| Abstract: | Abundance of invasive plants is often attributed to their ability ot outcompete native species. We compared resource acquisition and allocation of the invasive annual grass Bromus madritensis subsp. rubens with that of two native Mojave Desert annuals, Vulpia octoflora and Descurainia pinnata, in a glasshouse experiment. Each species was grown in monoculture at two densities and two levels of N availability to compare how these annuals capture resources and to understand their relative sensitivities to environmental change. During >4 mo of growth, Bromus used water more rapidly and had greater biomass and N content than the natives, partly because of its greater root-surface area and its exploitation of deep soils. Bromus also had greater N uptake, net assimilation and transpiration rates, and canopy area than Vulpia. Resource use by Bromus was less sensitive to changes in N availability or density than were the natives. The two native species in this study produced numerous small seeds that tended to remain dormant, thus ensuring escape of offspring from unfavorable germination conditions; Bromus produced fewer but larger seeds that readily germinated. Collectively, these traits give Bromus the potential to rapidly establish in diverse habitats of the Mojave Desert, thereby gaining an advantage over coexisting native species. |
| Genre: | Article |
| ProdID: | 70025837 |
| Citation Author: | DeFalco, L. A.; Bryla, D. R.; Smith-Longozo, V.; Nowak, R. S. |
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| Citation End Page: | 1053 |
| Citation Issue: | 7 |
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| Citation Language: | English |
| Citation Larger Work Title: | American Journal of Botany |
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| Citation Number Of Pages: | 9 |
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| Citation Search Results Text: | Are Mojave Desert annual species equal? Resource acquisition and allocation for the invasive grass Bromus madritensis subsp. rubens (Poaceae) and two native species; 2003; Article; Journal; American Journal of Botany; DeFalco, L. A.; Bryla, D. R.; Smith-Longozo, V.; Nowak, R. S. |
| Citation Start Page: | 1045 |
| Citation Volume: | 90 |
| Citation Year: | 2003 |
| Type: | citation/reference |
| Text: | Are Mojave Desert annual species equal? Resource acquisition and allocation for the invasive grass Bromus madritensis subsp. rubens (Poaceae) and two native species; 2003; Article; Journal; American Journal of Botany; DeFalco, L. A.; Bryla, D. R.; Smith-Longozo, V.; Nowak, R. S. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Wed, 1 Jan 2003 00:00 -0600 |
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