How do exotic species invasions enhance our understanding of how rare plants persist?
Levine, Jonathan*,1, Rees, Mark2, 1 University of California, Santa Barbara, CA, USA2 Imperial College at Silwood Park, Ascot, Berks, United Kingdom ABSTRACT- Habitats dominated by exotic species present the opportunity to examine rare species persistence in competitive environments. Coexistence models from community ecology suggest that for species with dormancy, environmental fluctuations may be essential for persistence in invaded habitats. We developed stochastic models based on California grasslands to examine the effects of annual rainfall fluctuations on the persistence of endangered annual plants competing with exotic grasses. We found that in multispecies models, despite both types of species being favored by the same high rainfall environments, differences in germination biology and dormancy caused the rare annual plants to perceive variation in their environment differently than their exotic grass competitors. This allowed the rare plants to benefit from annual fluctuations
