Center for Population Biology, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.
Ecol Lett. 2010 Feb;13(2):194-201. doi: 10.1111/j.1461-0248.2009.01417.x. Epub 2009 Dec 29.
A rapidly accumulating body of research has shown that species diversity consistently affects the functioning of ecosystems. The incorporation of trophic complexity and the extension of this research to larger scales and natural ranges in species diversity remain as important challenges for understanding the true magnitude of these effects in natural systems. Here, we test whether the diversity of prey communities affects the magnitude of aggregate consumer effects. We conducted a meta-analysis of 57 consumer removal field experiments from a range of intertidal and subtidal hard substrate marine communities. We found that the richness of the prey community was the strongest predictor of the magnitude of consumer effects while controlling for habitat type, taxonomic composition, and other variables. Consumer removal increased aggregate prey abundance on average by 1200% at the lower limit of prey diversity (two species), but only 200% at the upper limit of 37 species. Importantly, compositional change was substantial at both high and low prey diversity, suggesting predation intensity did not vary with prey richness. Rather diverse prey communities appear to be more capable of maintaining abundance via compensatory responses, by containing prey species that are resistant to (or tolerant of) predators. These results suggest that the effects of species diversity on trophic interactions may scale consistently from small-scale manipulations to cross-community comparisons.
越来越多的研究表明，物种多样性会持续影响生态系统的功能。纳入营养复杂性，并将这项研究扩展到更大的规模和自然物种多样性范围，仍然是理解这些自然系统中实际影响的重要挑战。在这里，我们检验了猎物群落的多样性是否会影响消费者总体效应的大小。我们对来自一系列潮间带和亚潮带硬底海洋群落的 57 项消费者去除野外实验进行了荟萃分析。我们发现，猎物群落的丰富度是影响消费者效应大小的最强预测因子，而栖息地类型、分类组成和其他变量则被控制在一定范围内。消费者去除作用平均使猎物丰度在猎物多样性下限（两种物种）时增加了 1200%，但在上限（37 种）时仅增加了 200%。重要的是，在高多样性和低多样性时，组成变化都很大，这表明捕食强度并不随猎物丰富度而变化。相反，更多样化的猎物群落似乎更有能力通过补偿反应来维持丰度，因为它们包含了对捕食者有抵抗力（或容忍度）的猎物物种。这些结果表明，物种多样性对营养相互作用的影响可能从小规模操纵到跨群落比较，始终一致地进行扩展。
