This paper analyzed changes in the Amazon rainforest from 1982 to 2012 by combining GLASS LAI data with a global ecological classification map published by FAO in 2000. This approach harnesses the advantages of previous studies in terms of precision and time resolution. Moreover,the combination of single-point and analytical methods in the present work can fully reflect the changing status of rainforest vegetation. Previous studies regarded the entire area of South America as a study area; by contrast,the present research applies dynamic and static boundaries and considers the changes in the dynamic range of the rainforest. At the same time,the changes in the targeted research area are emphasized. Results show that the leaf area index of the Amazon rainforest fluctuated over a period of 31 years; after 2000,this index first decreased first and then increased smoothly. In terms of spatial distribution,the leaf area index of the tropical rainforest in Brazil and of other parts of the rainforest margins declined significantly over the same period. Meanwhile,the boundary in the southeast shrank constantly because of the deforestation attributed to human development activities,and the leaf area index of the rainforest interior increased considerably because of global warming. The results of the present work were consistent with those of previous studies; therefore,the current study shows that GLASS LAI,which is subject to the independent intellectual rights of China,can be used to monitor the long-term status of surface vegetation in large areas.

Amazon rainforest;LAI;remote sensing;ecological environment;change monitoring