Liao Jinbao, Bearup Daniel, Blasius Bernd
Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, Jiangxi Normal University, Ziyang Road 99, 330022 Nanchang, People's Republic of China
Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
Proc Biol Sci. 2017 Jul 26;284(1859). doi: 10.1098/rspb.2017.0350.
Habitat destruction, characterized by patch loss and fragmentation, is a key driver of biodiversity loss. There has been some progress in the theory of spatial food webs; however, to date, practically nothing is known about how patch configurational fragmentation influences multi-trophic food web dynamics. We develop a spatially extended patch-dynamic model for different food webs by linking patch connectivity with trophic-dependent dispersal (i.e. higher trophic levels displaying longer-range dispersal). Using this model, we find that species display different sensitivities to patch loss and fragmentation, depending on their trophic position and the overall food web structure. Relative to other food webs, omnivory structure significantly increases system robustness to habitat destruction, as feeding on different trophic levels increases the omnivore's persistence. Additionally, in food webs with a dispersal-competition trade-off between species, intermediate levels of habitat destruction can enhance biodiversity by creating refuges for the weaker competitor. This demonstrates that maximizing patch connectivity is not always effective for biodiversity maintenance, as in food webs containing indirect competition, doing so may lead to further species loss.
栖息地破坏，其特征为斑块丧失和破碎化，是生物多样性丧失的关键驱动因素。空间食物网理论已取得一些进展；然而，迄今为止，对于斑块构型破碎化如何影响多营养级食物网动态几乎一无所知。我们通过将斑块连通性与营养依赖型扩散（即较高营养级表现出更远距离的扩散）相联系，为不同食物网开发了一个空间扩展的斑块动态模型。利用这个模型，我们发现物种对斑块丧失和破碎化表现出不同的敏感性，这取决于它们的营养位置和整体食物网结构。相对于其他食物网，杂食结构显著提高了系统对栖息地破坏的稳健性，因为取食不同营养级增加了杂食动物的持久性。此外，在物种之间存在扩散 - 竞争权衡的食物网中，中等程度的栖息地破坏可以通过为较弱的竞争者创造避难所来增强生物多样性。这表明最大化斑块连通性对于生物多样性维持并非总是有效，因为在包含间接竞争的食物网中，这样做可能导致进一步的物种丧失。
