Impacts of Air Pollutants on Crops, Trees and Ecosystems

Abstract

This chapter provides an overview of the effects of major air pollutants on crop yields, forest health and ecosystem services, drawing primarily on examples from studies in Europe, but also in North America and Asia. It highlights key mechanisms underlying these effects of air pollution, and the interactions between effects of air pollutants and other environmental stresses. For all the air pollutants considered, we have a good understanding of the mechanisms and effects on individual plants, but the cascade of effects, and the interactions with other biotic and abiotic factors, which lead to effects at an ecosystem and landscape scale are much less certain. There is clear evidence that current levels of air pollution across Europe can reduce the food, fuel and fibre provided by ecosystems, modify the way that ecosystems contribute to regulation of water, climate and pollination, and degrade the cultural services they provide, although, in some cases, enhancement of these ecosystem services can also occur. The greatest effects of air pollution over this century, however, are likely to be in regions of the world where we know very little about the response to air pollution of the local crops and plant communities.