Theoretical Aquatic Ecology and Ecophysiology group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.
Aquatic Food Web Interactions group (I.R.T.A), Microorganisms Genome and Environment Lab (L.M.G.E.), UMR CNRS 6023, Université Clermont Auvergne, Aubière, France.
Ecol Lett. 2019 Jul;22(7):1104-1114. doi: 10.1111/ele.13267. Epub 2019 Apr 23.
Theory predicts that resource variability hinders consumer performance. How this effect depends on the temporal structure of resource fluctuations encountered by individuals remains poorly understood. Combining modelling and growth experiments with Daphnia magna, we decompose the complexity of resource fluctuations and test the effect of resource variance, supply peak timing (i.e. phase) and co-limiting resource covariance along a gradient from high to low frequencies reflecting fine- to coarse-grained environments. Our results show that resource storage can buffer growth at high frequencies, but yields a sensitivity of growth to resource peak timing at lower ones. When two resources covary, negative covariance causes stronger growth depression at low frequencies. However, negative covariance might be beneficial at intermediate frequencies, an effect that can be explained by digestive acclimation. Our study provides a mechanistic basis for understanding how alterations of the environmental grain size affect consumers experiencing variable nutritional quality in nature.
理论预测，资源可变性会阻碍消费者的表现。但个体所遇到的资源波动的时间结构如何影响这种效果，目前仍知之甚少。我们通过结合使用模型和生长实验，利用大型水蚤，对资源波动的复杂性进行了分解，并沿着一个从高到低的频率梯度，测试了资源方差、供应峰值时间（即相位）和限制资源协变的影响，该频率梯度反映了从细颗粒到粗颗粒的环境。我们的研究结果表明，资源储存可以在高频下缓冲生长，但在低频下会导致对资源峰值时间的敏感性增加。当两种资源协变时，负协变会在低频下导致更强的生长抑制。然而，负协变在中频可能是有益的，这种效应可以通过消化驯化来解释。我们的研究为理解环境粒度的变化如何影响在自然中经历可变营养质量的消费者提供了一个机制基础。
