Abstract Recent studies suggest that habitat amount is the main determinant of species richness, whereas habitat fragmentation has weak and mostly positive effects. Here, we challenge these ideas using a multi-taxa database including 2230 estimates of forest-dependent species richness from 1097 sampling sites across the Brazilian Atlantic Forest biodiversity hotspot. We used a structural equation modeling approach, accounting not only for direct effects of habitat loss, but also for its indirect effects (via habitat fragmentation), on the richness of forest-dependent species. We reveal that in addition to the effects of habitat loss, habitat fragmentation has negative impacts on animal species richness at intermediate (30–60%) levels of habitat amount, and on richness of plants at high (>60%) levels of habitat amount, both of which are mediated by edge effects. Based on these results, we argue that dismissing habitat fragmentation as a powerful force driving species extinction in tropical forest landscapes is premature and unsafe.

中文翻译：

---

栖息地破碎化造成的栖息地丧失的间接影响：对依赖森林的物种的跨类群分析

摘要 最近的研究表明，栖息地数量是物种丰富度的主要决定因素，而栖息地破碎化的影响很弱，而且大多是积极的。在这里，我们使用多分类群数据库挑战这些想法，该数据库包括来自巴西大西洋森林生物多样性热点的 1097 个采样点的 2230 个依赖森林的物种丰富度的估计值。我们使用了结构方程建模方法，不仅考虑了栖息地丧失的直接影响，还考虑了其​​对依赖森林的物种丰富度的间接影响（通过栖息地破碎化）。我们发现，除了栖息地丧失的影响外，栖息地破碎化对栖息地数量中等（30-60%）水平的动物物种丰富度和栖息地数量高（>60%）水平的植物丰富度有负面影响, 这两者都是由边缘效应介导的。基于这些结果，我们认为将栖息地破碎化视为推动热带森林景观物种灭绝的强大力量是不成熟和不安全的。