Functional links and robustness in food webs
Functional links and robustness in food webs
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DOI：
10.1098/rstb.2008.0214
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发表时间：
2009-06-27
影响因子：
6.3
通讯作者：
Pascual, Mercedes
中科院分区：
文献类型：
--
作者：
Allesina, Stefano;Bodini, Antonio;Pascual, Mercedes
生态系统对物种损失的稳健性是生态学的一个核心问题，因为目前的保护速度和许多物种受到人类影响的威胁，包括栖息地破坏和气候变化。从二级干扰的角度来看，鲁棒性已经在食物网的背景下，考虑物种相互作用的复杂网络，对扰动的反应。计算机去除实验研究了食物网的结构特性，这些特性增强或阻碍了生态系统对物种损失的鲁棒性，重点是枢纽，即联系最紧密的物种的作用。在这里，我们采取了不同的方法，并专注于连接本身的作用。我们表明，营养链可以分为功能和冗余的基础上，他们的贡献，鲁棒性。经验网络的分析表明，枢纽节点并不一定是最重要的物种，因为它们可能拥有许多冗余的链接。此外，功能连接的比例很高，并且在系统中是恒定的，无论大小和相互连接性如何。这种尺度模式的主要后果是，生态系统的鲁棒性可以大大降低物种的灭绝，即使这些并不导致任何二次灭绝。这就有可能导致生态系统崩溃的临界点。
The robustness of ecosystems to species losses is a central question in ecology, given the current pace of extinctions and the many species threatened by human impacts, including habitat destruction and climate change. Robustness from the perspective of secondary extinctions has been addressed in the context of food webs to consider the complex network of species interactions that underlie responses to perturbations. In-silico removal experiments have examined the structural properties of food webs that enhance or hamper the robustness of ecosystems to species losses, with a focus on the role of hubs, the most connected species. Here we take a different approach and focus on the role of the connections themselves. We show that trophic links can be divided into functional and redundant based on their contribution to robustness. The analysis of empirical webs shows that hubs are not necessarily the most important species as they may hold many redundant links. Furthermore, the fraction of functional connections is high and constant across systems regardless of size and interconnectedness. The main consequence of this scaling pattern is that ecosystem robustness can be considerably reduced by species extinctions even when these do not result in any secondary extinctions. This introduces the possibility of tipping points in the collapse of ecosystems.