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DOCUMENTATION_FORMAT: PLANT
SAMPLE_ID: CRMS326v48
PLANT_TYPE: Mixed wetland species
PLANT: Chairmaker's bulrush, saltgrass, and saltmeadow cordgrass
LATIN_NAME: Schoenoplectus americanus (Pers.) Volk. ex Schinz & R. Keller, Distichlis spicata (L.) Greene, and Spartina patens (Ait.) Muhl.
COLLECTION_LOCALITY: Coastwide Reference Monitoring System (CRMS) site 326 subplot v48 to the marsh edge. CRMS326 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: 29.273499 deg. N
COLLECTION_LONGITUDE: 91.073669 deg. W
DATUM: NAD83
ORIGINAL_DONOR: Raymond F. Kokaly, USGS
SAMPLE_DESCRIPTION:
This spectrum is the average reflectance for a 50 m transect of marsh covered by mixed species. At the start of the transect, vegetation species composition and cover were measured in a 2x2 m plot. The values from the plot are given in the site vegetation description.
Collection Date
07-Jun-2010
Site Vegetation Description
The vegetation cover was 100%. The average height of herbaceous vegetation was 85 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 (%) _____________________________________ _____________ Schoenoplectus americanus 50 Distichlis spicata 45 Spartina patens 5 _____________________________________ _____________
The following table shows the cover by forb species in the plot:
Forb Species Cover (%) _____________________________________ _____________ none _____________________________________ _____________
Field Observations
At the start of the transect: no water on marsh, just damp sediment.
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 start and stop of the transect are 29.273601 N, 91.073899 W and 29.273394 N, 91.073432 W respectively (in decimal degrees, datum is NAD83).
Within the plot at the start of the transect, 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 14 spectral measurements recorded along the transect.
These spectra were collected using an ASD Field Spectrometer 3 (FS3) in reflectance mode, relative to a Spectralon reference panel.
While walking on the edges of the plot, 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 (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 following channels were deleted from the spectrum (set to a value of -1.23e+34) because of atmospheric contamination or high levels of noise:
410-420, 768-796, 1002-1100, 1447-1622, 1651-1669, and 2077-2151 corresponding to wavelengths
0.759-0.769, 1.117-1.145, 1.351-1.449, 1.796-1.971, 2.000-2.018, and 2.426-2.500
General Site Description
The transect 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 v48 at the start of the transect 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