Competition and Other Barriers to Establishment of a Native Perennial Grass (Elymus elymoides) in Alien Annual Grass (Bromus tectorum) Communities
Document Type
Article
Journal/Book Title/Conference
Journal of Arid Environments
Volume
58
Publication Date
2004
First Page
405
Last Page
422
Abstract
The alien grass Bromus tectorum dominates stable annual-plant communities that have replaced native shrub-perennial grass communities over much of the semi-arid western United States. We conducted field competition experiments between B. tectorum and a native grass, Elymus elymoides, on two sites to determine the effects of B. tectorum competition on perennial grasses, and the role of B. tectorum competition in the stability of B. tectorum-dominated communities. B. tectorum competition acting on seedling-stage E. elymoides plants greatly reduced first-year relative growth rates and biomass which, in turn, reduced second-year survival, biomass, and flowering. However, B. tectorum competition acting on older E. elymoides plants had much less effect, which may help to explain why intact perennial-plant communities are resistant to B. tectorum invasion. At the drier site, direct effects of B. tectorum competition were less, but competition and drier habitat combined to produce greater E. elymoides mortality.
Recommended Citation
Humphrey, L.D.‡ and E.W. Schupp. 2004. Competition and other barriers to establishment of a native perennial grass (Elymus elymoides) in alien annual grass (Bromus tectorum) communities. Journal of Arid Environments 58: 405–422.
