MOE Key Laboratory of Biosystems Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China.
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.
Ecology. 2024 Jun;105(6):e4300. doi: 10.1002/ecy.4300. Epub 2024 Apr 22.
Ongoing habitat loss and fragmentation caused by human activities represent one of the greatest causes of biodiversity loss. However, the effects of habitat loss and fragmentation are not felt equally among species. Here, we examined how habitat loss influenced the diversity and abundance of species from different trophic levels, with different traits, by taking advantage of an inadvertent experiment that created habitat islands from a once continuous forest via the creation of the Thousand Island Lake, a large reservoir in China. On 28 of these islands with more than a 9000-fold difference in their area (0.12-1154 ha), we sampled plants, herbivorous insects, and predatory insects using effort-controlled sampling and analyses. This allowed us to discern whether any observed differences in species diversity were due to passive sampling alone or to demographic effects that disproportionately influenced some species relative to others. We found that while most metrics of sampling effort-controlled diversity increased with island area, the strength of the effect was exacerbated for species in higher trophic levels. When we more explicitly examined differences in species composition among islands, we found that the pairwise difference in species composition among islands was dominated by species turnover but that nestedness increased with differences in island area, indicating that some species are more likely to be absent from smaller islands. Furthermore, by examining trends of several dispersal-related traits of species, we found that species with lower dispersal propensity tended to be those that were lost from smaller islands, which was observed for herbivorous and predatory insects. Our results emphasize the importance of incorporating within-patch demographic effects, as well as the taxa and traits of species when understanding the influence of habitat loss on biodiversity.
人类活动导致的栖息地丧失和破碎化是生物多样性丧失的最大原因之一。然而，栖息地丧失和破碎化的影响在不同物种中并不均等。在这里，我们通过利用一个偶然的实验，研究了栖息地丧失如何影响不同营养级、具有不同特征的物种的多样性和丰度。该实验通过在中国的千岛湖（一个大型水库）的建造，将曾经连续的森林分割成岛屿。在这 28 个岛屿中的 28 个岛屿上，我们使用努力控制的采样和分析方法对植物、草食性昆虫和捕食性昆虫进行了采样。这使我们能够辨别观察到的物种多样性差异是由于被动采样还是由于人口统计学效应，这些效应不成比例地影响了某些物种相对于其他物种的数量。我们发现，虽然大多数与采样努力控制多样性相关的指标都随着岛屿面积的增加而增加，但这种效应的强度在营养级较高的物种中更为明显。当我们更明确地考察岛屿间物种组成的差异时，我们发现岛屿间物种组成的成对差异主要由物种更替驱动，但嵌套度随着岛屿面积的差异而增加，这表明某些物种更有可能从较小的岛屿上消失。此外，通过考察几个与扩散相关的物种特征的趋势，我们发现扩散倾向较低的物种更有可能从较小的岛屿上消失，这一现象在草食性和捕食性昆虫中都存在。我们的研究结果强调了在理解栖息地丧失对生物多样性的影响时，纳入斑块内人口统计学效应以及物种的分类群和特征的重要性。
