Title of Oral/Poster Presentation

Transient Dynamics, Life History, and Biological Invasions

Class

Article

Department

Wildland Resources

Faculty Mentor

David Koons

Presentation Type

Oral Presentation

Abstract

The ecological and economic costs of biological invasions create a pressing need to predict species' invasive potential. Traditional invasion analyses focus on factors that influence long-term population dynamics, and thus, the ability for invading populations to persist in novel environments. However, short-term (transient) population dynamics following species introductions may greatly influence population susceptibility to demographic stochasticity. We used published matrix population models to simulate the dynamics of small populations for 84 plant species spanning a range of life histories. From demographic simulations, we estimated the effect of transient and long-term dynamics on invasion success (i.e., population viability) for each species and identify the life history correlates of these dynamics. Transient and long-term population growth rates were positively but independently correlated with population viability across species. The minimum population density attained en route to a stable stage structure was the best transient predictor of population viability, suggesting that avoidance of severe short-term population declines is critical for establishment. Species with high fecundity had disproportionately high transient densities and higher long-term population growth rates. Together, these results suggest that highly fecund species are better equipped to overcome the early effects of demographic stochasticity in the establishment phase than less fecund species and help explain the common empirical finding that species invasiveness is correlated with fecundity. Transient and long-term population dynamics are independent axes of demographic performance that influence the viability of small populations subjected to strong effects of demographic stochasticity. Transient and long-term dynamics may account for the commonly observed invasiveness of highly fecund, short-lived species. Given the strong dependence of population viability on population growth and the wide range of transient responses amongst species, transient analysis may provide critical insights into the demographic correlates of biological invasion potential.

Start Date

4-9-2015 10:00 AM

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Apr 9th, 10:00 AM

Transient Dynamics, Life History, and Biological Invasions

The ecological and economic costs of biological invasions create a pressing need to predict species' invasive potential. Traditional invasion analyses focus on factors that influence long-term population dynamics, and thus, the ability for invading populations to persist in novel environments. However, short-term (transient) population dynamics following species introductions may greatly influence population susceptibility to demographic stochasticity. We used published matrix population models to simulate the dynamics of small populations for 84 plant species spanning a range of life histories. From demographic simulations, we estimated the effect of transient and long-term dynamics on invasion success (i.e., population viability) for each species and identify the life history correlates of these dynamics. Transient and long-term population growth rates were positively but independently correlated with population viability across species. The minimum population density attained en route to a stable stage structure was the best transient predictor of population viability, suggesting that avoidance of severe short-term population declines is critical for establishment. Species with high fecundity had disproportionately high transient densities and higher long-term population growth rates. Together, these results suggest that highly fecund species are better equipped to overcome the early effects of demographic stochasticity in the establishment phase than less fecund species and help explain the common empirical finding that species invasiveness is correlated with fecundity. Transient and long-term population dynamics are independent axes of demographic performance that influence the viability of small populations subjected to strong effects of demographic stochasticity. Transient and long-term dynamics may account for the commonly observed invasiveness of highly fecund, short-lived species. Given the strong dependence of population viability on population growth and the wide range of transient responses amongst species, transient analysis may provide critical insights into the demographic correlates of biological invasion potential.