Grazers and Browsers in a Changing World: Conclusions

Abstract

The world on which we live is constantly changing, slowly through geological and evolutionary change and rapidly as the result of rainfall events or droughts, storms, hurricanes and cyclones, cold snaps or heat waves, and diurnal changes in light levels. Some of these changes have only local effects but others have global effects. In recent times the world has undergone a dramatic global change in form of the levels of CO2 in the atmosphere, much of it derived from anthropogenic sources (King 2005). Currently, the level of CO2, 380 ppm, has not been experienced by the biota on the planet for over 650,000 years (Siegenthaler et al. 2005). This increased CO2 level is leading to changes in climate with consequences for rainfall and temperature patterns across the globe (IPCC 2001) with knock-on effects for vegetation community composition, and plant chemistry.