Soil Microbial Ecology of Remnant Hill Prairies in the Great Rivers Confluence Area: Invasion and Edge Effects

Anthony Yannarell
Assistant Professor of Microbial Ecology
Department of Natural Resources and Environmental Sciences
University of Illinois (Urbana-Champaign)

Summary of soil microbial work done

In June of 2011, 13 remnant hill prairies in Monroe County, IL were sampled as part of a soil microbial ecology research project by Sarah Menning and Tony Yannarell (University of Illinois at Urbana-Champaign). This research was sponsored by the National Great Rivers Research and Education Center, and it was carried out with the invaluable assistance of the members of Clifftop.

The researchers visited 13 prairie patches located in the following areas: Salt Lick Point, Potato Hill, White Rock, Chalfin Bridge, Fults, Zanders-Schaffner, and Angela’s Prairie. In each prairie patch, the researchers established four transects running from the open prairie core and into the surrounding forest. Three soil cores were collected along each transect: one in the open prairie core, one in the shrub-encroached edge of the patch, and one in the forest. The researchers extracted and purified microbial DNA from these samples, and they used this DNA to characterize the soil bacterial and soil fungal communities in each soil core. They also used some of this soil to grow and isolate soil bacteria for identification laboratory analyses.

Initial findings

Soil microbial communities found in the open prairie cores were statistically distinct from those growing in the surrounding forest. However, microbial communities from the shrub-encroached prairie edge were mixtures of both prairie and forest types. Thus, encroachment by shrubs alters soil microbial communities, just as it affects plant communities in these prairies. The researchers also found that prairie patches that are actively managed to maintain high floristic quality have distinctive soil microbial communities in comparison with prairie patches that are overgrown or degraded.

The researchers cultivated over 350 different bacterial isolates from these prairie habitats. They found a number of common soil genera, including Pseudomonas, Bacillus, Duganella, Flavobacterium, Arthrobacter, Micromonospora, Paenibacillus, Streptomyces, and others.

Planned future work

The researchers are interested to know if the microorganisms found in the shrub-encroached edge habitats are responsible for promoting further encroachment or further changes to the plant communities. They would also like to understand how the soil microbial communities change in response to restoration of degraded prairie patches.

A poster representation, compiled by Sarah Menning, that summarizes this work can be viewed here: Soil Microbial Ecology of Remnant Hill Prairies, Sarah Menning.