Improving Cheatgrass and Japanese brome management on Montana range, pasture, and CRP lands by integrating chemical and biological control

The invasion of Bromus tectorum (cheatgrass) can be considered one of the most significant plant invasions in North America, given its magnitude, negative impacts on both nutrient cycling and native species, and its alteration of local fire regimes. As a winter annual, cheatgrass tends to favor the climatic conditions of arid or semi-arid environments, which receive the majority of precipitation during the winter and spring months. Consequently, cheatgrass invasion and control has become a large concern for the Intermountain West, northern Rockies, and northern Great Plains. 

My research focuses on management options for cheatgrass, including chemical control with herbicides, and biocontrol, with Pyrenophora semeniperda, a fungal pathogen that inhibits seed germination. The main purpose of this research is to investigate causes of variation in herbicide efficacy, especially that of imazapic. Specifically, imazapic efficacy will be compared at different application rates and timings and in the presence/absence of plant litter.  I am conducting field studies to look at plant community response to imazapic treatments and greenhouse bioassays to understand herbicide degradation over time.

A similar research project investigates integrated management using chemical control (imazapic) and biocontrol (Pyrenophora semeniperda). This research will be conducted in the greenhouse and will test the effects of cheatgrass litter and timing of simulated precipitation events under chemical, biological, and chemical + biological management strategies.

Ideally, my research will reveal a greater understanding of traditional and novel control strategies that are easily implemented and provide successful control of this insidious invasive. With my research I hope to fill in the gaps of knowledge that exist concerning cheatgrass, aiding Montana and other regions of the West in developing more effective management strategies.

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