The distance dependence prediction of the Janzen-Connell hypothesis: a meta-analysis
The distance dependence prediction of the Janzen-Connell hypothesis: a meta-analysis
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DOI：
10.1034/j.1600-0706.2003.12235.x
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发表时间：
2003-12-01
期刊：
影响因子：
3.4
通讯作者：
Gurevitch, J
中科院分区：
文献类型：
--
作者：
Hyatt, LA;Rosenberg, MS;Gurevitch, J
Janzen-Connell假说解释了热带多样性的维持是通过以父母为中心的传播模式和距离和密度依赖的繁殖体生存的相互作用来实现的。这些效应被认为有助于热带森林内物种的均匀分布，从而增强了多样性。该假说的预测之一是，种子和幼苗的存活率应该随着亲本距离的增加而提高。虽然有许多针对个别物种的独立测试，但很少有综合研究将这些数据放在一起来测试其跨物种的有效性。本文报道了一个荟萃分析的结果，距离对提高繁殖体生存的影响，采用比值比效应大小度量。我们发现没有普遍支持的距离依赖的预测的假设，并得出结论，进一步的测试，以探讨这一假设作为一个多样性维持机制是不必要的。然而，我们确实发现，与热带地区相比，温带地区与亲本的距离会略微降低存活率，并且我们看到了比种子更有力的证据来支持幼苗的假设。繁殖体存活率随与亲本距离的增加而提高的现象可能对特定物种的种群生物学很重要，但它不是跨群落、生活史阶段或生活形式的普遍现象。
The Janzen-Connell hypothesis explains the maintenance of tropical diversity through the interacting effects of parent-centered dispersal patterns and distance- and density-dependent propagule survival. These effects were thought to support regular spacing of species within tropical forest, enhancing diversity. One of the predictions of the hypothesis is that seed and seedling survival should improve with increased parental distance. Although there are many independent tests of this hypothesis for individual species, there are few synthetic studies that have brought these data together to test its validity across species. This paper reports the results of a meta-analysis of the effect of distance on enhancing propagule survival, employing an odds-ratio effect size metric. We found no general support for the distance-dependent prediction of the hypothesis, and conclude that further testing to explore this hypothesis as a diversity-maintaining mechanism is unnecessary. However, we did find that distance from parent slightly reduces survivorship in the temperate zone, as contrasted with the tropics, and we saw stronger evidence in support of the hypothesis for seedlings than for seeds. The phenomenon of enhanced propagule survival with distance from the parent may be important for the population biology of particular species, but it is not a general phenomenon across communities, life history stages or life forms.