The 19,000-acre Bison Range on the Flathead Indian Reservation is the traditional homeland of the Confederated Salish and Kootenai Tribes. Here, the Salish, Kootenai, and Pend d’Oreilles tribes have focused on land restoration, soil health improvement, and invasive species containment in response to climate change. Invasive annual grasses, particularly Ventenata dubia, pose significant threats to native grasses on this Montana range.
Invasive vegetation and grazing together impact climate change and soil health. Bison do graze this land; however, the cumulative effects of exotic annual grasses and bison grazing influence the resilience of rangeland ecosystems in complex ways, and little is understood about these interactions.
Sarah Holloway, Salish Kootenai College graduate student, and her adviser were exploring research projects that would involve rangeland restoration. They realized that they first needed a baseline that would indicate soil health in various grassland microsites.
As they held conversations with the Bison Range’s rangeland ecologist, they fine-tuned their ideas toward researching the relationship among bison grazing, invasive vegetation, and soil health on the reservation’s land.
Reflecting on the process, Holloway says “It is exciting to take ideas from the scratch board to the field.”
The research explores soil organic carbon, infiltration rates, and bulk density at two sites with three vegetation functional groups. The groups are being mapped and sampled using the line-point intercept method. One site has a long history of bison grazing while the other nearby site is in an exclosure.
“Our hope is that the tribes will look at our results and use them as a baseline. We’re not providing prescriptive recommendations but want to share what impacts we are seeing now. It is a stepping off point for future management,” says Holloway.