MMNDVI English utf8 dataset McMurdo Dry Valleys LTER Information Manager im@mcmlter.org pointOfContact 2020-09-09 ISO 19115-2 Geographic Information - North American Profile Metadata - Data with Biological Extensions ISO 19115-2:2009(E) Microbial mat biomass and Normalized Difference Vegetation Index (NDVI) values from Lake Fryxell Basin, Antarctica, January 2018 2020-09-09 publication Sarah Power Virginia Tech http://www.vt.edu/ snpower@vt.edu pointOfContact Mark Salvatore Northern Arizona University https://nau.edu mark.salvatore@nau.edu http://msalvatore.net pointOfContact Eric Sokol National Ecological Observatory Network (NEON) https://www.neonscience.org/ sokole@gmail.com http://sokole.blogspot.com/ pointOfContact Lee Stanish United States Geological Survey (USGS) https://www.usgs.gov/staff lstanish@gmail.com pointOfContact John "Jeb" Barrett Virginia Tech http://www.vt.edu/ jebarre@vt.edu https://www.biol.vt.edu/faculty/barrett/index.html pointOfContact documentDigital This package contains data collected from microbial mat surveys (i.e., percent cover, ash-free dry mass (AFDM), and pigment concentrations – chlorophyll-a, scytonemin, and carotenoids) associated with satellite-derived Normalized Difference Vegetation Index (NDVI) values from the Lake Fryxell Basin of Taylor Valley, located in the McMurdo Dry Valleys of Antarctica. The purpose of this study was to quantitatively compare key microbial mat characteristics to NDVI. Data were collected at seven plot locations within the Canada Glacier Antarctic Specially Protected Area (ASPA) near Canada Stream, as well as alongside Green Creek and McKnight Creek. NDVI values were derived from a WorldView-2 multispectral satellite image taken of the Lake Fryxell Basin on January 19, 2018, while biological ground surveying and sampling were conducted during the 2nd and 4th weeks of January 2018.  Name: Renée F. Brown Role: data manager completed McMurdo Dry Valleys LTER Information Manager im@mcmlter.org pointOfContact primary production theme LTER Core Areas English Coordinates taken from 1996-97 GPS measurements at center of creek where it enters Lake Fryxell Parent Stream: Canada Stream Provenance : GPS96-97.DOC ID: canada_mouth 163.074447600000 163.074447600000 -77.614922000000 -77.614922000000 Green Creek at mouth Description: Coordinates taken from 1996-97 GPS measurements at center of creek where it enters Lake Fryxell ID: green_mouth File Name :GPS96-97.DOC 163.063507080078 163.063507080078 -77.622589111328 -77.622589111328 McKnight Creek at mouth ID: mcknight_mouth 163.264724700000 163.264724700000 -77.599724000000 -77.599724000000 ground condition 2018-01-09 2018-01-25 https://mcm.lternet.edu/sites/default/files/data/MMNDVI_CHEMISTRY.csv MMNDVI_CHEMISTRY eng; US McMurdo Dry Valleys LTER MMNDVI_CHEMISTRY Data Source Definition : Microbial mat survey chemistry Number of Header Lines : 1 Orientation : Column Quote Character : "Field Delimiter : , false DATASET_CODE Internal dataset code. PLOT Plot location name where sample was collected. REPLICATE Replicate number within the associated plot. SCYTO Scytonemin concentration, expressed in micrograms per gram of dry soil. CARO Carotenoid concentration, expressed in micrograms per gram of dry soil. CHLA Chlorophyll-a concentration, expressed in micrograms per gram of dry soil. AFDM Ash-free dry mass content, expressed in milligrams per gram of dry soil. COMMENTS Comments regarding NA values. DBF https://mcm.lternet.edu/sites/default/files/data/MMNDVI_CHEMISTRY.csv https://mcm.lternet.edu/sites/default/files/data/MMNDVI_COVER.csv MMNDVI_COVER eng; US McMurdo Dry Valleys LTER MMNDVI_COVER Data Source Definition : Microbial mat survey percent cover Number of Header Lines : 1 Orientation : Column Quote Character : "Field Delimiter : , false DATASET_CODE Internal dataset code. PLOT Plot location name where sample was collected. COVER Percent cover value. DBF https://mcm.lternet.edu/sites/default/files/data/MMNDVI_COVER.csv https://mcm.lternet.edu/sites/default/files/data/MMNDVI_NDVI.csv MMNDVI_NDVI eng; US McMurdo Dry Valleys LTER MMNDVI_NDVI Data Source Definition : NDVI values Number of Header Lines : 1 Orientation : Column Quote Character : "Field Delimiter : , false DATASET_CODE Internal dataset code. PLOT Plot location name where sample was collected. NDVI Normalized Difference Vegetation Index (NDVI) values. DBF https://mcm.lternet.edu/sites/default/files/data/MMNDVI_NDVI.csv https://mcm.lternet.edu/sites/default/files/data/MMNDVI_LOCATIONS.csv MMNDVI_LOCATIONS eng; US McMurdo Dry Valleys LTER MMNDVI_LOCATIONS Data Source Definition : Plot locations Number of Header Lines : 1 Orientation : Column Quote Character : "Field Delimiter : , false DATASET_CODE Internal dataset code. PLOT Plot location name where sample was collected. LATITUDE Latitude of plot location. LONGITUDE Longitude of plot location. DBF https://mcm.lternet.edu/sites/default/files/data/MMNDVI_LOCATIONS.csv dataset Locations of visually conspicuous microbial mats outside of stream channels were selected for seven 100 m2 plots beside Canada Stream in the Canada Glacier Antarctic Specially Protected Area (ASPA), Green Creek, and McKnight Creek in the Lake Fryxell Basin. Plots Canada Stream-1, -2, -3, and -4 were all located in the lower flush of the ASPA and Canada Stream-5 was in the upper flush. Hemispherical photos of ground cover along with position data were taken every 5 m at each of the seven plots. Using a random stratified sampling design, we sampled microbial mat from 9 or 10 locations within each plot for pigment chemistry and ash-free dry mass (AFDM).The hemispherical photos were analyzed for microbial mat cover using ImageJ, an image analysis software. By converting the photos to binary black and white images, the software distinguished pixels representing microbial mats (black) from those representing bare soil or rocks (white). Estimates for percent cover were quantified using a histogram. Chlorophyll-a concentration was measured with a spectrophotometer (Shimadzu UV-1601) using a protocol that corrects for scytonemin concentration. The samples were dried at 105°C for 24 hrs and extracted in 10 mL of 90% unbuffered acetone using 0.5 g of mat, based on protocols from Garcia‐Pichel and Castenholz (1991) and standard methods employed by the McMurdo Dry Valleys Long Term Ecological Research program (MCM LTER). The samples were then left for 24 hrs in a dark room at ambient temperature for complete chlorophyll extraction. After centrifuging for 10 min at 4000 RPM, they were analyzed on a spectrophotometer using 10 mL cuvettes. The absorbances contributed by chlorophyll-a, carotenoids, and scytonemin were quantified at 663, 490, and 384 nm, respectively, using the trichromatic equations outlined in Garcia‐Pichel and Castenholz (1991). One sample from Canada Stream-2 had extremely high pigment concentrations overall, with values greater than 6 standard deviations of the mean chlorophyll-a concentrations for all observations, and it was removed from the dataset. AFDM was calculated by weighing approximately 0.25 g of oven-dried sample, combusting at 550°C for 60 min using a muffle furnace, and reweighing after cooling in a desiccator. Given the extremely low clay content of soils in this region, the rehydration of clays was assumed negligible, so the methods did not include rewetting samples to account for the hydration of clays.The WorldView-2 multispectral satellite (DigitalGlobe, Inc.) collected a cloud-free image of the Lake Fryxell Basin on January 19, 2018, within 10 days of our surveying and sampling. The image was georeferenced using ground control points and processed to atmospherically corrected surface reflectance using the Environment for Visualizing Images software (ENVI, Harris Geospatial). We calculated the normalized difference vegetation index (NDVI) for the image. Using ArcMap, we converted the NDVI image raster file to points and then selected the pixels whose centroids fell within the 100 m2 plot boundaries. Each plot corresponds to approximately 14-17 pixels (5.95 m2 per pixel) with unique NDVI values. Metadata Access Constraints: none Metadata Use Constraints: none annually McMurdo Dry Valleys LTER http://mcmlter.org/ pointOfContact