Chalcraft David R, Resetarits William J
Department of Ecology, Ethology, and Evolution, University of Illinois, Urbana, Illinois 61801, USA.
Am Nat. 2003 Oct;162(4):390-402. doi: 10.1086/378210. Epub 2003 Sep 8.
Theoretical and empirical studies in community ecology often simplify their study system by lumping together species on the basis of trait similarities (e.g., their taxonomy, resource or microhabitat usage) and then assume species sharing similar traits are functionally similar. To date, no study has directly tested whether species more similar with respect to any of these traits are more similar in their functional effects on population or ecosystem processes. In this study, we examined the association between traits and functional effects of six different aquatic predatory vertebrates. We demonstrated that functional similarity across multiple response variables was not correlated with trait similarity, but differences in trait values were associated with significantly different effects on individual response variables. The exact relationship between species traits and functional effect of predators, however, was different for each response variable. Using traits to predict functional similarity among species may be useful when considering individual response variables, but only if it is known which traits have the greatest influence on the response variable of interest. It is doubtful that any one scheme will predict the functional similarity of species across a diverse array of response variables because each response will likely be strongly influenced by different traits.
群落生态学的理论和实证研究通常通过基于性状相似性（例如它们的分类学、资源或微生境利用）将物种归为一类来简化其研究系统，然后假设具有相似性状的物种在功能上是相似的。迄今为止，尚无研究直接检验在这些性状中的任何一个方面更相似的物种在对种群或生态系统过程的功能影响上是否也更相似。在本研究中，我们研究了六种不同水生捕食性脊椎动物的性状与功能影响之间的关联。我们证明，多个响应变量的功能相似性与性状相似性不相关，但性状值的差异与对单个响应变量的显著不同影响相关。然而，对于每个响应变量，物种性状与捕食者功能影响之间的确切关系是不同的。在考虑单个响应变量时，利用性状预测物种间的功能相似性可能是有用的，但前提是要知道哪些性状对感兴趣的响应变量影响最大。怀疑是否有任何一种方案能够预测跨各种响应变量的物种功能相似性，因为每个响应可能都受到不同性状的强烈影响。
