A synthesis of the effects of cheatgrass invasion on U.S. Great Basin carbon storage

Non-native, invasive Bromus tectorum (cheatgrass) is pervasive in sagebrush ecosystems in the Great Basin ecoregion of the western U.S., competing with native plants and promoting more frequent fires. As a result, cheatgrass invasion likely alters carbon (C) storage in the region. Many studies have measured C pools in one or more common vegetation types: native sagebrush, invaded sagebrush, and cheatgrass-dominated (often burned) sites, but these results have yet to be synthesized.

We performed a literature review to identify studies assessing the consequences of invasion on C storage in aboveground biomass (AGB), belowground biomass (BGB), litter, organic soil, and total soil. We identified 41 articles containing 386 unique studies and estimated C storage across pools and vegetation types and used linear mixed models to identify the main predictors.

We found consistent declines in biomass C with invasion: AGB C was 55% lower in cheatgrass (40 ± 4 g C m-2) than in native sagebrush...