Does dispersal influence the strength of intraspecific competition in a stream salamander
Does dispersal influence the strength of intraspecific competition in a stream salamander
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扩散是否会影响溪蝾螈种内竞争的强度
DOI：
10.1111/jzo.12282
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发表时间：
2016
影响因子：
2
通讯作者：
W. Lowe
中科院分区：
文献类型：
--
作者：
J. Davenport;W. Lowe
元生态学强调扩散在连接空间中的局部过程中的作用。竞争就是这样一种局部过程，它会受到扩散的影响。扩散可以影响种内性状变异，从而影响种内竞争的强度，从而影响种内与种间相互作用的相对重要性。先前的研究表明，春季蝾螈，Gyrinophilus porphriticus，自我组织内流由一个共同的特点（身体状况）和扩散和基因流沿着流随坡度而变化。在此之前的工作的基础上，我们测试了扩散如何通过两种空间机制之一来影响种内竞争的强度：（1）通过影响竞争表现的性状对个体进行空间排序或（2）基因流的变化导致影响竞争表现的性状的进化分歧。为了测试这些替代机制，我们进行了一个中型实验，春季蝾螈从下游和上游网站的流与低和高速率的扩散和基因流。种内竞争性能的空间格局不同显着的低和高分散流。在低扩散流中，下游个体比上游个体具有更好的种内竞争能力，而在高扩散流中则相反。这些差异支持的空间排序机制，加强直接扩散的数据表明，高性能的个人更有可能移动上游的高分散流，并保持下游的低分散流。据我们所知，这是第一次，空间排序已被明确确定为有助于种内相互作用的强度。我们的研究强调了将自然扩散率整合到机械实验中以了解种内和种间相互作用强度的空间变异的重要性。
Metacommunity ecology emphasizes the role of dispersal in linking local processes across space. Competition is one such local process that can be affected by dispersal. Dispersal can influence intraspecific trait variation, thereby affecting the strength of intraspecific competition and, consequently, the relative importance of intra- versus interspecific interactions. Prior research has shown that spring salamanders, Gyrinophilus porphyriticus, self-organize within streams by a common trait (body condition) and that dispersal and gene flow along streams vary with slope. Building on this prior work, we tested how dispersal influences the strength of intraspecific competition via one of two spatial mechanisms: (1) spatial sorting of individuals by traits that affect competitive performance or (2) variation in gene flow resulting in evolutionary divergence of traits affecting competitive performance. To test these alternative mechanisms, we conducted a mesocosm experiment with spring salamanders from downstream and upstream sites of streams with low and high rates of dispersal and gene flow. Spatial patterns of intraspecific competitive performance differed significantly in the low- and high-dispersal streams. In the low-dispersal stream, downstream individuals were better intraspecific competitors than upstream individuals, whereas the opposite was true in the high-dispersal stream. These differences support the spatial sorting mechanism, reinforcing direct dispersal data showing that high-performance individuals are more likely to move upstream in the high-dispersal stream and to remain downstream in the low-dispersal stream. To our knowledge, this is the first time that spatial sorting has been explicitly identified as contributing to the strength of intraspecific interactions. Our study underscores the importance of integrating natural rates of dispersal into mechanistic experiments to understand spatial variability in the strength of intra- and interspecific species interactions.