Ocean warming and species exploitation have already caused large‐scale reorganization of biological communities across the world. Accurate projections of future biodiversity change require a comprehensive understanding of how entire communities respond to global change. We combined a time‐dynamic integrated food web modeling approach (Ecosim) with previous data from community‐level mesocosm experiments to determine the independent and combined effects of ocean warming, ocean acidification and fisheries exploitation on a well‐managed temperate coastal ecosystem. The mesocosm parameters enabled important physiological and behavioral responses to climate stressors to be projected for trophic levels ranging from primary producers to top predators, including sharks. Through model simulations, we show that under sustainable rates of fisheries exploitation, near‐future warming or ocean acidification in isolation could benefit species biomass at higher trophic levels (e.g., mammals, birds, and demersal finfish) in their current climate ranges, with the exception of small pelagic fishes. However, under warming and acidification combined, biomass increases at higher trophic levels will be lower or absent, while in the longer term reduced productivity of prey species is unlikely to support the increased biomass at the top of the food web. We also show that increases in exploitation will suppress any positive effects of human‐driven climate change, causing individual species biomass to decrease at higher trophic levels. Nevertheless, total future potential biomass of some fisheries species in temperate areas might remain high, particularly under acidification, because unharvested opportunistic species will likely benefit from decreased competition and show an increase in biomass. Ecological indicators of species composition such as the Shannon diversity index decline under all climate change scenarios, suggesting a trade‐off between biomass gain and functional diversity. By coupling parameters from multilevel mesocosm food web experiments with dynamic food web models, we were able to simulate the generative mechanisms that drive complex responses of temperate marine ecosystems to global change. This approach, which blends theory with experimental data, provides new prospects for forecasting climate‐driven biodiversity change and its effects on ecosystem processes.

中文翻译：

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将中生态系统与模型相结合揭示了全球变暖和海洋酸化对温带海洋生态系统的影响


海洋变暖和物种开发已经导致世界各地生物群落的大规模重组。准确预测未来生物多样性变化需要全面了解整个社区如何应对全球变化。我们将时间动态综合食物网建模方法（Ecosim）与先前来自群落级中生态系统实验的数据相结合，以确定海洋变暖、海洋酸化和渔业开发对管理良好的温带沿海生态系统的独立和综合影响。中生态系统参数使得能够预测从初级生产者到包括鲨鱼在内的顶级捕食者的营养水平对气候压力源的重要生理和行为反应。通过模型模拟，我们表明，在可持续的渔业开发率下，近期的变暖或单独的海洋酸化可能有利于当前气候范围内较高营养级的物种生物量（例如哺乳动物、鸟类和底栖鱼类），小型中上层鱼类除外。然而，在变暖和酸化的共同作用下，较高营养级的生物量增加将较低或不增加，而从长远来看，猎物物种生产力的降低不太可能支持食物网顶部生物量的增加。我们还表明，开发利用的增加将抑制人类驱动的气候变化的任何积极影响，导致个别物种的生物量在较高营养级别减少。然而，温带地区一些渔业物种未来的潜在总生物量可能仍然很高，特别是在酸化条件下，因为未捕捞的机会性物种可能会受益于竞争的减少并显示出生物量的增加。 在所有气候变化情景下，物种组成的生态指标（例如香农多样性指数）都会下降，这表明生物量增益和功能多样性之间存在权衡。通过将多级中生态食物网实验的参数与动态食物网模型相结合，我们能够模拟驱动温带海洋生态系统对全球变化的复杂反应的生成机制。这种方法将理论与实验数据相结合，为预测气候驱动的生物多样性变化及其对生态系统过程的影响提供了新的前景。