Mycorrhizal symbioses influence the trophic structure of the Serengeti

作者：Bo Stevens, Jeffrey Propster, Gail W. T. Wilson, Andrew J. Abraham, Chase Ridenour, Christopher E. Doughty, Nancy Collins Johnson · 发表于：Journal of Ecology · 年份：2018 · DOI：10.1111/1365-2745.12916 · 被引用次数：24 · 研究领域：Mycorrhizal Fungi and Plant Interactions、Forest Ecology and Biodiversity Studies、Ecology and Vegetation Dynamics Studies

Abstract It is known that tropical grasslands such as Serengeti host large populations of arbuscular mycorrhizal ( AM ) fungi and that they respond to abiotic and biotic factors. It is also known that AM symbioses are important for the uptake of essential plant nutrients, which, in turn, influences the biomass and nutritional quality of herbivores and their predators. The purpose of this study was to investigate the influence of AM symbioses on the biomass of different trophic levels of an ecosystem. To do this, we first measured the neutral lipid fatty acid biomarker 16:1ω5 to estimate the biomass of AM fungi in a long‐term grazing exclusion experiment. Then, we used model selection of Bayesian linear regressions to infer the primary factors that influence AM fungal biomass. Using model selection of different combinations of soil characteristics, we selected the best model using the leave‐one‐out cross‐validation information criterion. Finally, we used the Madingley model to simulate the influence of AM fungi on higher trophic levels. We combined spatially explicit information about soil phosphorus and AM fungal biomass to explore the emergent patterns of the Serengeti resulting from AM symbioses. Our Bayesian analysis indicated that total soil phosphorus was the strongest predictor of AM fungal biomass, and there were significant interactions with grazing. Arbuscular mycorrhizal fungal biomass is lowest in soil where phosphorus is limited and increases with increasing phosp...