The purpose of this research in Oklahoma was to analyze the effect of grazing on the growth and morphology of vesicular-arbuscular mycorrhizal (VAM) fungi and non-vesicular-arbuscular mycorrhizal (non-VAM) grasses, in a native mixed grass prairie. Grasses were grazed by a mixture of different herbivores, primarily bison, moving freely between the three study sites. The interaction of severe drought and grazing was significantly detrimental to plant growth in this study. Only one species, Schizachyrium scoparium, showed little response to either factor. Grazing significantly reduced plant size in all the other grass species. Mychorrhizal colonization had no effect upon plant growth rates or size. Even in grazed plots, where nutrient content and soil moisture were higher, no mycorrhizal effect on plant growth was observed. Grazing did not influence VAM colonization, although grazed plants, which were growing in non-fumigated soil, had significantly lower colonization levels than any other treatment.
Citations and enhanced abstracts for journals articles and documents focused on rangeland ecology and management. RSIS is a collaboration between Montana State University, University of Idaho, and University of Wyoming.