Bison grazing ecology at the Rocky Mountain Arsenal National Wildlife Refuge, Colorado

Open-File Report 2013-1112
By: , and 



The Rocky Mountain Arsenal (RMA) National Wildlife Refuge reintroduced bison to a small pasture in 2007. Refuge managers needed information on the effects of bison grazing on vegetation communities in the bison pasture as well as information on how bison might affect other management priorities at RMA. In particular, RMA managers were interested in bison grazing effects on vegetation productivity, amount of vegetation utilization by bison, and habitat selection by bison to inform RMA herd managers and for potential expansion of bison range on the refuge. In 2007, U.S. Geological Survey (USGS) designed a study to investigate bison grazing effects through measurement of vegetation in the 600-hectare enclosure where the bison are currently pastured. This research was a collaborative effort between USGS and RMA refuge staff and had active field components in 2007 and 2010. We found that the effects and intensity of bison grazing on vegetation in the RMA bison pasture is linked to prairie dog presence. Where both species were present, they were removing a significant amount of biomass compared to areas where only bison were present. Also, prairie dogs appeared to enhance the greater production of native forbs, but we were not able to identify the mechanism for this increased production. We were not able, however, to generate an accurate vegetation map for the bison pasture, and this limited our ability to achieve the level of statistical precision necessary to identify grazing impacts and habitat selection of bison.

Study Area

Publication type Report
Publication Subtype USGS Numbered Series
Title Bison grazing ecology at the Rocky Mountain Arsenal National Wildlife Refuge, Colorado
Series title Open-File Report
Series number 2013-1112
DOI 10.3133/ofr20131112
Year Published 2013
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Fort Collins Science Center
Description v, 20 p.
Country United States
State Colorado
Other Geospatial Rocky Mountain Arsenal National Wildlife Refuge
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details