Are nonnative species better at tracking climate change than natives?

Background/Question/Methods

Climate change varies around the world and concomitant ecological responses are likely to differ by region. Understanding species responses to global change will help predict shifts in species distributions as well as aid in conservation planning and management.  It is expected that most aspects of global climate change will favor nonindigenous species because invasive species share traits that allow them to capitalize on these perturbations. In fact, warming temperatures have allowed nonnative species to expand their ranges into areas where they previously could not survive and reproduce. However, the capability of nonnative species track climate change better than native species remains an open question. We used statistical models to evaluate the environmental drivers that affect changes in plant reproductive timing of high impact nonnative species and closely related native plant species in Florida. This was done by correlating the timing of flowering of individual herbarium specimens with the local climatic conditions at the time of, or prior to, flowering. With this research, we test the hypothesis that nonnative species will track changing climatic conditions better than closely related native species.

Results/Conclusions

Only seven out of 54 comparisons (13%) of flowering responses resulted in in a significant difference between closely related native and nonnative species. This suggests that in Florida, where the environment is changing by becoming more variable over time, most native and nonnative species do not differ in their response to climate change. However, in five of these seven significant differences, the nonnative species demonstrated a significant response to the variable of interest and the native species had a neutral response to the changing environmental condition. This suggests that in these cases, the nonnative species are more responsive to changing environmental conditions than native species. Whether these responses are due to phenotypic plasticity or rapid adapationa remains an open question. Other empirical studies have demonstrated that nonnative species have variable responses to altered temperatures and precipitation levels, relative to native species which suggests that the nonnative species that will be favored will depend on the nature of the changing climate in a particular region.