Submitted to: American Society for Photogrammetry and Remote Sensing Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: September 13, 2000
Publication Date: N/A
Net ecosystem carbon fluxes were measured, using ground and aircraft data, for a mixed-grass prairie site and a sagebrush steppe site in southeastern Wyoming. We determined that the sagebrush site was net-sink of carbon, whereas, the grassland site was in approximate carbon balance. We tested the hypothesis that previous land-use/land cover change may be responsible for current carbon fluxes by examining Landsat MSS and current Landsat 7 ETM+ images. For these ecosystems, vegetation strongly responds to climate, so Landsat NDVI data were corrected for differences in timing and amount of precipitation using a model developed with AVHRR NDVI data. Landsat NDVI based on years (1999 + 1992) - (1983 + 1973) showed that 81 percent of the pixels in the sagebrush study area increased over time, whereas, 73 percent of the pixels in the grassland study area showed no change over time. Thus, long-term change detection techniques showed the increase in vegetation cover was related to carbon balance for these two sites.