Impact of air pollution on terrestrial ecosystems

Abstract

This chapter summarizes the current state of knowledge on the impacts of air pollution on terrestrial vegetation in general and in the Mediterranean region. These impacts occur either indirectly through changes in the physical state of the atmosphere, such as increase in the temperature (caused by greenhouse gases), and in the diffuse radiation (caused by aerosols) that reaches vegetation, or directly through phytotoxicity resulting from ozone, sulfur, nitrogen, and other pollutants' stomatal and non-stomatal uptake by the plants, nutrient balance modification by atmospheric deposition, transfer of plant diseases by aerosols, and pollution by persistent pollutants and metals. Abiotic and biotic stresses can also alter the composition, amounts, and functioning of volatile organic compounds that are emitted by the plants and play known ecological roles. These impacts are summarized, and plant physiological responses to an excess of critical nutrient levels are presented and discussed.