Undergraduate Honors Theses

Thesis Defended

Fall 2011

Document Type



Environmental Studies

First Advisor

Timothy Seastedt

Second Advisor

Dale Miller

Third Advisor

William Browman


The exotic grass, Bromus tectorum, commonly known as cheatgrass, is a highly damaging, ubiquitous invader. Cheatgrass has proven to be a very proficient competitor, frequently forcing out native plants, forming monocultures and reducing biodiversity in the landscape which they invade. This experiment tested the importance of soil conditioning on the growth and dominance of cheatgrass. Productivity of Bromus tectorum and a native grass, Pascopyrum smithii, were compared by harvesting aboveground biomass after two simulated growing seasons in combinations of invaded and native conditioned soils. These preconditioned soils were gathered from monocultures found on the Colorado Front Range. Results indicated that Bromus tectorum does not inhibit the productivity of natives and shows signs of increasing its own fertility. Future research should examine the specific mechanisms that cheatgrass may employ to alter soil properties.