Global scale assessment of the relative contribution of climate and non-climate factors on annual vegetation change

Abstract

The impact and its change on the Earth’s biosphere from climate and non-climate factors are of grave concern due to increasing human activities. In this study we used a systematic method to assess the relative importance of climate and non-climate factors on annual global and continental vegetation dynamics based on global NDVI at 1-km resolution and surface climate data from main stations of the World Meteorological Organization between April 1998 and December 2002. The indices of relative importance of climate and non-climate fluctuations on vegetation dynamics at each continent before and after July 2000 (two equal time periods) were also compared. Our results indicated that the vegetation dynamics on a continental and global scale during this short time period was dominated by climate  fluctuations, however, the relative importance of climate and non-climate factors on yearly vegetation dynamics differed among continents. Despite the dominant role of climate on vegetation dynamics during these two time periods for all continents, the relative importance of climate on vegetation dynamics increased slightly in south-east Asia, North America, Africa, Australia and New Zealand, but decreased slightly in South America, Central America, west Asia, north Asia, Europe and globally. This method may be helpful in monitoring the impacts from climate and non-climate factors on global vegetation dynamics.