Climatic drivers for changes in native and nonnative plant phenology

Background/Question/Methods

Understanding species responses to global change will help predict shifts in species distributions as well as aid in conservation.  Spring events such as leaf unfolding and flowering are associated with changes in air temperature.  Changes in the timing of seasonal activities of organisms over time may be the most responsive and easily observable indicator of environmental changes associated with global climate change.  It is unknown how global climate change will affect species distributions and developmental events in subtropical ecosystems or if climate change will differentially favor nonnative species.

Results/Conclusions

Here I document a trend for delayed seasonal flowering among plants in Florida.  Additionally, there were few differences in reproductive responses by native and nonnative species to climatic changes.  The vast majority of empirical research has documented earlier reproductive onset with increasing spring temperatures, and these studies have largely occurred in mid to higher latitudes. I argue that plants in Florida have different reproductive cues than those from more northern climates.  With global change, minimum temperatures have become more variable within the temperate-subtropical zone that occurs across the peninsula and this variation is strongly associated with delayed flowering among Florida plants.  Research on climate change impacts need to be extended outside of the heavily studied higher latitudes to include subtropical and tropical systems in order to properly understand the complexity of regional and seasonal differences of climate change on species responses.