Study on the Relationship Between Different Ecosystems and Climate in China Using NOAA/AVHRR data

Multiyear (12a) NOAA/AVHRR NDVI and meteorological station data were used to study the relationship between different ecosystems and climate in China In order to investigate the responses of different vegetation types to inter annual climate variability, we classified 21 vegetation types using GIS and the principal component analysis (PCA) Monthly NDVI was got for each meteorological station through its longitude and latitude The relations between averaged NDVI and precipitation, and temperature suggest that precipitation plays a more important part for the ecosystem than temperature does in China The relationship between NDVI and climate at an averaged year shows that temperature has a stronger force than precipitation, while precipitation causes different responses of vegetation to climate The correlations of seasonal variations between NDVI and precipitation, and temperature indicate that the responses of ecosystem to inter annual variability of climate differ at seasonal level, and that NDVI data in winter are inappropriate for investigating the variability of ecosystems in northern China To study ecosystem climate relationship at annual level, the data within growing period (April to October) for vegetation in most parts of China were used, and the results show that ecosystem climate relations for different regions differ greatly In southern China, there is a negative correlation between precipitation and NDVI and a positive correlation between temperature and NDVI; and vice versa in northern China Additionally, we found there are two sensitive (statistical significant) regions in responses of fluctuation of climate, and one is ecotone of grass forest in northern China and the other is central part of Yunnan province in Southwest China, respectively