Connectance determines invasion success via trophic interactions in model food webs
Connectance determines invasion success via trophic interactions in model food webs
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DOI：
10.1111/j.1600-0706.2010.18557.x
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发表时间：
2010-12-01
期刊：
影响因子：
3.4
通讯作者：
Lockwood, Julie L.
中科院分区：
文献类型：
--
作者：
Baiser, Benjamin;Russell, Gareth J.;Lockwood, Julie L.
人类引起的全球变化通过非本地物种的入侵和本地物种的灭绝极大地改变了食物网的结构和组成。物种缺失对食物网结构和稳定性的影响已引起广泛关注。然而，最近的经验证据表明，对于大多数类群，当地的物种丰富度增加了成功的入侵超过了这种规模的保护。这种模式表明，食物网，代表在当地规模的喂养相互作用，可能会增加物种丰富度。食物网结构如何与入侵物种的建立和成功入侵者对随后的食物网结构的影响的知识仍然是一个未知的，但潜在的重要方面的全球变化。在这里，我们探讨了食物网拓扑结构对入侵成功的影响，在模型食物网发展的假设，生物多样性的分布在各个营养级影响入侵的成功。我们的研究结果表明，一个连接（C）为基础的框架，预测入侵成功的食物网，由于C约束的方式，在每个营养级的物种数量，从而在给定的营养级的入侵者的潜在捕食者和猎物的数量。我们利用碳与14个已被充分研究的食物网中各营养级物种比例之间的关系，做出以下预测：1）随着碳含量的增加，食草动物在高碳网中的数量减少，基底入侵者的成功率会增加，（二）随着C的增加，草食动物的入侵成功率将下降，这是由于在C中，基础物种的比例下降，中间物种和杂食动物的比例增加。高C网3)随着C的增加，由于中间猎物物种的增加，顶级捕食者入侵成功率将增加。然而，目前尚不清楚营养结构的相对影响相比，经验已知的入侵成功的预测，如入侵性状，繁殖压力，资源的可用性。
Human induced global change has greatly altered the structure and composition of food webs through the invasion of non-native species and the extinction of native species. Much attention has been paid to the effects of species deletions on food web structure and stability. However, recent empirical evidence suggests that for most taxa local species richness has increased as successful invasions outpace extinctions at this scale. This pattern suggests that food webs, which represent feeding interactions at the local scale, may be increasing in species richness. Knowledge of how food web structure relates to invasive species establishment and the effect of successful invaders on subsequent food web structure remains an unknown but potentially important aspect of global change. Here we explore the effect of food web topology on invasion success in model food webs to develop hypotheses about how the distribution of biodiversity across trophic levels affects the success of invasion at each trophic level. Our results suggest a connectance (C) based framework for predicting invasion success in food webs due to the way that C constrains the number of species at each trophic level and thus the number of potential predators and prey for an invader at a given trophic level. We use the relationship between C and the proportion of species at each trophic level in 14 well studied food webs to make the following predictions; 1) the success of basal invaders will increase as C increases due to the decrease in herbivores in high C webs, 2) herbivore invasion success will decrease as C increases due to the decrease in the proportion of basal species and increase in intermediate species and omnivores in high C webs. 3) Top predator invasion success will increase as C increases due to the increase in intermediate prey species. However, it is not clear how the relative influence of trophic structure compares to empirically known predictors of invasion success such as invader traits, propagule pressure, and resource availability.