil from the Deepwater Horizon spill in Barataria Bay marshes,
Remote Sensing of Environment, Volume 129, Pages 210-230. http://dx.doi.org/10.1016/j.rse.2012.10.028
IMAGE_OF_SAMPLE: in the site layout diagram, the subplot location is indicated by the matching number within the parentheses
END_SAMPLE_DESCRIPTION.
COMPOSITIONAL_ANALYSIS_TYPE: None
COMPOSITION_DISCUSSION:
END_COMPOSITION_DISCUSSION.
TRACE_ELEMENT_ANALYSIS:
TRACE_ELEMENT_DISCUSSION:
END_TRACE_ELEMENT_DISCUSSION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1a2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns