Competition between alien annual grasses and native annual plants in the Mojave Desert
Alien annual grasses in the genera Bromus and Schismus are widespread and abundant in the Mojave Desert, and negative correlations between these aliens and native annual plants suggest that competition may occur between them. Effects of competition were evaluated by thinning alien annual grass seedlings and measuring the responses of native annual plants at three sites in the central, southcentral and southwestern Mojave Desert during 2 y of contrasting plant productivity. Effects ofBromus and Schismus were evaluated separately in the microhabitat where each was most abundant, beneath the north side of creosote bushes (Larrea tridentata) for Bromus and in the open interspace between shrubs for Schismus. Thinning of Bromus and Schismus significantly increased density and biomass of native annuals at all three sites, only during a year of high annual plant productivity and species richness. Effects of thinning were greatest for Amsinckia tesselata and for a group of relatively uncommon native annuals. Thinning also significantly increased the density and biomass of the alien forb, Erodium cicutarium. These results show that alien annual grasses can compete with native annual plants and an alien forb in the Mojave Desert and that effects can vary among years.
Citation Information
Publication Year | 2000 |
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Title | Competition between alien annual grasses and native annual plants in the Mojave Desert |
DOI | 10.1674/0003-0031(2000)144[0092:CBAAGA]2.0.CO;2 |
Authors | Matthew L. Brooks |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | American Midland Naturalist |
Index ID | 1007887 |
Record Source | USGS Publications Warehouse |
USGS Organization | Western Ecological Research Center |