Stability criteria for complex ecosystems
Stability criteria for complex ecosystems
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DOI：
10.1038/nature10832
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发表时间：
2012-03-08
期刊：
影响因子：
64.8
通讯作者：
Tang, Si
中科院分区：
文献类型：
--
作者：
Allesina, Stefano;Tang, Si
四十年前，梅证明(1,2)足够大或复杂的生态网络持续存在的概率接近于零，这与之前的预期相反(3-5)。梅分析了物种随机相互作用的大型网络(1,2,6)。然而，在自然系统中，物种对具有明确的相互作用（例如捕食者-猎物、互利或竞争）。在这里，我们将梅的结果扩展到这些关系中，发现捕食者与被捕食者之间的相互作用（稳定）与互利和竞争的相互作用（破坏稳定）之间存在显着差异。我们为所有情况提供分析稳定性标准。我们使用这些标准来证明，与直觉相反，当施加现实的食物网结构（7,8）或存在大量弱相互作用（9,10）时，捕食者-被捕食者网络的稳定性概率会降低。同样，二分互惠网络中的嵌套性（11-14）也会对稳定性产生负面影响。这些结果是通过分离网络结构和相互作用强度对稳定性的贡献而得出的。稳定的捕食者-被捕食者网络可以是任意大和复杂的，只要捕食者-被捕食者对紧密耦合。稳定性准则具有广泛的适用性，因为它们适用于任何微分方程组。
Forty years ago, May proved(1,2) that sufficiently large or complex ecological networks have a probability of persisting that is close to zero, contrary to previous expectations(3-5). May analysed large networks in which species interact at random(1,2,6). However, in natural systems pairs of species have well-defined interactions (for example predator-prey, mutualistic or competitive). Here we extend May's results to these relationships and find remarkable differences between predator-prey interactions, which are stabilizing, and mutualistic and competitive interactions, which are destabilizing. We provide analytic stability criteria for all cases. We use the criteria to prove that, counterintuitively, the probability of stability for predator-prey networks decreases when a realistic food web structure is imposed(7,8) or if there is a large preponderance of weak interactions(9,10). Similarly, stability is negatively affected by nestedness(11-14) in bipartite mutualistic networks. These results are found by separating the contribution of network structure and interaction strengths to stability. Stable predator-prey networks can be arbitrarily large and complex, provided that predator-prey pairs are tightly coupled. The stability criteria are widely applicable, because they hold for any system of differential equations.