Characterizing ecosystem stability of northern China steppes using onset of green-up derived from time-series AVHRR NDVI data.
PRICE, K.P.* 1, F.YU 1, R.LEE 1, J.ELLIS 2 and P.SHI 3
University of Kansas, Lawrence, KS USA 1
Colorado State University, CO USA 2
Beijing Normal University, Beijing, China 3
This study has shown that Global Area Coverage (GAC) Advanced Very High Resolution Radiometer (AVHRR) maximum Normalized Difference Vegetation Index (NDVI) composites can be used to detect the onset of green-up for steppe ecosystems in Inner Mongolia. The study shows a strong linkage between onset of green-up and climatic factors. Since ecosystem stability of Inner Mongolian steppes is climatically controls, onset of green-up was used as an indicator of ecosystem stability. The coefficient of variation for the onset of green-up of the steppes/forest ecosystems was used as an Ecosystem Stability Index (ESI). The ESI showed meadow steppe/forest ecosystems to be most ecologically stable and the desert steppe to be the least stable. Large areas of typical steppe, near the desert steppe ecotone, exhibited similar ESI values to those of the desert steppe suggesting greater ecosystem instability in these typical steppe areas. This suggests that large expanses of typical steppe in this region are undergoing ecosystem degradation resulting in lower productivity and changes in land use practices.
Keywords: Climate changes, Vegetation Phenology, Grassland, Normalized Difference Vegetation Index (NDVI)
This abstract is being presented at: 4:15 PM in session:
Oral Session #64: Remote Sensing.