|| 要旨トップ | 本企画の概要 |||日本生態学会第70回全国大会 (2023年3月、仙台) 講演要旨
シンポジウム S02-4 （Presentation in Symposium）
Reciprocal interactions between plants and soil microbes (i.e., plant-soil feedback, PSF) are increasingly recognized as a process structuring plant communities. However, as the impacts soil microbes have on plants vary greatly across different systems, it is challenging to integrate results into a general predictive framework. Moreover, current theories also assume simplified microbial dynamics and constant interaction strengths between plants and soil microbes, overlooking the temporal complexity embedded within plant-soil microbe interactions. In this talk, I will first show how we can use the concepts of stabilizing (i.e., increasing species’ niche differences) and equalizing (i.e., decreasing species’ competitive hierarchies) from modern coexistence theory to contextualize the diverse effects of soil microbes on plant coexistence. I will also discuss how one can employ experimental designs inspired by modern coexistence theory to study microbe-mediated plant coexistence. In the second part, I will focus on how the temporal dimensions of PSF regulate the pathways through which soil microbes influence plant competitive outcomes. With a patch occupancy model, I show that the conditioning and decay rates of PSF, as well as the specific plant demographic transition affected by soil microbes, predict whether soil microbes act primarily as stabilizing or equalizing forces. Finally, I will introduce an experiment that quantifies how the decay of PSF affects plant coexistence in an annual plant community. Preliminary results suggest that incorporating a decay phase during which the conditioned soils are covered by dead plant material and exposed to a prolonged drought, thereby mirroring the system's characteristics, may provide a more realistic understanding of how soil microbes operate in nature. Taken together, I demonstrate how we can work towards a framework to predict the outcomes of plant-soil microbe interactions in their natural context.