Effects of Soil Conditioning by Bromus tectorum on Decomposition Rates of Plant Litter and Soil Properties

Lyon, Hayley M.

Undergraduate Honors Thesis

Effects of Soil Conditioning by Bromus tectorum on Decomposition Rates of Plant Litter and Soil Properties Public Deposited

Analytics

Citations

Citeable URL: https://scholar.colorado.edu/concern/undergraduate_honors_theses/4j03d037c

Abstract

Cheatgrass (Bromus tectorum) is a thoroughly studied invasive species worldwide that possesses multiple characteristics that have allowed it to become a highly competitive invader. Understanding the mechanisms that allow cheatgrass to dominate so many plant communities is an ongoing area of research. One area of current research is analyzing how cheatgrass is able to alter soil characteristics, and how altering those characteristics affects production and decomposition of plant litter by both native and invasive species. My research follows current research inquiries by looking at how decomposition of plant litter is affected by altered soil characteristics. A laboratory study was performed to determine decomposition rates of cheatgrass litter on soils from native grass and cheatgrass sites under constant temperature and moisture conditions. A field study was also performed to determine and compare decomposition rates of cheatgrass litter and a native plains cottonwood (Populus deltoides monilifera) on both native grass and cheatgrass soil sites. The results from my study were interpreted in the context of the soil microbial communities using data provided by other studies. My results indicated that litter from native plants is insensitive to the altered cheatgrass environment, while cheatgrass litter decomposes at a significantly slower rate on its own altered soil than on unaltered native soil. These data indicate that cheatgrass experiences a negative home field advantage (HFA) on its own soil. The fact that plains cottonwood was insensitive to the cheatgrass soil but that cheatgrass decayed more slowly on its own soil suggests the soil microbial community generated by the chemical composition of cheatgrass litter is different and not as efficient in processing this substrate.

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