The Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 04523, USA.
Department of Mathematics and Statistics, Boston University, Boston, MA, USA.
Science. 2017 Oct 13;358(6360):230-234. doi: 10.1126/science.aam5962. Epub 2017 Sep 28.
The carbon balance of tropical ecosystems remains uncertain, with top-down atmospheric studies suggesting an overall sink and bottom-up ecological approaches indicating a modest net source. Here we use 12 years (2003 to 2014) of MODIS pantropical satellite data to quantify net annual changes in the aboveground carbon density of tropical woody live vegetation, providing direct, measurement-based evidence that the world's tropical forests are a net carbon source of 425.2 ± 92.0 teragrams of carbon per year (Tg C year). This net release of carbon consists of losses of 861.7 ± 80.2 Tg C year and gains of 436.5 ± 31.0 Tg C year Gains result from forest growth; losses result from deforestation and from reductions in carbon density within standing forests (degradation or disturbance), with the latter accounting for 68.9% of overall losses.
热带生态系统的碳平衡仍然不确定，大气自上而下的研究表明其为整体汇，而自下而上的生态方法则表明其为适度的净源。在这里，我们利用 MODIS 泛热带卫星数据 12 年（2003 年至 2014 年）的数据来量化热带木本活植被地上碳密度的年净变化，提供了直接的基于测量的证据，证明世界热带森林每年净释放 425.2 ± 92.0 太吨碳（Tg C year）。这一碳净释放量包括 861.7 ± 80.2 Tg C year 的损失和 436.5 ± 31.0 Tg C year 的增益。增益源自森林生长；损失源自森林砍伐以及现有森林中碳密度的降低（退化或干扰），后者占总损失的 68.9%。
