Department of Environmental Systems Sciences, ETH Zürich, Zürich, Switzerland.
Department of Environmental Microbiology, Eawag, Dübendorf, Switzerland.
Ecol Lett. 2019 May;22(5):838-846. doi: 10.1111/ele.13241. Epub 2019 Feb 21.
Species interactions change when the external conditions change. How these changes affect microbial community properties is an open question. We address this question using a two-species consortium in which species interactions change from exploitation to competition depending on the carbon source provided. We built a mathematical model and calibrated it using single-species growth measurements. This model predicted that low frequencies of change between carbon sources lead to species loss, while intermediate and high frequencies of change maintained both species. We experimentally confirmed these predictions by growing co-cultures in fluctuating environments. These findings complement more established concepts of a diversity peak at intermediate disturbance frequencies. They also provide a mechanistic understanding for how the dynamics at the community level emerges from single-species behaviours and interspecific interactions. Our findings suggest that changes in species interactions can profoundly impact the ecological dynamics and properties of microbial systems.
当外部条件发生变化时，物种间的相互作用也会发生变化。这些变化如何影响微生物群落的特性是一个悬而未决的问题。我们使用一个双物种联合体来解决这个问题，在这个联合体中，物种间的相互作用会根据提供的碳源从利用变为竞争。我们构建了一个数学模型，并使用单一物种的生长测量数据对其进行了校准。该模型预测，碳源之间变化频率较低会导致物种丧失，而中间和较高的变化频率则能维持两个物种。我们通过在波动环境中培养共培养物来验证这些预测。这些发现补充了在中等干扰频率下多样性峰值的更成熟概念。它们还为群落水平的动态如何从单一物种行为和种间相互作用中产生提供了一种机制上的理解。我们的研究结果表明，物种间相互作用的变化可能会深刻影响微生物系统的生态动态和特性。
