Habitat fragmentation and effects of herbivore (howler monkey) abundances on bird species richness.
Habitat fragmentation and effects of herbivore (howler monkey) abundances on bird species richness.
复制标题
栖息地破碎化以及食草动物（吼猴）丰度对鸟类物种丰富度的影响。
DOI：
10.1890/05-0652
复制
发表时间：
2006
期刊：
影响因子：
4.8
通讯作者：
J. Terborgh
中科院分区：
文献类型：
--
作者：
K. Feeley;J. Terborgh
栖息地碎片化可以改变食草动物的丰富度，潜在地导致植物群落的变化，这些变化可以通过食物网传播，并最终影响其他重要的分类学群体，如鸟类。在这里，我们测试了在委内瑞拉拉戈古里(n=29个岛屿)最近孤立的一大组陆桥岛屿上红色咆哮猴子(Alouatta Senculus)的密度和鸟类物种丰富度之间的关系。这些岛屿中有几个拥有残存的咆哮猴种群，其密度比大陆上的高出30倍以上。这些“过度丰富的”食草动物此前已被证明对地上植物的生产力有很强的积极影响。我们预测，这应该会导致咆哮猴密度对鸟类物种丰富度产生积极的、间接的影响。在考虑了被动采样(物种丰富度与岛屿面积呈正相关的趋势，而不考虑栖息地质量差异)后，我们发现咆哮猴密度与鸟类物种丰富度呈显著正相关。路径分析结合了来自岛屿子集(n=9)的树木生长率数据，支持这样的假设，即咆哮猴对栖息地鸟类群落的影响是间接的，并通过植物生产力和栖息地质量的变化来调节。这些结果突出了不同的分类学群体通过间接相互作用和营养级联相互关联的可能性。
Habitat fragmentation can alter herbivore abundances, potentially causing changes in the plant community that can propagate through the food web and eventually influence other important taxonomic groups such as birds. Here we test the relationship between the density of red howler monkeys (Alouatta seniculus) and bird species richness on a large set of recently isolated land-bridge islands in Lago Guri, Venezuela (n = 29 islands). Several of these islands host relict populations of howler monkeys at densities up to more than 30 times greater than those on the mainland. These "hyperabundant" herbivores previously have been shown to have a strong positive influence on aboveground plant productivity. We predicted that this should lead to a positive, indirect effect of howler monkey density on bird species richness. After accounting for passive sampling (the tendency for species richness to be positively associated with island area, regardless of differences in habitat quality) we found a significant positive correlation between howler monkey density and bird species richness. A path analysis incorporating data on tree growth rates from a subset of islands (n = 9) supported the hypothesis that the effect of howler monkeys on the resident bird communities is indirect and is mediated through changes in plant productivity and habitat quality. These results highlight the potential for disparate taxonomic groups to be related through indirect interactions and trophic cascades.