Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, Jiangxi Normal University, Ziyang Road 99, Nanchang, 330022, China.
Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, United Kingdom.
Ecology. 2017 Jun;98(6):1631-1639. doi: 10.1002/ecy.1830. Epub 2017 May 2.
Habitat destruction, characterized by patch loss and fragmentation, is a major driving force of species extinction, and understanding its mechanisms has become a central issue in biodiversity conservation. Numerous studies have explored the effect of patch loss on food web dynamics, but ignored the critical role of patch fragmentation. Here we develop an extended patch-dynamic model for a tri-trophic omnivory system with trophic-dependent dispersal in fragmented landscapes. We found that species display different vulnerabilities to both patch loss and fragmentation, depending on their dispersal range and trophic position. The resulting trophic structure varies depending on the degree of habitat loss and fragmentation, due to a tradeoff between bottom-up control on omnivores (dominated by patch loss) and dispersal limitation on intermediate consumers (dominated by patch fragmentation). Overall, we find that omnivory increases system robustness to habitat destruction relative to a simple food chain.
生境破坏以斑块损失和破碎化为特征，是物种灭绝的主要驱动力，理解其机制已成为生物多样性保护的核心问题。许多研究探讨了斑块损失对食物网动态的影响，但忽略了斑块破碎化的关键作用。在这里，我们在一个具有碎裂景观中依赖于营养级扩散的三营养级杂食性系统中，开发了一个扩展的斑块动态模型。我们发现，物种对斑块损失和破碎化的脆弱性不同，这取决于它们的扩散范围和营养级位置。由于杂食动物（受斑块损失主导）和中间消费者（受斑块破碎化主导）的扩散限制之间的权衡，由于生境损失和破碎化的程度不同，导致了不同的营养结构。总体而言，我们发现杂食性相对于简单食物链增加了系统对生境破坏的鲁棒性。
