Lee Tien Ming, Jetz Walter
Ecology, Behavior and Evolution Section, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093-0116, USA.
Proc Biol Sci. 2008 Jun 7;275(1640):1261-70. doi: 10.1098/rspb.2007.1732.
Global biodiversity is under significant threat from the combined effects of human-induced climate and land-use change. Covering 12% of the Earth's terrestrial surface, protected areas are crucial for conserving biodiversity and supporting ecological processes beneficial to human well-being, but their selection and design are usually uninformed about future global change. Here, we quantify the exposure of the global reserve network to projected climate and land-use change according to the Millennium Ecosystem Assessment and set these threats in relation to the conservation value and capacity of biogeographic and geopolitical regions. We find that geographical patterns of past human impact on the land cover only poorly predict those of forecasted change, thus revealing the inadequacy of existing global conservation prioritization templates. Projected conservation risk, measured as regional levels of land-cover change in relation to area protected, is the greatest at high latitudes (due to climate change) and tropics/subtropics (due to land-use change). Only some high-latitude nations prone to high conservation risk are also of high conservation value, but their high relative wealth may facilitate additional conservation efforts. In contrast, most low-latitude nations tend to be of high conservation value, but they often have limited capacity for conservation which may exacerbate the global biodiversity extinction crisis. While our approach will clearly benefit from improved land-cover projections and a thorough understanding of how species range will shift under climate change, our results provide a first global quantitative demonstration of the urgent need to consider future environmental change in reserve-based conservation planning. They further highlight the pressing need for new reserves in target regions and support a much extended 'north-south' transfer of conservation resources that maximizes biodiversity conservation while mitigating global climate change.
全球生物多样性正受到人为引起的气候和土地利用变化综合影响的重大威胁。保护区覆盖了地球陆地表面的12%，对于保护生物多样性和支持有益于人类福祉的生态过程至关重要，但其选择和设计通常未考虑未来的全球变化。在此，我们根据千年生态系统评估，量化全球保护区网络面临的预计气候和土地利用变化的风险，并将这些威胁与生物地理和地缘政治区域的保护价值及能力联系起来。我们发现，过去人类对土地覆盖的影响的地理模式只能很勉强地预测未来变化的模式，从而揭示了现有全球保护优先排序模板的不足之处。预计的保护风险，以与保护区面积相关的土地覆盖变化区域水平来衡量，在高纬度地区（由于气候变化）和热带/亚热带地区（由于土地利用变化）最大。只有一些面临高保护风险的高纬度国家也具有高保护价值，但其较高的相对财富可能有助于加大保护力度。相比之下，大多数低纬度国家往往具有高保护价值，但它们的保护能力往往有限，这可能会加剧全球生物多样性灭绝危机。虽然我们的方法显然将受益于改进的土地覆盖预测以及对物种分布在气候变化下如何变化的透彻理解，但我们的结果首次在全球范围内定量证明了在基于保护区的保护规划中考虑未来环境变化的迫切需要。它们进一步凸显了在目标区域设立新保护区的迫切需求，并支持大幅扩大“南北”保护资源转移，以在缓解全球气候变化的同时最大限度地保护生物多样性。
