Jon De Long - Speaker

Plant-soil feedbacks (PSFs) involve changes to the soil wrought by plants, which can alter the biotic and abiotic properties of the soil, in turn affecting the performance of plants that grow in the soil at a later time. The importance of PSFs for understanding ecosystem functioning has been the focus of much recent research, for example, in predicting the consequences for agricultural production, biodiversity conservation, and plant population dynamics, particularly under global climate change. Here, we describe an experiment that was designed to test the effects of PSFs under field conditions. To our knowledge, this is one of the first, large-scale field experiments of its kind. We removed the existent plant community and replaced it with target plant communities that consisted of contrasting grass and forb combinations. This was done in two successive years in two different subplots in order to investigate temporal aspects of soils that were conditioned by the same plant community. We created plant communities that consisted of species that were either “fast” or “slow” growing plants, in accordance with the plant economics spectrum. We choose this well-established paradigm because plants on opposite ends of this spectrum differ have developed contrasting strategies to cope with environmental conditions. This means they intrinsically differ in their feedbacks with soil abiotic and biotic factors. The unique and novel design of this experiment allows us to simultaneously test for the impacts of temporal effects, plant community composition and plant growth strategy on PSFs. Here, we present the experimental design and the preliminary ecosystem responses to the treatments (i.e., respiration, decomposition, soil microbial communities). Advancing our understanding of how the strength and direction of PSFs vary at the community level under natural field conditions is critical to better predicting ecosystem function and initiating more successful restoration.
12 Sep 2018

ID: 9407897