Rangeland Ecology & Management

Get reliable science

PATTERNS OF CHEATGRASS (BROMUS TECTORUM) INVASION IN THE NORTHERN GREAT PLAINS.
Author
Ozeran, Rebecca
Carr, Craig
Maxwell, Bruce
Olson, Bret E.
Publisher
Society for Range Management
Publication Year
2016
Body

Cheatgrass (Bromus tectorum), is an invasive, exotic annual grass found throughout North America. Cheatgrass has been extensively studied in the Great Basin region of North America where the majority of precipitation comes in winter and early spring, and the vegetation consists primarily of cool-season species. However, relatively little research has been done in the Northern Great Plains region where most precipitation comes in spring and summer, supporting a mixture of cool- and warm-season plant species. As climate and vegetation differ between the Northern Great Plains and the Great Basin, the ecological impacts of cheatgrass in the Northern Great Plains are unknown. In order to better understand cheatgrass ecology in this region, we created a study to assess cheatgrass invasion and abundance in the distinct climate of the Northern Great Plains. Fifteen study plots were established at each of two ranches in Montana, both of which are owned and operated by the Montana Agricultural Experiment Station: Thackeray Ranch, southeast of Havre, MT, and Red Bluff Ranch, east of Norris, MT. Within these plots we examined relationships among cheatgrass abundance, biotic and abiotic site characteristics (e.g. species diversity, aspect, ecological site description), and disturbance indicators (e.g. livestock fecal counts) in 2014 and 2015. An initial generalized linear mixed-effects regression model was reduced to simpler models by comparing the Aikake's Information Criterion (AIC) for each fitted model, and selecting for lower AIC to best predict cheatgrass abundance. Based on these models, site characteristics such as aspect and ecological site within the context of known disturbance may be important predictors that land managers in the Northern Great Plains could use to estimate the risk of cheatgrass invasion or dominance on the landscapes they manage.

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Corpus Christi, TX