Stepping in Elton's footprints: a general scaling model for body masses and trophic levels across ecosystems
Stepping in Elton's footprints: a general scaling model for body masses and trophic levels across ecosystems
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DOI：
10.1111/j.1461-0248.2010.01568.x
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发表时间：
2011-02-01
期刊：
影响因子：
8.8
通讯作者：
Jonsson, Tomas
中科院分区：
文献类型：
--
作者：
Riede, Jens O.;Brose, Ulrich;Jonsson, Tomas
尽管越来越多的人意识到身体大小和捕食者-猎物的体重比对生态网络稳定性的重要性，但我们对它们在生态系统中的分布的理解是不完整的。在这里，我们使用来自35个食物网(海洋、溪流、湖泊和陆地)的1313种捕食者(无脊椎动物、外温性和吸温性脊椎动物)的体重估计来研究捕食者和猎物大小、体质量比和捕食者营养水平之间的关系。在所有生态系统和捕食者类型中，除了溪流(在捕食者-猎物相互作用中似乎具有不同的大小结构)，我们发现(1)几何平均猎物质量随着捕食者质量的增加而增加，其幂指数大于1；(2)捕食者的大小随着营养水平的增加而增加。与我们的理论推导一致，我们表明这些关系的数量性质意味着捕食者-被捕食者的体质量比随着捕食者的营养水平而系统地降低。因此，平均而言，捕食者在食物网的顶部与猎物的大小更相似，而不是靠近底部的猎物。这些发现与传统的埃尔顿范式相矛盾，并对我们理解体重对食物网拓扑结构、群落动态和稳定性的限制有一定的意义。
P>Despite growing awareness of the significance of body-size and predator-prey body-mass ratios for the stability of ecological networks, our understanding of their distribution within ecosystems is incomplete. Here, we study the relationships between predator and prey size, body-mass ratios and predator trophic levels using body-mass estimates of 1313 predators (invertebrates, ectotherm and endotherm vertebrates) from 35 food-webs (marine, stream, lake and terrestrial). Across all ecosystem and predator types, except for streams (which appear to have a different size structure in their predator-prey interactions), we find that (1) geometric mean prey mass increases with predator mass with a power-law exponent greater than unity and (2) predator size increases with trophic level. Consistent with our theoretical derivations, we show that the quantitative nature of these relationships implies systematic decreases in predator-prey body-mass ratios with the trophic level of the predator. Thus, predators are, on an average, more similar in size to their prey at the top of food-webs than that closer to the base. These findings contradict the traditional Eltonian paradigm and have implications for our understanding of body-mass constraints on food-web topology, community dynamics and stability.