Disturbance is more important than seeding or grazing in determining soil communities

New research conducted by UArizona researchers shows that disturbance is more important than seeding or grazing in determining soil communities.

A primary goal of aridland grassland management is often to enhance ecosystem services and processes (such as forage production or erosion control). Soil, while often ignored in plant management, supports diverse communities of organisms (such as bacteria and fungi) and is critical for the maintenance of healthy arid ecosystems. For example, soil microbial communities can limit plant production, enhance (or restrict) invasive plant dominance and modify the capacity of the soil to hold onto water. Recent work at the University of Arizona investigated the impact of common management approaches after major disturbance on soil microbial communities. The researchers looked at how seeding and livestock grazing affected plant communities, soil microorganisms, and soil fertility 3 years after the restoration of a disturbed pipeline corridor in southeastern Arizona. They found that initial soil disturbance and topsoil treatment, regardless of seeding or grazing, was the most influential factor in determining differences in both plant and microbial communities. Compared with the control (no disturbance and no seeding), the disturbed and restored sites had greater plant species richness, greater total herbaceous plant cover, greater soil organic matter, higher pH, and differed in soil nutrients. The undisturbed control had a smaller proportion of bacterial functional groups associated with the breakdown of plant biomass and a smaller proportion of arbuscular mycorrhizal fungi (AMF) compared with disturbed and restored sites. The ability of the unseeded disturbed site to recover robust vegetation may be due in part to the high presence of AMF. These differences show selection for soil microorganisms that thrive in disturbed and restored sites and may contribute to increased plant productivity. Restoration of specific plant species or ecological processes and services would both benefit from better understanding of the impacts of disturbance on soil microorganisms and soil fertility.

The paper can be found here: https://onlinelibrary.wiley.com/doi/full/10.1111/rec.13156?casa_token=_D6ncaWKDNIAAAAA%3APZnY1d5U8CXAeCxtkjnmTfqmwlP2Z3c3fAZhMDbF6X8XU9zQ3BNCOOyfCvBqO1uOxQbTJNgPZy5hzg

Any questions? Feel free to reach out to Elise at egornish@email.arizona.edu