Smith Thomas A H, Holt Robert D, Bruna Emilio M, Fletcher Robert J
Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, USA.
Department of Integrative Biology, University of Wisconsin-Madison, Madison, Florida, USA.
J Anim Ecol. 2025 Jun 24. doi: 10.1111/1365-2656.70089.
Global increases in habitat loss and fragmentation have resulted in non-habitat landcover, or the matrix, becoming an increasingly prominent feature of landscapes. The matrix can influence the population dynamics of species in fragments by modifying processes operating locally on individual patches (e.g. edge effects on survival) or at landscape scales (e.g. inter-patch dispersal). However, the relative magnitude of patch- vs. landscape-scale matrix effects on the populations found in patches remains unclear. We established 12 experimental landscapes in which we controlled for habitat amount and fragmentation while manipulating the quality of the matrix around (i) individual habitat patches and (ii) across the entire landscape in a factorial design. We then compared the magnitude of local- and landscape-scale matrix effects on a specialist herbivore, Chelinidea vittiger (Hemiptera: Coreidae). Population size in fragments was influenced by both patch- and landscape-scale treatments: Population size increased in patches surrounded by high-quality matrix, but only in landscapes dominated by low-quality matrix, due in part to decreased inter-patch movements in these landscapes. In contrast, the effects on both survival and reproductive output were solely at the patch-scale, with both lower in patches surrounded by low-quality matrix. Our results underscore the outsized importance of matrix habitat immediately adjacent to fragment edges-despite the fact that patch-scale manipulations affected only a fraction (3%) of the area that landscape-scale manipulations did, patch-scale effects were more common. The relationship between dispersal, population size and scale-dependent effects of matrix quality emphasizes the need to explicitly consider the spatial scale at which different processes operate when predicting responses to habitat fragmentation. Our results also suggest the matrix immediately adjacent to habitat remnants is of particular importance when considering alternative strategies for landscape conservation or restoration.
全球栖息地丧失和破碎化的加剧导致非栖息地土地覆盖（即基质）成为景观中日益突出的特征。基质可以通过改变在单个斑块上局部起作用的过程（例如对生存的边缘效应）或在景观尺度上起作用的过程（例如斑块间扩散）来影响片段中物种的种群动态。然而，斑块尺度与景观尺度的基质效应在斑块中种群上的相对大小仍不清楚。我们建立了12个实验景观，在其中控制栖息地数量和破碎化，同时通过析因设计操纵（i）单个栖息地斑块周围和（ii）整个景观的基质质量。然后，我们比较了局部和景观尺度的基质效应在一种专食性食草动物Chelinidea vittiger（半翅目：缘蝽科）上的大小。片段中的种群大小受到斑块尺度和景观尺度处理的影响：被高质量基质包围的斑块中种群大小增加，但仅在以低质量基质为主的景观中如此，部分原因是这些景观中斑块间的移动减少。相比之下，对生存和繁殖输出的影响仅在斑块尺度上，在被低质量基质包围的斑块中两者都较低。我们的结果强调了紧邻片段边缘的基质栖息地的重要性——尽管斑块尺度的操纵仅影响了景观尺度操纵所影响面积的一小部分（3%），但斑块尺度的效应更常见。扩散、种群大小与基质质量的尺度依赖性效应之间的关系强调了在预测对栖息地破碎化的反应时，需要明确考虑不同过程运作的空间尺度。我们的结果还表明，在考虑景观保护或恢复的替代策略时，紧邻栖息地残余的基质尤为重要。
