Department of Environmental Sciences, Eidgenössische Technische Hochschule Zurich, CHN G 73.1, 8092 Zurich, Switzerland.
Proc Natl Acad Sci U S A. 2011 Mar 22;108(12):5127-32. doi: 10.1073/pnas.1018776108. Epub 2011 Mar 7.
Rising global demands for food and biofuels are driving forest clearance in the tropics. Oil-palm expansion contributes to biodiversity declines and carbon emissions in Southeast Asia. However, the magnitudes of these impacts remain largely unquantified until now. We produce a 250-m spatial resolution map of closed canopy oil-palm plantations in the lowlands of Peninsular Malaysia (2 million ha), Borneo (2.4 million ha), and Sumatra (3.9 million ha). We demonstrate that 6% (or ≈880,000 ha) of tropical peatlands in the region had been converted to oil-palm plantations by the early 2000s. Conversion of peatswamp forests to oil palm led to biodiversity declines of 1% in Borneo (equivalent to four species of forest-dwelling birds), 3.4% in Sumatra (16 species), and 12.1% in Peninsular Malaysia (46 species). This land-use change also contributed to the loss of ≈140 million Mg of aboveground biomass carbon, and annual emissions of ≈4.6 million Mg of belowground carbon from peat oxidation. Additionally, the loss of peatswamp forests implies the loss of carbon sequestration service through peat accumulation, which amounts to ≈660,000 Mg of carbon annually. By 2010, 2.3 million ha of peatswamp forests were clear-felled, and currently occur as degraded lands. Reforestation of these clearings could enhance biodiversity by up to ≈20%, whereas oil-palm establishment would exacerbate species losses by up to ≈12%. To safeguard the region's biodiversity and carbon stocks, conservation and reforestation efforts should target Central Kalimantan, Riau, and West Kalimantan, which retain three-quarters (3.9 million ha) of the remaining peatswamp forests in Southeast Asia.
全球对粮食和生物燃料的需求不断增加，导致热带地区的森林砍伐加剧。油棕的扩张导致了东南亚生物多样性的减少和碳排放。然而，直到现在，这些影响的规模在很大程度上仍未得到量化。我们制作了一幅 250 米空间分辨率的马来西亚半岛（200 万公顷）、婆罗洲（240 万公顷）和苏门答腊（390 万公顷）低地封闭树冠油棕种植园的地图。我们表明，到 21 世纪初，该地区 6%（约 88 万公顷）的热带泥炭地已被开垦为油棕种植园。将泥炭沼泽森林转换为油棕导致婆罗洲的生物多样性减少了 1%（相当于四种森林鸟类），苏门答腊减少了 3.4%（16 种），马来西亚半岛减少了 12.1%（46 种）。这种土地利用变化还导致约 1.4 亿吨地上生物量碳和每年约 460 万吨地下碳从泥炭氧化中损失。此外，泥炭沼泽森林的丧失意味着通过泥炭积累丧失了碳固存服务，每年约为 66 万吨碳。到 2010 年，已有 230 万公顷的泥炭沼泽森林被砍伐，目前已退化。这些采伐地的重新造林可以将生物多样性提高约 20%，而油棕的建立将使物种损失增加约 12%。为了保护该地区的生物多样性和碳储量，保护和重新造林工作应针对中加里曼丹、廖内和西加里曼丹，这三个地区保留了东南亚剩余的四分之三（390 万公顷）泥炭沼泽森林。
