Understanding what makes food webs stable has long been a goal of ecologists. Topological structure and the distribution and magnitude of interaction strengths in food webs have been shown to confer important stabilizing properties. However, our understanding of how variable species interactions affect food-web structure and stability is still in its infancy. Anthropogenic stress, such as acid mine drainage, is likely to place severe limitations on the food-web structures possible due to changes in community composition and body mass distributions. Here, we used mechanistic models to infer food-web structure and quantify stability in streams across a gradient of acid mine drainage. Multiple food webs were iterated for each community based on species pairwise interaction probabilities, in order to incorporate the variability of realistic food-web structure. We found that food-web structure was altered systematically with a 32-fold decrease in the number of links and a 2-fold increase in connectance across the gradient. Stability generally increased 6-fold with increasing acid mine drainage stress, regardless of how interaction strengths were estimated. However, the distribution of the stability measure, s, for some impacted communities separated into clusters of higher and lower magnitude depending on how interaction strengths were estimated. Management and restoration of impacted sites needs to consider their increased stability, as this may have important implications for the re-colonization of desirable species. Furthermore, active species introductions may be required to overcome the internal ecological inertia of affected communities.

中文翻译：

---

酸性矿山排水梯度中河流食物网结构的变化增加了当地社区的稳定性

了解什么使食物网稳定一直是生态学家的目标。食物网中的拓扑结构和相互作用强度的分布和大小已被证明赋予重要的稳定特性。然而，我们对可变物种相互作用如何影响食物网结构和稳定性的理解仍处于起步阶段。由于群落组成和体重分布的变化，人为压力，例如酸性矿井排水，可能会对食物网结构造成严重限制。在这里，我们使用机械模型来推断食物网结构并量化穿过酸性矿山排水梯度的溪流的稳定性。根据物种成对相互作用概率为每个群落迭代多个食物网，为了结合现实食物网结构的可变性。我们发现食物网结构被系统地改变，链接数量减少了 32 倍，梯度上的连接增加了 2 倍。无论相互作用强度如何估计，稳定性通常随着酸性矿山排水应力的增加而增加 6 倍。然而，根据相互作用强度的估计方式，一些受影响社区的稳定性度量 s 的分布分为较高和较低数量级的集群。受影响地点的管理和恢复需​​要考虑它们增加的稳定性，因为这可能对所需物种的重新定殖具有重要意义。此外，