A Contemporary Assessment of Change in Humid Tropical Forests
A Contemporary Assessment of Change in Humid Tropical Forests
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DOI：
10.1111/j.1523-1739.2009.01333.x
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发表时间：
2009-12-01
影响因子：
6.3
通讯作者：
Emerson, Ruth
中科院分区：
文献类型：
--
作者：
Asner, Gregory P.;Rudel, Thomas K.;Emerson, Ruth
近几十年来，全世界潮湿热带森林的土地利用和土地覆盖变化的速度和地理范围都有所增加。对森林变化的泛热带地理进行评估是一项挑战，改进对热带地区人类足迹的估计对于了解生物多样性的潜在变化至关重要。我们结合了最近发表的和新的卫星观测结果，以及谷歌Earth的图像和文献综述，来估计当代全球森林砍伐、选择性砍伐和潮湿热带森林二次再生的程度。2000年至2005年间，大约1.4%的生物群落被砍伐。截至2005年，大约一半的潮湿热带森林生物群落的树木覆盖率为50%或更少。虽然不能直接与森林砍伐进行比较，但对选择性采伐的地理估计表明，2000年至2005年期间，至少20%的潮湿热带森林生物群落正在经历一定程度的木材采伐。森林恢复的估计甚至更不确定，但现有报告的汇编表明，2000年至少有1.2%的潮湿热带森林生物群落处于长期次生再生的某个阶段。近70%的再生报告表明，在丘陵、高地和山地环境中，森林再生被认为是大规模农业和牧场的边缘。我们对人类足迹的估计是保守的，因为它们没有考虑到非常小规模的森林砍伐、低强度的伐木和未报告的二次再生，也没有考虑到对热带森林生态系统的其他影响，如火灾和狩猎。我们的结果突出了整个潮湿热带地区森林变化的巨大地理范围，以及用于这种综合的科学和技术的相当大的局限性。
In recent decades the rate and geographic extent of land-use and land-cover change has increased throughout the world's humid tropical forests. The pan-tropical geography of forest change is a challenge to assess, and improved estimates of the human footprint in the tropics are critical to understanding potential changes in biodiversity. We combined recently published and new satellite observations, along with images from Google Earth and a literature review, to estimate the contemporary global extent of deforestation, selective logging, and secondary regrowth in humid tropical forests. Roughly 1.4% of the biome was deforested between 2000 and 2005. As of 2005, about half of the humid tropical forest biome contained 50% or less tree cover. Although not directly comparable to deforestation, geographic estimates of selective logging indicate that at least 20% of the humid tropical forest biome was undergoing some level of timber harvesting between 2000 and 2005. Forest recovery estimates are even less certain, but a compilation of available reports suggests that at least 1.2% of the humid tropical forest biome was in some stage of long-term secondary regrowth in 2000. Nearly 70% of the regrowth reports indicate forest regeneration in hilly, upland, and mountainous environments considered marginal for large-scale agriculture and ranching. Our estimates of the human footprint are conservative because they do not resolve very small-scale deforestation, low-intensity logging, and unreported secondary regrowth, nor do they incorporate other impacts on tropical forest ecosystems, such as fire and hunting. Our results highlight the enormous geographic extent of forest change throughout the humid tropics and the considerable limitations of the science and technology available for such a synthesis.