Outcomes of management efforts to recover or restore populations of harvested species can be highly dependent on environmental and community context. Predator–prey interactions can alter recovery trajectories, and the timing of management actions within multi-trophic level harvest scenarios may influence the dynamics of recovery and lead to management trade-offs. Recent work using a generalist predator–prey model suggests that management promoting synchronized recovery of predators and prey leads to faster and less variable recovery trajectories than sequential recovery (predator or prey first). However, more complex communities may require different management actions to minimize recovery time and variability. Here, we use a tri-trophic level rocky reef community dynamics model with size-structure and fisheries at multiple trophic levels to investigate the importance of three ecological processes to recovery of fished communities: (1) size-structured predation, (2) non-consumptive effects of predators on prey behavior, and (3) varying levels of recruitment. We also test the effects of initiating recovery from community states associated with varying degrees of fishery-induced degradation and develop a simulation in which the basal resource (kelp) is harvested. In this system, a predator-first closure generally leads to the least volatile and quickest recovery, whether from a kelp forest, urchin barren, or intermediate community state. The benefits gained by selecting this strategy are magnified when recovering from the degraded community, the urchin barren, because initial conditions in the degraded state lead to lengthy recovery times. However, the shape of the size-structured predation relationship can strongly affect recovery volatility, where the differences between alternate management strategies are negated with size-independent predation. External recruitment reduces return times by bolstering the predatory lobster population. These results show that in a tightly linked tri-trophic level food web with top-down control, a predator-first fishery closure can be the most effective strategy to reduce volatility and shorten recovery, particularly when the system is starting from the degraded community state. Given the ubiquity of top predator loss across many ecosystems, we highlight the value of incorporating insights from community ecology into ecosystem management.

中文翻译：

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跨多个营养级捕捞海带森林恢复过程中的瞬态动态


恢复或恢复收获物种种群的管理工作的结果可能高度依赖于环境和社区背景。捕食者与猎物的相互作用可以改变恢复轨迹，多营养级收获场景中管理行动的时机可能会影响恢复的动态并导致管理权衡。最近使用通用捕食者-被捕食者模型的研究表明，促进捕食者和猎物同步恢复的管理比顺序恢复（首先是捕食者或猎物）导致更快且变化更少的恢复轨迹。然而，更复杂的社区可能需要不同的管理行动，以尽量减少恢复时间和变异性。在这里，我们使用具有尺寸结构和多个营养级渔业的三营养级岩礁群落动态模型来研究三个生态过程对捕捞群落恢复的重要性：（1）尺寸结构捕食，（2）非捕食- 捕食者对猎物行为的消耗影响，以及（3）不同水平的招募。我们还测试了与不同程度的渔业引起的退化相关的社区状态的启动恢复的效果，并开发了收获基础资源（海带）的模拟。在这个系统中，捕食者优先的关闭通常会导致波动性最小且恢复最快，无论是来自海带森林、海胆贫瘠之地还是中间群落状态。当从退化的群落（海胆荒地）中恢复时，选择这种策略所获得的好处会被放大，因为退化状态的初始条件会导致漫长的恢复时间。 然而，大小结构的捕食关系的形状可以强烈影响恢复波动性，其中替代管理策略之间的差异被大小无关的捕食所抵消。外部招募通过增加捕食性龙虾数量来减少返回时间。这些结果表明，在自上而下控制的紧密相连的三营养级食物网中，捕食者优先的渔业关闭可能是减少波动性和缩短恢复时间的最有效策略，特别是当系统从退化的群落状态开始时。鉴于许多生态系统中普遍存在顶级捕食者丧失的情况，我们强调将群落生态学的见解纳入生态系统管理的价值。