Department of Ecology, Evolution and Behavior, University of Minnesota, Twin Cities, Minnesota, USA.
Department of Plant Pathology, University of Minnesota, Twin Cities, Minnesota, USA.
Ecol Lett. 2019 Apr;22(4):707-716. doi: 10.1111/ele.13232. Epub 2019 Feb 12.
Theory predicts that consumers may stabilise or destabilise plant production depending on model assumptions, and tests in aquatic food webs suggest that trophic interactions are stabilising. We quantified the effects of trophic interactions on temporal variability (standard deviation) and temporal stability (mean/standard deviation) of grassland biomass production and the plant diversity-stability relationship by experimentally removing heterotrophs (large vertebrates, arthropods, foliar and soil fungi) from naturally and experimentally assembled grasslands of varying diversity. In both grassland types, trophic interactions proportionately decreased plant community biomass mean and variability over the course of 6 years, leading to no net change in temporal stability or the plant diversity-stability relationship. Heterotrophs also mediated plant coexistence; their removal reduced diversity in naturally assembled grasslands. Thus, herbivores and fungi reduce biomass production, concurrently reducing the temporal variability of energy and material fluxes. Because of this coupling, grassland stability is robust to large food web perturbations.
理论预测，消费者可能会根据模型假设稳定或破坏植物的生产，并且水生食物网的测试表明，营养相互作用是稳定的。我们通过实验从自然和实验组装的不同多样性的草原中去除异养生物（大型脊椎动物、节肢动物、叶片和土壤真菌），量化了营养相互作用对草原生物量生产的时间变异性（标准差）和时间稳定性（均值/标准差）以及植物多样性-稳定性关系的影响。在这两种草原类型中，营养相互作用在 6 年的时间内按比例降低了植物群落生物量的均值和变异性，导致时间稳定性或植物多样性-稳定性关系没有净变化。异养生物也介导了植物共存；它们的去除减少了自然组装的草原中的多样性。因此，食草动物和真菌减少生物量的产生，同时减少能量和物质通量的时间变异性。由于这种耦合，草原的稳定性对大型食物网干扰具有很强的鲁棒性。
