Karatayev Vadim A, Munch Stephan B, Rogers Tanya L, Reuman Daniel C
Department of Biology, University of Maryland, College Park, MD 20742.
Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045.
Proc Natl Acad Sci U S A. 2025 Jan 7;122(1):e2404155121. doi: 10.1073/pnas.2404155121. Epub 2024 Dec 30.
Climate change is increasing the frequency of large-scale, extreme environmental events and flattening environmental gradients. Whether such changes will cause spatially synchronous, large-scale population declines depends on mechanisms that limit metapopulation synchrony, thereby promoting rescue effects and stability. Using long-term data and empirical dynamic models, we quantified spatial heterogeneity in density dependence, spatial heterogeneity in environmental responses, and environmental gradients to assess their role in inhibiting synchrony across 36 marine fish and invertebrate species. Overall, spatial heterogeneity in population dynamics was as important as environmental drivers in explaining population variation. This heterogeneity leads to weak synchrony in the California Current Ecosystem, where populations exhibit diverse responses to shared, large-scale environmental change. In contrast, in the Northeast U.S. Shelf Ecosystem, gradients in average environmental conditions among locations, filtered through nonlinear environmental response curves, limit synchrony. Simulations predict that environmental gradients and response diversity will continue to inhibit synchrony even if large-scale environmental extremes become common. However, if environmental gradients weaken, synchrony and periods of large-scale population decline may rise sharply among commercially important species on the Northeast Shelf. Our approach thus allows ecologists to 1) quantify how differences among local communities underpin landscape-scale resilience and 2) identify the kinds of future climatic changes most likely to amplify synchrony and erode species stability.
气候变化正在增加大规模极端环境事件的发生频率，并使环境梯度趋于平缓。这种变化是否会导致空间同步的大规模种群数量下降，取决于限制集合种群同步性的机制，从而促进救援效应和稳定性。利用长期数据和经验动态模型，我们量化了密度依赖性的空间异质性、环境响应的空间异质性以及环境梯度，以评估它们在抑制36种海洋鱼类和无脊椎动物物种同步性方面的作用。总体而言，种群动态的空间异质性在解释种群变化方面与环境驱动因素同样重要。这种异质性导致加利福尼亚洋流生态系统中的同步性较弱，在该生态系统中，种群对共同的大规模环境变化表现出多样的反应。相比之下，在美国东北大陆架生态系统中，各地点平均环境条件的梯度通过非线性环境响应曲线进行过滤，限制了同步性。模拟预测，即使大规模极端环境变得常见，环境梯度和响应多样性仍将继续抑制同步性。然而，如果环境梯度减弱，东北大陆架上具有商业重要性的物种之间的同步性和大规模种群数量下降的时期可能会急剧增加。因此，我们的方法使生态学家能够：1）量化当地群落之间的差异如何支撑景观尺度的恢复力；2）确定最有可能加剧同步性并削弱物种稳定性的未来气候变化类型。
