Climate change presents challenges for many plant and animal species that influence their extinction risk. As global temperature increases, suitable habitats shift poleward and require local populations to track suitable habitat, adapt, or die. The spatial and temporal dynamics of plant populations make understanding and predicting their responses to global change particularly challenging. There are over 390,000 plant species globally. Of these, only about eight percent have been assessed for their conservation status. In addition, many of the species-specific data that exist are incomplete. To predict movement-related extinction risk for plants worldwide, we synthesize available data on dispersal, demography, and functional traits to create a Bayesian multivariate model representing trade-offs among life history traits. We then use this model to generate virtual species representing realistic demography and dispersal scenarios. Finally, we use each virtual species to parameterize mechanistic models for spatial population dynamics -- integrodifference equations -- and perform mathematical analysis to estimate spread rates.
Results/Conclusions
We built the statistical model and initially generated 15,000 virtual species. For this preliminary analysis, approximately one-third of these had declining population growth rates (lambda < 1). As integrodifference equations assume growing populations (lambda > 1), we parameterized the integrodifference equation using virtual species with population growth rates greater than one. Results of the mathematical analysis show a majority of spread rates falling below the estimated speed of climate change-driven habitat movement (0.42 kilometers per year). Spread rates are positively correlated with leaf area, leaf nitrogen, and wood density. This link between functional traits and spread rates demonstrates how this approach can inform types of species least likely to track a shifting climate. This will help identify species at greatest risk and aid the development of conservation strategies to ensure their persistence under climate change.