Overdispersion of body size in Australian desert lizard communities at local scales only: no evidence for the Narcissus effect
Overdispersion of body size in Australian desert lizard communities at local scales only: no evidence for the Narcissus effect
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DOI：
10.1007/s00442-007-0849-1
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发表时间：
2007-12-01
期刊：
影响因子：
2.7
通讯作者：
Foulkes, Jeff
中科院分区：
文献类型：
--
作者：
Rabosky, Daniel L.;Reid, Julian;Foulkes, Jeff
地方和区域进程都可能有助于地方规模的社区多样性和结构。尽管许多研究调查了当地或区域群落结构的模式，但很少有人探讨当地群落结构对区域物种库内模式的影响程度。在这里，我们研究了来自干旱澳大利亚的 Ctenotus 蜥蜴的体型大小在当地和区域规模的群落组装中的作用。长期以来，草蜥蜴因其在澳大利亚干旱地区的特殊物种多样性而闻名，之前的研究试图阐明这些蜥蜴群落内物种共存的过程。然而，关于种间竞争在草鱼群落的组装和维持中的作用尚未达成共识。我们研究了澳大利亚干旱内陆数百个地点的栉水牛群落，以检验当地和区域栉水牛群落内的体型相对于群落组装的无效模型应该过度分散的假设，并探讨了当地和区域尺度的体型分散之间的关系。结果表明，通过共生物种之间体型比例的差异来衡量，局部尺度上群落范围内的体型过度分散的现象是显着的。然而，我们没有发现区域物种池内体型过度分散的证据，这表明影响当地和区域尺度物种表型分布的过程之间缺乏对应性。我们认为，草鳅群落的大小比例恒定性可能是由于物种之间的当代生态相互作用或生态特征的位移造成的，并且我们讨论了对观察到的模式的替代解释。
Both local and regional processes may contribute to community diversity and structure at local scales. Although many studies have investigated patterns of local or regional community structure, few have addressed the extent to which local community structure influences patterns within regional species pools. Here we investigate the role of body size in community assembly at local and regional scales in Ctenotus lizards from arid Australia. Ctenotus has long been noted for its exceptional species diversity in the Australian arid-zone, and previous studies have attempted to elucidate the processes underlying species coexistence within communities of these lizards. However, no consensus has emerged on the role of interspecific competition in the assembly and maintenance of Ctenotus communities. We studied Ctenotus communities at several hundred sites in the arid interior of Australia to test the hypothesis that body sizes within local and regional Ctenotus assemblages should be overdispersed relative to null models of community assembly, and we explored the relationship between body size dispersion at local and regional scales. Results indicate a striking pattern of community-wide overdispersion of body size at local scales, as measured by the variance in size ratios among co-occurring species. However, we find no evidence for body size overdispersion within regional species pools, suggesting a lack of correspondence between processes influencing the distribution of species phenotypes at local and regional scales. We suggest that size ratio constancy in Ctenotus communities may have resulted from contemporary ecological interactions among species or ecological character displacement, and we discuss alternative explanations for the observed patterns.