Reclamation efforts are aimed at restoring ecosystem structure and function through reestablishment of desirable vegetation. Many restoration efforts focus only on monitoring vegetation response, although soil microbial communities can affect an ecosystem and may be an important factor when considering recovery. Response of soil microbial communities to herbicides is not well documented. A study on reclamation options including seeding desirable species and herbicide application to control weeds was conducted. Our objective was to evaluate the effects of various herbicides and the resulting plant cover on soil microbiota in a reclamation setting. Soil samples (top 10 cm) were collected from each herbicide treatment at one field site in mid-August 2012 after late summer precipitation, following a dry spring and summer. Samples were analyzed using a modified Bligh-Dyer methodology of phospholipid fatty acid analysis which gives an estimate of relative abundance after which microbial signatures were grouped into functional types. Herbicides had no effect on microbial communities. Regressions showed some significant positive relationships between annual forb cover and saprotrophic and protozoa populations (p<0.05). However, increases in microbial abundances of those groups were very small, roughly 0.1 ug fatty acid per g soil difference. Regression of perennial grass and microbial population showed no relationship at an alpha of 0.05. However, AM fungi regressed with perennial grass had a p=0.0665, indicating a slight positive biological association. Microbial activity is greatest when moisture levels are higher, so it is possible that some herbicide and microbial effects were not observable because of the late season sampling.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.