Food-web aggregation, methodological and functional issues
Food-web aggregation, methodological and functional issues
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食物网聚合、方法论和功能问题
DOI：
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发表时间：
2013
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通讯作者：
Gérard Lacroix
中科院分区：
文献类型：
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作者：
Benoît Gauzens;Stéphane Legendre;X. Lazzaro;Gérard Lacroix
食物网中的营养物种通常被聚集到更少的群体中，使用理论和经验方法，要么是为了模拟可管理性，要么是因为缺乏数据分辨率。文献中使用的食物网的分辨率的异质性导致了对它们用于建立一般拓扑规则的质疑。尽管越来越多的研究将拓扑学与生态系统功能联系起来，但我们仍然不知道物种的聚集如何影响我们对网络功能的感知。因此，我们重新检查了从将顶级捕食者觅食行为和生物量与食物网拓扑联系起来的实验操作中得出的结论(Lazzaro等人)。2009年)，根据不同的标准(分类、营养相似性、大小、专门知识)汇集了一个74个物种的网络。我们发现，尽管拓扑描述符值沿梯度变化很大，但在聚集梯度的很大一部分(2/3)上，最初的显着效应和功能性质仍然保持不变。聚合往往比第一类错误产生更多的II型错误(假阳性)，主张聚合网络中的大多数影响不是方法论上的人工制品。按分类、营养相似性和专业知识进行的聚集比按大小聚集(减少到40个节点)更好地保存了功能特性(分别减少到38、30和17个节点)。我们的结果表明，只要方法论方法标准化，集总水平不超过合理的阈值，就有可能将聚集网络的结构与生态系统属性联系起来。
Trophic species in food webs are often aggregated into fewer groups, using theoretical and empirical approaches, either for modelling tractability or because of the lack of data resolution. Heterogeneities in the resolution of food webs used in the literature have led to question their use to establish general topological rules. Despite an increasing number of studies relating topology to ecosystem functioning, we still have no idea on how species’ aggregation affects our perception of network functionalities. Therefore, we re-examined the conclusions drawn from an experimental manipulation relating top-predator foraging behaviour and biomass to food-web topology (Lazzaro et al. 2009) by aggregating a 74-species network according to different criteria (taxonomy, trophic similarity, size, expertise). We found that initial significant effects and functional properties were preserved over a large portion of the aggregation gradient (2/3) despite strong variations in the topological descriptor values along the gradient. Aggregation tended to produce more type II errors (false positive) than type I errors, advocating that most effects in aggregated networks are not methodological artefacts. Aggregation by taxonomy, trophic similarity and expertise better preserved functional properties (down to 38, 30 and 17 nodes, respectively) than aggregation by size (down to 40 nodes). Our results suggest that it is possible to relate the structure of aggregated networks to ecosystem properties provided that the methodological approaches are standardized and the level of lumping does not a exceed a reasonable threshold.