title: An experimental analysis of grasshopper community responses to fire and livestock grazing in a northern mixed-grass prairie.
abstract: The outcomes of grasshopper responses to both vertebrate grazing and fire vary across grassland ecosystems, and are strongly influenced by local climactic factors. Thus, the possible application of grazing and fire as components of an ecologically based grasshopper management strategy  must be investigated in regional studies. In this study, we examined the effects of grazing and fire on grasshopper population density and community composition in a northern Great Plains mixed-grass prairie. We employed a large-scale, replicated, and fully-factorial manipulative experimental  design across 4 yr to examine the separate and interactive effects of three grazing systems in burned and unburned habitats. Grasshopper densities were low throughout the 4-yr study and 1 yr of pretreatment sampling. There was a significant fire by grazing interaction effect on cumulative  density and community composition, resulting from burned season long grazing pastures having higher densities than unburned pastures. Shannon diversity and grasshopper species richness were significantly higher with twice-over rotational livestock grazing. The ability to draw strong conclusions  regarding the nature of species composition shifts and population changes in the presence of fire and grazing is complicated by the large site differences and low grasshopper densities. The results reinforce the importance of long-term research to examine the effects of habitat manipulation  on grasshopper population dynamics.
authors.affiliation: United States Department of Agriculture-Agricultural Research Service, Northern Plains Agricultural Research Laboratory, Sidney, MT 59270, USA. dave.branson@ars.usda.gov
authors.forename: David H
authors.initials: DH
authors.lastname: Branson
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Sword
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D058448:Biota; D005390:Fires; D006110:Grasshoppers / Q000502:physiology*; D009658:North Dakota; D011156:Population Density