Department of Ecological Modelling, Helmholtz Centre for Environmental Research GmbH-UFZ Leipzig, Permoserstrasse 15, Leipzig 04318, Germany.
Department of Mathematics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
Nat Commun. 2017 Mar 17;8:14855. doi: 10.1038/ncomms14855.
Deforestation in the tropics is not only responsible for direct carbon emissions but also extends the forest edge wherein trees suffer increased mortality. Here we combine high-resolution (30 m) satellite maps of forest cover with estimates of the edge effect and show that 19% of the remaining area of tropical forests lies within 100 m of a forest edge. The tropics house around 50 million forest fragments and the length of the world's tropical forest edges sums to nearly 50 million km. Edge effects in tropical forests have caused an additional 10.3 Gt (2.1-14.4 Gt) of carbon emissions, which translates into 0.34 Gt per year and represents 31% of the currently estimated annual carbon releases due to tropical deforestation. Fragmentation substantially augments carbon emissions from tropical forests and must be taken into account when analysing the role of vegetation in the global carbon cycle.
热带森林的砍伐不仅会直接导致碳排放，还会延伸森林边缘，导致树木死亡率增加。在这里，我们结合了高分辨率（30 米）的森林覆盖卫星地图和对边缘效应的估计，结果表明，热带森林的剩余面积中有 19%位于森林边缘 100 米以内。热带地区大约有 5000 万片森林碎片，世界热带森林边缘的总长度接近 5000 万公里。热带森林的边缘效应导致了额外的 10.3 亿吨（2.1-14.4 亿吨）碳排放，相当于每年 0.34 亿吨，占目前因热带森林砍伐而估计的每年碳排放量的 31%。碎片化极大地增加了热带森林的碳排放，在分析植被在全球碳循环中的作用时必须考虑到这一点。
