Painter and Belsky used Agropyron smithii and Bouteloua gracilis plants, from intensively grazed prairie dog (Cynomys ludovicianus) colonies and from a grazing exclosure in South Dakota, to compare responses of conspecific populations with different histories of exposures to grazing and to competition for light. Defoliation more often adversely affected exclosure plants than colony plants, while interpopulation competition more often adversely affected colony plants. Results indicate that conclusions based on studies of plants in long-term exclosures may not apply to plant populations having long histories of intensive grazing. While there were differences between species, in both, these experiments provided evidence of population differentiation, resulting in morphologically dissimilar populations which responded differently to defoliation and to inter- and intrapopulation competition.
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.