Institute of Biochemistry and Biology, Theoretical Aquatic Ecology and Ecophysiology, University of Potsdam, Am Neuen Palais 10, 14469, Potsdam, Germany.
Limnological Institute, University of Konstanz, Mainaustrasse 252, 78464, Konstanz, Germany.
Sci Rep. 2017 Sep 8;7(1):11035. doi: 10.1038/s41598-017-11183-3.
Biodiversity can strongly influence trophic interactions. The nutritional quality of prey communities and how it is related to the prey diversity is suspected to be a major driver of biodiversity effects. As consumer growth can be co-limited by the supply of several biochemical components, biochemically diverse prey communities should promote consumer growth. Yet, there is no clear consensus on how prey specific diversity is linked to community biochemical diversity since previous studies have considered only single nutritional quality traits. Here, we demonstrate that phytoplankton biochemical traits (fatty acids and sterols) can to a large extent explain Daphnia magna growth and its apparent dependence on phytoplankton species diversity. We find strong correlative evidence between phytoplankton species diversity, biochemical diversity, and growth. The relationship between species diversity and growth was partially explained by the fact that in many communities Daphnia was co-limited by long chained polyunsaturated fatty acids and sterols, which was driven by different prey taxa. We suggest that biochemical diversity is a good proxy for the presence of high food quality taxa, and a careful consideration of the distribution of the different biochemical traits among species is necessary before concluding about causal links between species diversity and consumer performance.
生物多样性可以强烈影响营养关系。猎物群落的营养质量及其与猎物多样性的关系被怀疑是生物多样性效应的主要驱动因素。由于消费者的生长可能受到多种生物化学成分供应的共同限制，生物化学成分多样的猎物群落应该会促进消费者的生长。然而，由于之前的研究只考虑了单一的营养质量特征，因此对于猎物特定多样性与群落生物化学成分多样性之间的联系还没有明确的共识。在这里，我们证明了浮游植物的生物化学成分特征（脂肪酸和甾醇）在很大程度上可以解释大型溞的生长及其对浮游植物物种多样性的明显依赖。我们发现浮游植物物种多样性、生物化学成分多样性和生长之间存在很强的相关性证据。物种多样性与生长之间的关系部分可以解释为，在许多群落中，长链多不饱和脂肪酸和甾醇限制了大型溞的生长，而这是由不同的猎物类群驱动的。我们认为，生物化学成分多样性是高质量食物类群存在的良好指标，在得出物种多样性与消费者表现之间存在因果关系的结论之前，有必要仔细考虑不同物种之间不同生物化学成分特征的分布。
