Stability of forest biodiversity

被引:147
作者
Clark, JS [1 ]
McLachlan, JS
机构
[1] Duke Univ, Ctr Global Change, Durham, NC 27708 USA
[2] Duke Univ, Nicholas Sch Environm, Durham, NC 27708 USA
基金
美国国家科学基金会; 美国国家航空航天局; 澳大利亚研究理事会;
关键词
D O I
10.1038/nature01632
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Two hypotheses to explain potentially high forest biodiversity have different implications for the number and kinds of species that can coexist and the potential loss of biodiversity in the absence of speciation. The first hypothesis involves stabilizing mechanisms, which include tradeoffs between species in terms of their capacities to disperse to sites where competition is weak(1-4), to exploit abundant resources effectively(5,6) and to compete for scarce resources(7). Stabilization results because competitors thrive at different times and places. An alternative, 'neutral model' suggests that stabilizing mechanisms may be superfluous. This explanation emphasizes 'equalizing' mechanisms(8), because competitive exclusion of similar species is slow. Lack of ecologically relevant differences means that abundances experience random 'neutral drift', with slow extinction(9-11). The relative importance of these two mechanisms is unknown, because assumptions and predictions involve broad temporal and spatial scales. Here we demonstrate that predictions of neutral drift are testable using palaeodata. The results demonstrate strong stabilizing forces. By contrast with the neutral prediction of increasing variance among sites over time, we show that variances in post-Glacial tree abundances among sites stabilize rapidly, and abundances remain coherent over broad geographical scales.
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页码:635 / 638
页数:4
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