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ARS Home » Plains Area » Sidney, Montana » Northern Plains Agricultural Research Laboratory » Pest Management Research » Research » Publications at this Location » Publication #242239
Title: Coevolution between Native and Invasive Plant Competitors: Implications for Invasive Species Management

Author
item LEGER, ELIZABETH - University Of Nevada
item Espeland, Erin

Submitted to: Evolutionary Applications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2009
Publication Date: 1/25/2010
Citation: Leger, E.A., Espeland, E.K. 2010. Coevolution between Native and Invasive Plant Competitors: Implications for Invasive Species Management. Evolutionary Applications. 3(2): 169–178.

Interpretive Summary: Invasive plants may be able to spread because they take resources away from native plants. When invasives grow larger on less water and soil nutrients than natives, they effectively outcompete natives. In order to continue to dominate landscapes, the competitive advantage of invasives must be persistent. Native species remain in the landscape after highly invasive species are introduced may be able to compete with invasive species for resources. When population sizes and genetic diversity are large enough in native species, they may be able to evolve even better competitive abilities. Native species could even evolve to become significant competitors with invasive species, thus reducing their impact. Invasive species may be able to respond in turn, creating an evolution-driven one-upmanship between these two competing groups. We discuss how simple demography (population size and growth rates) and population genetic processes (gene flow, genetic diversity, and natural selection) may affect the ability of native and invasive species to evolve competitive ability against one another. We discuss how native and invasive plants have intrinsically different demographic and population genetic processes, and we discuss how this difference might affect their rates of evolution and ability to evolve. Management actions that maintain genetic diversity in native species while reducing population sizes and genetic diversity in invasive species could promote the ability of natives to evolve competitive ability against invasive species.

Technical Abstract: Invasive species may establish in communities because they are better competitors than natives, but in order to remain community dominants, the competitive advantage of invasive species must be persistent. Native species that are not extirpated when highly invasive species are introduced are likely to compete with invasive species. When population sizes and genetic diversity of native species are large enough, natives may be able to evolve traits that allow them to co-occur with invasive species. Native species may also evolve to become significant competitors with invasive species, and thus affect the fitness of invaders. Invasive species may respond in turn, creating either transient or continuing coevolution between these two competing groups. In addition to demographic factors such as population size and growth rates, a number of factors including gene flow, genetic drift, the number of selection agents, and genetic diversity affect the ability of native and invasive species to evolve competitive ability against one another. We discuss how these factors may differ between populations of native and invasive plants, and how this might affect their ability to respond to selection. Management actions that maintain genetic diversity in native species while reducing population sizes and genetic diversity in invasive species could promote the ability of natives to evolve improved competitive ability.