University of Tübingen, Tübingen, Germany.
University of Hohenheim, Stuttgart, Germany.
Commun Biol. 2023 Jul 4;6(1):690. doi: 10.1038/s42003-023-05060-1.
Competitive hierarchies in diverse ecological communities have long been thought to lead to instability and prevent coexistence. However, system stability has never been tested, and the relation between hierarchy and instability has never been explained in complex competition networks parameterised with data from direct observation. Here we test model stability of 30 multispecies bryozoan assemblages, using estimates of energy loss from observed interference competition to parameterise both the inter- and intraspecific interactions in the competition networks. We find that all competition networks are unstable. However, instability is mitigated considerably by asymmetries in the energy loss rates brought about by hierarchies of strong and weak competitors. This asymmetric organisation results in asymmetries in the interaction strengths, which reduces instability by keeping the weight of short (positive) and longer (positive and negative) feedback loops low. Our results support the idea that interference competition leads to instability and exclusion but demonstrate that this is not because of, but despite, competitive hierarchy.
长期以来，人们一直认为，不同生态群落中的竞争等级结构会导致不稳定性，并阻止共存。然而，系统稳定性从未得到过检验，而且在使用直接观察数据参数化的复杂竞争网络中，等级结构与不稳定性之间的关系也从未得到过解释。在这里，我们使用从观察到的干扰竞争中损失的能量来估计值，对 30 个多物种苔藓虫组合体的模型稳定性进行了测试，以参数化竞争网络中的种间和种内相互作用。我们发现，所有的竞争网络都是不稳定的。然而，通过强弱竞争者之间的能量损失率的等级结构带来的不对称性，大大缓解了不稳定性。这种不对称的组织导致了相互作用强度的不对称性，通过保持短（正）和长（正和负）反馈环的权重较低，从而降低了不稳定性。我们的结果支持了干扰竞争会导致不稳定性和排斥性的观点，但同时也表明，这种不稳定性不是因为竞争等级结构，而是尽管有竞争等级结构。
Zotero 插件
