Air pollution and global change impacts on forest ecosystems: Monitoring and research needs

The start of the 21st century brings an increasing public awareness of environmental issues worldwide. In this book, we have attempted to present the current state of knowledge about CO2 effects and related global warming on forest productivity and ecosystem function and to discuss research needs in that regard. In addition, we have discussed other air pollutants including O3, nitrogen and sulfur compounds, and heavy metals. The status of those pollutants globally and some representative effects on forest trees and forest ecosystems have been presented. Certainly, there remains much to do in monitoring air pollutants, particularly in rural and forested areas. For example, very little is known about expanding pollutant loading in forest areas of developed countries or across both urban and forest areas in developing countries where the need to industrialize is generally outweighing the resources to control pollutant emissions. While great strides have been made in the past few decades to decrease acidic deposition in North America and Europe, there remain extensive areas of the world\u27s forests being impacted by acidic deposition. Similarly, large areas (25%) of the world\u27s forests are currently exposed to elevated levels of O3 and this is projected to rise to fully 50% of the world\u27s forests by the year 2100. Thus, research is needed to document pollutant effects and to reduce uncertainties about forest productivity and forest ecosystem responses worldwide in the next century. In this chapter, we summarize the eight major research and monitoring needs for the investigation into air pollutant impacts on forests worldwide. © 2003 Elsevier Science Ltd. All rights reserved