Seasonal Changes in Vegetation Activity in Response to Climate Changes in China between 1982 and 1999
1982-1999年我国陆地植被活动对气候变化响应的季节差异

In the present study, using normalized difference vegetati on index (NDVI) as an indicator of vegetation activity, seasonal trends of vegetation activity and their dynamic responses to climate changes in China were explored based on remotely sensed data (NOAA-AVHRR) from 1 982 to 1999. As a result, spatially averaged seasonal NDVI in China showed a pronounced increase in all four seasons (spring, summer, autumn and win ter) during the past 18 years. The average spring NDVI indicated the most significant increase (P<0.001) with a mean rate of 1.3%, while the average autumn NDVI showed the least increase (P=0.075). Analyzing int erannual changes in seasonal mean NDVI by vegetation type, it was fou nd that the advance of growing season was a major way for response of vegetation activity to climate changes and that the way exhibited a large regional heterogeneity. In the past 18 years, regions with the largest increase rate of summer NDVI appeared in Northwest China and the Tibetan Plateau, while areas with that of spring NDVI occurred i n the eastern part of the country.