Global test of Eltonian niche conservatism of nonnative freshwater fish species between their native and introduced ranges
Global test of Eltonian niche conservatism of nonnative freshwater fish species between their native and introduced ranges
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DOI：
10.1111/ecog.02007
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发表时间：
2017-03-01
期刊：
影响因子：
5.9
通讯作者：
Olden, Julian D.
中科院分区：
文献类型：
--
作者：
Comte, Lise;Cucherousset, Julien;Olden, Julian D.
尽管越来越多的证据表明生物相互作用限制了物种的分布及其在气候变化下的潜在重新分布，但最近对生态位保守主义的兴趣激增主要集中在格林内利（非生物）生态位，而很少有研究试图量化埃尔顿（生物或营养）生态位的潜在不稳定性。在这里，我们对来自全球 435 个种群的 32 种淡水鱼类的埃尔顿生态位的保守性进行了测试，这些淡水鱼类在引入范围和本地范围之间。我们使用稳定同位素数据来量化同位素生态位沿水平方向（δ C-13：指示消耗资源的来源）和垂直方向（δ N-15：描述营养位置）的生态位变化，以及整体同位素生态位宽度的变化。使用组合质心标准化同位素矢量分析并控制物种之间的系统发育相关性，我们证明引入的淡水鱼类在资源利用和营养位置方面表现出灵活性，超出了在其原生范围内观察到的自然变异水平。相比之下，生态位宽度仅在本地种群记录的限度内表现出变化，并且与平均同位素生态位位置的变化无关。在所有物种和引入历史中，我们发现对混合来源和中间营养位置的资源的更平衡获取的一致转变，表明鱼类成功融入接收群落的一般机制。促进或抑制物种改变其埃尔顿生态位的机制仍然未知，但营养灵活性可能有助于入侵物种的成功和生态影响以及未来全球变化下本地物种的范围变化。
Despite growing evidence that biotic interactions limit the distribution of species and their potential redistribution under climate change, the recent surge of interest in niche conservatism has predominantly focused on the Grinellian (abiotic) niche, whereas few studies have attempted to quantify potential lability in the Eltonian (biotic or trophic) niche. Here, we test for conservatism in the Eltonian niche of 32 freshwater fish species between their introduced and native ranges from 435 populations across the globe. We used stable isotope data to quantify niche shifts along the horizontal (delta C-13: indicating the origin of the resources consumed) and vertical (delta N-15: describing the trophic position) dimensions of the isotopic niche, as well as shifts in overall isotopic niche breadth. Using an assemblage centroid standardized isotope vector analysis and controlling for phylogenetic relatedness among species, we demonstrated that introduced freshwater fishes exhibited flexibility in both resource use and trophic position that was beyond levels of natural variability observed in their native ranges. By contrast, niche breadth showed variability only within the limits recorded in native populations and varied independently from shifts in mean isotopic niche positions. Across all species and introduction histories, we found a consistent shift towards more balanced acquisition of resources with mixed origins and at intermediate trophic positions, suggesting a general mechanism by which fish species successfully establish into recipient communities. The mechanisms that promote or inhibit species from shifting their Eltonian niche remains unknown, but trophic flexibility is likely to contribute to both the success and the ecological impacts of invasive species and range shifts of native species under future global change.