Green G M, Sussman R W
Science. 1990 Apr 13;248(4952):212-5. doi: 10.1126/science.248.4952.212.
Madagascar is biologically one of the richest areas on Earth, and its plants and animals are among the most endangered. Satellite images and vegetation maps based on earlier aerial photographs were used to determine the extent of eastern rain forests in Madagascar and to monitor the rate of deforestation over a 35-year period. In 1985, 3.8 million hectares of rain forest remained, representing only 50 percent of the 7.6 million hectares existing in 1950 and 34 percent of the estimated orignal extent (11.2 million hectares). Between 1950 and 1985, the rate of deforestation averaged 111,000 hectares per year. Deforestation was most rapid in areas with low topographic relief and high population density. If cutting of forests continues at the same pace, only forests on the steepest slopes will survive the next 35 years.
马达加斯加在生物多样性方面是地球上最丰富的地区之一，但其动植物却处于最濒危的行列。基于早期航空照片的卫星图像和植被图被用于确定马达加斯加东部雨林的范围，并监测35年间的森林砍伐率。1985年，仅存380万公顷的雨林，这仅占1950年存在的760万公顷的50%，以及估计原始范围（1120万公顷）的34%。在1950年至1985年期间，森林砍伐率平均每年为11.1万公顷。在地形起伏小且人口密度高的地区，森林砍伐最为迅速。如果森林砍伐以同样的速度持续下去，那么在未来35年里，只有最陡峭山坡上的森林才能幸存。
