The inter-annual variation characteristics of MLAI and ALAI were different among the global major ecological regions ( Figure 2 ); however, they shared four common features: ( 1 ) the ecological regions dominated by forest vegetation were basically on the rise from 1994 ( some from 1992 ), whereas the deserts were generally on the opposite and the circumstances of grassland types were in between; ( 2 ) since 2000 or the summer of 2002, the vegetation growth in the ecological regions dominated by the type of forest vegetation has shown a small declining trend in general; ( 3 ) in 1988, especially in the summer of 1989, the vegetation growth in most ecological regions  showed a low value followed by a small peak in 1990 and 1991; ( 4 ) the tropical deserts generally showed three sessions of 10-year fluctuation periods, including 1982~1992, 1993~2002 and 2003~2012.

From the inter-annual fluctuation curve of MLAI and ALAI for 19 major types of global terrestrial ecoregions in 31 years, it can be seen that the major driving force of their variations was climate change. The LAI's ascending trend from around 1994 especially after 2000 was associated with the global warming during the same period. From 1988 to 1989, the valley value of LAI was in accordance with the general cooling globally in that year. From 1990 to 1991, the small peak value of LAI was in accordance with the general warming globally in that year.
In the global terrestrial ecoregions, the ecological response of LAI's variations to global climate change is also sensitive and conforms to ecology rules, in that each ecoregion type in all ecological zones is basically in accordance with the corresponding climate type. Vegetation fluctuation features within ecological areas are related to global climate change. The response of change in vegetation to global warming since 1995, especially after 2000, is more obvious. The obvious low values of LAI during 1988~1989 corresponded to the common temperature-drop during that period.  This might be related to the so-called La Niña phenomenon; LAI peak value during 1990~1991 corresponded to the common temperature-rise, which might be related to the El Niño effect. The phenology of central United States in 2000~2012 obvious advanced, which was in conformity with the climate warming during the same period.