The biosphere is the ultimate sink for air pollutants and is also the source of many precursors for the formation of photo-oxidants. In any analysis of air pollution and for determining source-receptor relationships, reliable emission and pollutant concentrations or depositions must be taken into account, together with their interactions between the atmosphere and the biosphere. This book presents a number of authoritative review articles covering topics which include biosphere-atmosphere exchange of ammonia, nitrogen oxides, ozone and sulfur-containing gases, the biological mechanisms involved in the exchange of trace gases, as well as generalizations of deposition over Europe.

This volume contains the invited papers and a transcript of the final panel discussion in the First Scientific Conference of the International Global Atmospheric Chemistry (lGAC) Project, held in Eilat, Israel from April 18-22, 1993. The conference was hosted by the Israeli Institute for Biological Research (IIBR) and was the 37th in the prestigious OHOLO Conference series in Israel. The conference was devoted to the subject of "Global Atmospheric-Biospheric Chemistry" and was a landmark event in this area. It provided the first comprehensive report of progress under IGAC toward improving our understanding of the chemical and biological processes that determine the changing composition of the earth's atmosphere. This work is an essential component of the comprehensive International Geosphere Biosphere Program (lGBP) devoted to measuring and understanding global changes in the past and present, and predicting the future evolution of our planet. I want to devote this brief foreword to thanking several people who worked especially hard to make the conference a success and who helped to produce this volume as a record of the event. Paul Crutzen, Amram Golombek, Pamela Matson and Henning Rodhe did sterling service on the conference organizing committee. Special thanks go to Amram Golombek and Dr. Cohen, the Director of IIBR, who hosted the event in Israel. Anne Slinn did an excellent job in producing the Abstract book and helping with administrative matters. Alex Pszenny helped capably to critically review the Abstracts.

This comprehensive volume is the first to consider biomass burning as a global phenomenon and to assess its impact on the atmosphere, on climate, and on the biosphere itself.

Atmospheric abudance of trace gases since the pre-industrial time has forced the earth's climate to change, threatening food security. Exchange of biogenic trace gases between the atmosphere and the biosphere is directly or indirectly influenced by the plants. This volume contains the latest findings on the correlation between the climate change and biogenic gas emission, plant response to elevated levels of carbon dioxide, temperature, ozone and UV-B in combination and alone, regulatory mechanism of methane, nitrous oxide and ammonia emission and their mitigating options. Ecologists, atmospheric scientists, plant physiologists, research scholars, teachers and post-graduate students will benefit from this book.

The material presented here is based on presentations and discussions held at the 1990 Sigtuna workshop. We have organized the material into five sections, the first containing papers of general relevance to all the developed research plans, followed by three sections divided by geographical regions (high-latitude, mid-latitude, and tropical ecosystem regions), and the final section dealing with rice paddy agriculture, which because of its potential role as a significant source of CH4 and N2O was singled out for a specific set of studies. Each section, except the first dealing with general issues, concludes with a working group report developed at the workshop. These reports identify specific research needs to address biosphere atmosphere exchange research for each region.