Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 29, 2003
Publication Date: January 29, 2004
Citation: Hunt, E.R. 2004. Comparison of stocking rates determined from remote sensing NDVI and geographic information data for Wyoming [abstracts]. 57th Annual Meeting of the Society for Range Management. p. 88.
Biweekly Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI) is commonly used to estimate vegetation primary production for large regions. For the state of Wyoming, average above-ground net primary production (1989-2000) was calculated from remotely sensed AVHRR NDVI, climatic data, and a land cover classification. Using the method of J. L. Holechek [1988 Rangelands 10(1):10-14] and other geographic information, stocking rates in animal-unit-months per hectare were calculated for 1-km2 grid cells. These stocking rates were compared to National Resource Conservation Service (NRCS) tables spatially extrapolated using a 1:500,000 scale soil geographic data layer produced by the University of Wyoming, Wyoming Geographic Information Science Center. In a cell-to-cell comparison, there was a significant, but weak, correlation between the two estimates of stocking rates. Various areas had large differences, for example, areas with subirrigated soils had substantially lower stocking rates determined from remote sensing. Overall, the spatial pattern of the two methods were similar, but the errors in transitional areas from one region to another indicate problems of scale for the various data layers.