Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318, Leipzig, Germany.
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103, Leipzig, Germany.
Ecol Lett. 2020 Jun;23(6):983-993. doi: 10.1111/ele.13500. Epub 2020 Apr 3.
Although numerous studies show that communities are jointly influenced by predation and competitive interactions, few have resolved how temporal variability in these interactions influences community assembly and stability. Here, we addressed this challenge in experimental microbial microcosms by employing empirical dynamic modelling tools to: (1) detect causal interactions between prey species in the absence and presence of a predator; (2) quantify the time-varying strength of these interactions and (3) explore stability in the resulting communities. Our findings show that predators boost the number of causal interactions among community members, and lead to reduced dynamic stability, but higher coexistence among prey species. These results correspond to time-varying changes in species interactions, including emergence of morphological characteristics that appeared to reduce predation, and indirectly facilitate growth of predator-susceptible species. Jointly, our findings suggest that careful consideration of both context and time may be necessary to predict and explain outcomes in multi-trophic systems.
尽管许多研究表明，群落受到捕食和竞争相互作用的共同影响，但很少有研究能够解决这些相互作用的时间可变性如何影响群落组装和稳定性。在这里，我们通过使用经验动态建模工具来解决实验微生物微宇宙中的这一挑战：(1)在没有和存在捕食者的情况下检测猎物物种之间的因果相互作用；(2)量化这些相互作用的时变强度；(3)探索由此产生的群落的稳定性。我们的研究结果表明，捕食者增加了群落成员之间因果相互作用的数量，并导致动态稳定性降低，但猎物物种之间的共存度增加。这些结果与物种相互作用的时变变化相对应，包括出现了似乎减少捕食的形态特征，间接地促进了对捕食者敏感物种的生长。总的来说，我们的研究结果表明，为了预测和解释多营养层系统的结果，可能需要仔细考虑背景和时间。
