Data from: Effects of prey density, temperature and predator diversity on nonconsumptive predator-driven mortality in a freshwater food web

Nonconsumptive predator-driven mortality (NCM), defined as prey mortality due to predation that does not result in prey consumption, is an underestimated component of predator-prey interactions with possible implications for population dynamics and ecosystem functioning. However, the biotic and abiotic factors influencing this mortality component remain largely unexplored, leaving a gap in our understanding of the impacts of environmental change on ecological communities. We investigated the effects of temperature, prey density, and predator diversity and density on NCM in an aquatic food web module composed of dragonfly larvae (Aeshna cyanea) and marbled crayfish (Procambarus fallax f. virginalis) preying on common carp (Cyprinus carpio) fry. We found that NCM increased with prey density and depended on the functional diversity and density of the predator community. Warming significantly reduced NCM only in the dragonfly larvae but the magnitude depended on dragonfly larvae density. Our results indicate that energy transfer across trophic levels is more efficient due to lower NCM in functionally diverse predator communities, at lower resource densities and at higher temperatures. This suggests that environmental changes such as climate warming and reduced resource availability could increase the efficiency of energy transfer in food webs only if functionally diverse predator communities are conserved.

非捕食消耗性捕食致死效应（Nonconsumptive predator-driven mortality, NCM）被定义为因捕食行为未造成猎物消耗所引发的猎物死亡，这是一类被低估的捕食者-猎物相互作用组分，其可能对种群动态与生态系统功能产生重要影响。然而，调控该致死效应的生物与非生物因子仍未得到充分探索，使得我们在理解环境变化对生态群落的影响方面存在研究空白。我们以由蜻蜓幼虫（Aeshna cyanea）、大理石纹螯虾（Procambarus fallax f. virginalis）捕食普通鲤鱼（Cyprinus carpio）鱼苗构成的水生食物网模块为研究对象，探究了温度、猎物密度、捕食者功能多样性与捕食者密度对NCM的影响。研究发现，NCM随猎物密度升高而增加，且依赖于捕食者群落的功能多样性与密度。升温仅在蜻蜓幼虫组中显著降低了NCM，但其影响程度取决于蜻蜓幼虫的种群密度。我们的结果表明，在功能多样的捕食者群落、较低的资源密度以及较高的温度条件下，由于NCM水平更低，营养级间的能量传递效率更高。这意味着，若能保护功能多样的捕食者群落，气候变暖与资源可获得性降低等环境变化或可提升食物网的能量传递效率。