Influence of Atmospheric and Climate Change on Tree Defence Chemicals

Dordrecht

2014

Artikel aus einer ZeitschriftUnselbständiges Werk

14704

200191914

Environmental factors associated with atmospheric and climate change can potentially modify the structure and function of the world s forests. An important indirect effect of environmental variables such as elevated carbon dioxide (CO2), air temperature, ozone (O3), UV radiation, and water-related stress on forests results from the response of tree secondary metabolism. In particular, the concentrations of defence chemicals displayed by trees can change in response to certain climate change factors, and this may influence interactions with herbivores and pathogens, and the broader forest community. An evaluation of the literature relating to climate change effects on tree defence chemicals shows variable results in both direction and magnitude of concentration changes and a dearth of studies on chemicals other than carbon-based phenolics and terpenes. Nevertheless, some generalities are evident. Elevated CO2, O3, and UV-B tend to increase tree phenolics, while mono- and sesquiterpenes remain unchanged. Elevated temperature increases volatile terpene emissions and often foliar terpene concentrations, whereas phenolics are largely unaffected. Water stress tends to increase phenolic concentrations and mild stress can also increase terpene emissions, but the effect of excess water availability remains largely unknown