ARS | Publication request: THE EFFECTS OF FIRE AND LIVESTOCK GRAZING ON GRASSHOPPER POPULATION DYNAMICS: AN ONGOING INVESTIGATION

Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 2, 2003
Publication Date: January 24, 2004
Citation: Branson, D.H. and G.A. Sword. 2004. The effects of fire and livestock grazing on grasshopper population dynamics: An ongoing investigation. Society for Range Management Abstracts 57:45.

Technical Abstract: Habitat management practices such as burning or livestock grazing have the potential to influence grasshopper population dynamics. A recent study suggests that habitat manipulation in the form of grazing management can reduce grasshopper populations on rangeland in the northern Great Plains. Fire can also affect grasshoppers in numerous ways, but investigations of its effects on rangeland grasshopper population dynamics in the northern Great Plains are limited. No long term replicated studies have examined the separate and interactive effects of fire and grazing on grasshopper population dynamics and vegetation. We sampled grasshopper population densities and community composition in all possible combinations of burning (burn and no-burn) and grazing treatments (twice-over rotational, season-long and no grazing). The 3 replicate blocks in the study are distinct grazing allotments on the USFS Little Missouri National Grassland in western North Dakota. Baseline sampling was conducted at all sites in 2001 prior to the initiation of grazing and burning treatments. Grazing treatments were initiated in the summer of 2002 and burning was conducted in October 2002. Few differences in grasshopper population densities or species composition between grazing treatments were evident in 2002. Grasshopper population densities were lower in all treatment combinations during 2003. Changes in plant community structure that might impact grasshopper population dynamics are not likely to occur immediately. In addition, the effects of grazing management on grasshopper population dynamics may be evident only during periods with high grasshopper population densities.