Climate Change and Invasiveness.

Carbon dioxide is rising in the atmosphere.  Carbon dioxide provides the raw material needed for plants to grow and as it increases, plant growth will be stimulated.  However, the increase in carbon dioxide, and associated changes in temperature are likely to not only stimulate the growth and reproduction of desirable plants, but also to affect the biology of weedy species, particularly invasive weeds.  In this overview I will present data on how CO2 and/or rising temperatures are likely to impact the establishment, growth and reproductive success of three invasive weeds of national importance.  Specifically I will discuss how warming winter temperatures are affecting the northward migration of kudzu, how rising CO2 is affecting cheat grass and fire frequency and how CO2 interacts with nitrogen to affect the growth of Canada thistle.  In addition, I will discuss how CO2 and/or temperature are likely to affect the chemical control of these species.  Although the current data are limited, these existing studies suggest unprecedented, rapid changes in our understanding of invasive weed biology.