Predator mass mortality events restructure food webs through trophic decoupling
Predator mass mortality events restructure food webs through trophic decoupling
复制标题
捕食者大规模死亡事件通过营养脱钩重组食物网
DOI：
10.1038/s41586-023-06931-7
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发表时间：
2024
期刊：
影响因子：
64.8
通讯作者：
Siepielski, Adam M.
中科院分区：
文献类型：
--
作者：
Tye, Simon P.;Fey, Samuel B.;Gibert, Jean P.;Siepielski, Adam M.
捕食者在构建生态系统中起着关键作用，，-。然而，全球范围内捕食者的减少正在加速，捕食者大规模死亡事件(MMEs) -快速大规模死亡-现在是人类世时代的象征。由于其罕见和不可预测的性质，我们对微型微型企业如何直接影响生态系统缺乏了解。过去的捕食者清除研究可能不足以理解微型微型生态系统的生态后果，因为在自然界中，死亡的捕食者在原地分解并产生资源脉冲，这可能通过暂时提高生产力来改变随后的生态系统动态。在这里，我们通过实验在三营养化淡水湖食物网中诱导MMEs，并报告了不同于捕食者损失或资源脉冲的生态动态，但可以从理论上预测。由于自上而下的捕食者控制减弱，微型微型企业导致了多样化的消费者和生产者社区的扩散，并通过捕食者分解产生了更强的自下而上的效应。与单独清除捕食者相比，MMEs后初级生产的增加抑制了消费群体的反应。因此，微生态系统产生的生物量动态与未受干扰系统最相似，表明它们可能是自然界的隐扰动。这些生物量动态导致了营养解耦，即捕食者对初级生产者的间接有益影响丧失，后来变为直接的自下而上效应，在强化的草食中刺激初级生产。这些结果揭示了中小微企业的生态特征，并证明了随着全球变化加剧而出现的新的生态动态预测的可行性。
Predators have a key role in structuring ecosystems, , –. However, predator loss is accelerating globally, –, and predator mass-mortality events (MMEs)—rapid large-scale die-offs—are now emblematic of the Anthropocene epoch. Owing to their rare and unpredictable nature, we lack an understanding of how MMEs immediately impact ecosystems. Past predator-removal studies,may be insufficient to understand the ecological consequences of MMEs because, in nature, dead predators decompose in situ and generate a resource pulse, which could alter ensuing ecosystem dynamics by temporarily enhancing productivity. Here we experimentally induce MMEs in tritrophic, freshwater lake food webs and report ecological dynamics that are distinct from predator losses,or resource pulses alone, but that can be predicted from theory. MMEs led to the proliferation of diverse consumer and producer communities resulting from weakened top-down predator control, –and stronger bottom-up effects through predator decomposition. In contrast to predator removals alone, enhanced primary production after MMEs dampened the consumer community response. As a consequence, MMEs generated biomass dynamics that were most similar to those of undisturbed systems, indicating that they may be cryptic disturbances in nature. These biomass dynamics led to trophic decoupling, whereby the indirect beneficial effects of predators on primary producers are lost and later materialize as direct bottom-up effects that stimulate primary production amid intensified herbivory. These results reveal ecological signatures of MMEs and demonstrate the feasibility of forecasting novel ecological dynamics arising with intensifying global change.