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《Biological conservation》2011,(1):548-557
Tropical species with narrow elevational ranges may be thermally specialized and vulnerable to global warming. Local studies of distributions along elevational gradients reveal small-scale patterns but do not allow generalizations among geographic regions or taxa. We critically assessed data from 249 studies of species elevational distributions in the American, African, and Asia-Pacific tropics. Of these, 150 had sufficient data quality, sampling intensity, elevational range, and freedom from serious habitat disturbance to permit robust across-study comparisons. We found four main patterns: (1) species classified as elevational specialists (upper- or lower-zone specialists) are relatively more frequent in the American than Asia-Pacific tropics, with African tropics being intermediate; (2) elevational specialists are rare on islands, especially oceanic and smaller continental islands, largely due to a paucity of upper-zone specialists; (3) a relatively high proportion of plants and ectothermic vertebrates (amphibians and reptiles) are upper-zone specialists; and (4) relatively few endothermic vertebrates (birds and mammals) are upper-zone specialists. Understanding these broad-scale trends will help identify taxa and geographic regions vulnerable to global warming and highlight future research priorities. 相似文献
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亚太地区主要国家林产品出口贸易利益及竞争力比较分析——基于增加值贸易核算法 总被引:1,自引:1,他引:0
文中从全球价值链视角出发,基于增加值贸易核算方法对亚太地区主要林产品贸易国的林产品贸易利益和竞争力进行测算,以此来测度并比较亚太地区各国在全球价值链下的真实获利情况,并为未来我国林产品对外贸易的发展决策提供借鉴。研究发现,加拿大、美国、印度尼西亚、俄罗斯4个国家在全球价值链中所处位置、竞争力和贸易利益高于中国和马来西亚,在全球价值链利益分配中居于有利地位。中国等发展中国家应该积极延长国内价值链,提升参与国际分工水平,增强对全球价值链参与度和控制力,由量的扩张转向质的提升。 相似文献
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