Asner Gregory P, Knapp David E, Broadbent Eben N, Oliveira Paulo J C, Keller Michael, Silva Jose N
Department of Global Ecology, Carnegie Institution of Washington, Stanford, CA 94305, USA.
Science. 2005 Oct 21;310(5747):480-2. doi: 10.1126/science.1118051.
Amazon deforestation has been measured by remote sensing for three decades. In comparison, selective logging has been mostly invisible to satellites. We developed a large-scale, high-resolution, automated remote-sensing analysis of selective logging in the top five timber-producing states of the Brazilian Amazon. Logged areas ranged from 12,075 to 19,823 square kilometers per year (+/-14%) between 1999 and 2002, equivalent to 60 to 123% of previously reported deforestation area. Up to 1200 square kilometers per year of logging were observed on conservation lands. Each year, 27 million to 50 million cubic meters of wood were extracted, and a gross flux of approximately 0.1 billion metric tons of carbon was destined for release to the atmosphere by logging.
通过遥感技术监测亚马逊地区森林砍伐情况已有三十年。相比之下，卫星大多难以察觉选择性采伐活动。我们针对巴西亚马逊地区木材产量最高的五个州开展了大规模、高分辨率的选择性采伐自动化遥感分析。1999年至2002年间，每年的采伐面积在12,075至19,823平方公里之间（±14%），相当于此前报告的森林砍伐面积的60%至123%。在保护区内每年观察到的采伐面积达1200平方公里。每年采伐的木材量为2700万至5000万立方米，采伐活动导致约10亿吨碳的总通量注定会释放到大气中。
