Code for "Biotic resistance to cheatgrass is highest in plant communities with herbaceous perennial cover and stress-tolerant leaf traits"
Year: 2026
Type: dataset
Abstract: Managing invasive plant species requires the identification of plant community characteristics that confer biotic resistance. Theory predicts that resident species can resist invasion via limiting similarity, with high trait similarity resulting in competitive exclusion of invaders, or via stress tolerance, with conservative traits that limit invasion by keeping resources at low levels. It remains unclear which resident community characteristics are most effective for promoting biotic resistance to invasion and how we should quantify characteristics to test these theories. In this study, we conducted a large, distributed experiment in plant communities where invasive cheatgrass (Bromus tectorum) occurs to determine the relative importance of limiting similarity and stress tolerance for conferring biotic resistance. We planted individual cheatgrass seeds at 42 sites across western North America, recorded individual-level fecundity, visually estimated resident species cover around planted cheatgrass, and quantified resident community traits using data from the TRY and BIEN databases. We used three lines of evidence to test these theories: functional group composition, community-weighted mean traits, and functional distance in principal component analyses. We found strong support for the stress tolerance hypothesis and no support for the limiting similarity hypothesis – the resident plants that most strongly suppressed cheatgrass were well-adapted to persistence in stressful climates and low resource soils, not those most functionally similar to cheatgrass. Of the resident functional groups, perennial grass cover was strongly associated with reduced cheatgrass fecundity, but interestingly, perennial forb cover also had a strong negative relationship with fecundity. Our functional trait analyses showed that cheatgrass fecundity was lower near neighbors with stress-tolerant, slow-growing leaves (low leaf nitrogen, high leaf dry matter content). As neighborhood functional distance increased, cheatgrass fecundity decreased, indicating evidence against the limiting similarity hypothesis. Our model comparison revealed that, in practice, functional group data alone can be useful for predicting resistance to cheatgrass. In sum, communities with high herbaceous perennial cover and conservative leaf traits were associated with biotic resistance, supporting the stress tolerance hypothesis. Promoting plant communities with stress-tolerant perennial grasses and forbs may slow cheatgrass invasion in western North America.
Source: Figshare
Authors: Annie Schiffer, Lauren Porensky, Dana Blumenthal, Lina Aoyama, Madelon F. Case, Michael Otis Clyne, Stella Copeland, Sage L. Ellis, David J. Ensing, Martin Genova, Matthew Germino, Richard A. Gill, April Goebl, Mevin Hooten, Jesse R Lasky, Toby M. Maxwell, Chandra E. Moffat, Rebecca A. Nelson, Rory O'Connor, Brooke B. Osborne, Jacqueline P. Ott, Lisa J. Rew, Eugene W. Schupp, Robert K. Shriver, Samuel B. St. Clair, Amy J. Symstad, Alexandra K. Urza, Megan Vahsen, Peter B Adler
Language: English
Subfield: Nature and Landscape Conservation
Field: Environmental Science
Domain: Physical Sciences
SDG: Life on land
Open Access status: green
OpenAlex ID: W7165129173