A detailed analysis of acidification effects on forest soil, rhizosphere and plant life and on the processes connecting them such as nutrient uptake and mineral cycling. Presents findings from the Solling project, an important long-term study on acid rain results in Germany's Black Forest, as well as other European forests which have experienced severe acid rain damage as a means of evaluating and predicting similar harm to U.S. forests.

Concern about acid deposition, commonly referred to as acid rain, as a widespread pollution problem with severe ecological consequences has heightened public awareness. Many authorities fear that acid deposition may be the worst environmental crisis of our industrialized society because of both the global implications and possible widespread, irreversible damage to lakes, soils, and forested ecosystems. Neither state nor international boundaries are exempt from the transport and deposition of airborne pollutants resulting from local and distant emission sources. The dilemma and debate will continue as long as society requires fossil fuels for its energy needs without regard to emission constraints. This book started as a modest attempt to provide a status report on atmospheric transport, the chemical processes which produce acidifying agents, and resultant ecological and economic consequences. The materials in this book have been substantially revised from those presented at the conference in 1983. It became obvious that additional chapters were required when sudden and profound changes occurring in European forests were reported. It is felt that perhaps such damages could be an early warning to forested ecosystems in the northeastern United States and Canada as well as other places throughout the world. Most importantly, it is essential that gained scientific knowledge be translated into required legislation - a section on Policy Issues was incorporated to address these concerns. It is hoped that the reader will become informed and concerned enough to be involved in ll this IIglobal debate. Donald D. Adams Halter P.

The objective of this book is to outline the serious dangers to the soil and forest as a result of continuing emissions of acid-producing gases, thus pointing to the urgent need of their reduction. This volume reviews relevant information dealing with changes due to acidification of the soil and with the physiological processes of the tree involved in nutrient uptake, transfer, and utilization as well as with the nature and degree of damage that has occurred. Written in a comprehensive format, it discusses the importance of viable forests, the vital role of nutrients in the structure and physiology of the tree, and the relevance of prior dieback episodes. This is a valuable resource for those interested in forestry, environmental science, and the pulp and paper industry.

The book begins with an overview of the research topics which were addressed in the three different phases of the Dutch Priority Program on Acidification (DPPA), executed between 1985 and 1994. This chapter is followed by a chapter which deals with the emissions of acidifying substances, the concentrations and the deposition to forest and nature conservation areas. Prognoses are given for the acid deposition in 2000 and 2010; the deposition in the countries surrounding the Netherlands is also mentioned. The differences in the results of the DPPA-II are analysed. The third chapter deals with the effects of exposure and load on forests. The chapter moves from small-scale to large-scale: first the effects in laboratory-scale studies are described, then the effects in the field, both at stand level and on a regional scale. In addition, the critical thresholds (critical level of concentration and critical load of deposition) are discussed. The fourth chapter covers terrestrial ecosystems (or parts thereof) as well as weakly buffered surface waters, springs and other streams. Critical levels and loads are also discussed. The most important results are given in chapter 5. In the appendices of the book, so-called umbrella theme reports on deposition, stand modelling and effects on forests are presented which describe in more detail the scientific work performed in the third phase of the DPPA. This book will be of interest to anyone involved in research related to acidification and eutrophication; i.e., not only those who perform the research in the causal chain from emissions to effects, but also policy-makers and students.