Vegetation response to active accumulated temperature patterns from 1960-2000 in China
中国区域1960~2000年活动积温年代变化和地表植被的适应性调整

The land surface\|atmosphere interaction accounts for regional distribution of multi\|rotational cropping and phenological patterns of vegetations. In response to the global warming, boundaries categorized with active accumulated temperature and degree days have been changing since 1980s. Correspondently, the area with two crops per annum and phenological patterns of vegetations in northern China has changed, and the boundaries for most categories of active accumulated temperature and degree days therein have expanded to the north. Meanwhile, the magnitudes of the categorized active accumulated temperature has increased significantly in 1990s relative to the period from 1960s-1980s, during which the contours of active accumulated temperature were overall constant without noticeable expand or shrinkage. Consistent with these changes, the area with two crops per annum, which is estimated from Discrete Fourier transform investigation by applying the LAI data set on a per pixel basis, has expanded northward. The increase in accumulative active temperature and degree days generally set the vegetations growth during 1990-1995 ahead by ten days compared with during 1980-1985 in the northern region of China, and those with two crops per annum by about 20 days.