When herbivores preferentially feed on early successional species they may generate conditions favorable for these species and thus create a positive feedback. Positive feedbacks may create multiple stable equilibria within plant communities. This study demonstrates the presence of these positive feedbacks using experiments conducted in a restored California grassland. Results showed that pocket gophers (Thomomys bottae) preferentially forage in areas dominated by annual species, and gopher foraging activity increases the abundance of annual plants. The authors used a Markov chain model to identify how the foraging behavior, dispersal behavior, and population dynamics of territorial herbivores can structure a plant community across multiple spatial scales. If juveniles are selective when searching for territories during their dispersal phase, then herbivores can also generate persistent and distinct plant communities over larger spatial scales. In this case, fixed regions of the landscape may become occupied by herbivores for long periods and be composed of a range of successional plant species, whereas the remaining landscape is abandoned by herbivores and becomes dominated by late successional species.
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.