Abstract:

An estimation model of vegetation net primary production (NPP) based on remote sensing data and climatic data was presented on the support of GIS,with which,the NPP of terrestrial vegetation in the Upper Yangtze River Basin in 1981~2000 was estimated,the interannual variation patterns of the NPP and its responses to climatic factors were studied. The results showed that all the terrestrial vegetation types presented an increasing annual NPP in 1981~2000 except crop,with the greatest increment for coniferous forests.It was possible that the NPP had distinct variation due to artificial factors.The distributions of annual precipitation and temperature were quite similar to annual NPP,with increment from northwest to southeast.The interannual correlation between NPP and precipitation or temperature was weak as a whole.The area of regions where correlation coefficient was above 0.2 occupied for nearly 50% of total area.Their distributing presented complementary relationship.The area of regions where correlation coefficient was below -0.2 was small.The driving roles (intension or direction) of the climatic factors (precipitation and temperature) varied with location.