The Bear Brook Watershed in Maine (BBWM) is a long-term, whole-watershed study examining the effects of experimentally elevated N and S deposition on a treated watershed, in comparison to the adjacent reference watershed. The study is in a northern New England, USA, forested ecosystem, and focuses on soil and stream hydrological and biogeochemical processes, and chemical responses of vegetation. Relative to the reference watershed, the treated ecosystem has migrated biogeochemically towards N saturation, and soil and stream acidification. Some of the responses to N amendments were not expected nor predicted by available models.

various places of the world. Thus, it is hoped that this up-to-date subseries would increase the "awareness" of the world's citizens and encourage governments to devote more attention and resources to address this issue. The series editors thank the international panel of contributors for bringing this timely series into completion. We also wish to acknowledge the very insightful input of the following colleagues: Prof. A. L. Page ofthe University of California, Prof. T. C. Hutchinson of the University of Toronto, and Dr. Steve Lindberg of the Oak Ridge National Laboratory. We also wish to thank the superb effort and cooperation of the volume editors in handling their respective volumes. The constructive criticisms of chapter reviewers also deserve much appreciation. Finally, we wish to convey our appreciation to my secretary, Ms. Brenda Rosier, and my technician, Ms. Claire Carlson, for their very able assistance in various aspects of this series. Aiken, South Carolina Domy C. Adriano Coordinating Editor Preface to Acidic Precipitation, Volume 4 (Advances in Environmental Science) Acidic precipitation and its effects have been the focus ofintense research for over two decades. Initially, research centered on the acidity status and acidification of surface waters and consequent impact on the status of sports fisheries; evidence suggested impacts on fisheries in Sweden and Norway, and in North America, in eastern Ontario, Quebec, and in the Adirondack Mountains of New York.

various places of the world. Thus, it is hoped that this up-to-date subseries would increase the "awareness" of the world's citizens and encourage governments to devote more attention and resources to address this issue. The series editors thank the international panel of contributors for bringing this timely series into completion. We also wish to acknowledge the very insightful input of the following colleagues: Prof. A. L. Page ofthe University of California, Prof. T. C. Hutchinson of the University of Toronto, and Dr. Steve Lindberg of the Oak Ridge National Laboratory. We also wish to thank the superb effort and cooperation of the volume editors in handling their respective volumes. The constructive criticisms of chapter reviewers also deserve much appreciation. Finally, we wish to convey our appreciation to my secretary, Ms. Brenda Rosier, and my technician, Ms. Claire Carlson, for their very able assistance in various aspects of this series. Aiken, South Carolina Domy C. Adriano Coordinating Editor Preface to Acidic Precipitation, Volume 4 (Advances in Environmental Science) Acidic precipitation and its effects have been the focus ofintense research for over two decades. Initially, research centered on the acidity status and acidification of surface waters and consequent impact on the status of sports fisheries; evidence suggested impacts on fisheries in Sweden and Norway, and in North America, in eastern Ontario, Quebec, and in the Adirondack Mountains of New York.

In order to provide meaningful information for evaluating environmental consequences of alternative control strategies of air pollutant emissions, scientists have recently initiated numerous studies aiming at collecting and making use of regional data. New kinds of mathematical models have been developed that no longer are calibrated just for individual stands or catchments but can be applied on a large regional scale. Such regional models and data were reviewed at a meeting" Models to describe the geographic extent and time evolution of acidification and air pollution damage", organized by the Finnjsh Research Project on Acidification (HAPRO), and held in Aulanko, Hiimeenlinna, Finland, July 5-8, 1988. This volume is based on the outcome of that meeting. The chapters of the volume are written by leading scientists in the field. The main objective of this volume is to discuss the potential of regional models to analyze the geographic extent of acidification as well as the environmental damage and the time evolution of:the responses of the environment. First, in Part I of the volume, sensitivity distributions of ecosystems, forest soils and surface waters are described. The focus of interest is therefore extended from the most sensitive ecosystems to sensitive and moderately sensitive parts of the environment. When formulating national and interna tional targets, it is of crucial importance to know the whole distribution of critical loads within the area, and not only the level the most sensitive ecosystem can tolerate.

The Bear Brook Watershed in Maine (BBWM) is a long-term, whole-watershed study examining the effects of experimentally elevated N and S deposition on a treated watershed, in comparison to the adjacent reference watershed. The study is in a northern New England, USA, forested ecosystem, and focuses on soil and stream hydrological and biogeochemical processes, and chemical responses of vegetation. Relative to the reference watershed, the treated ecosystem has migrated biogeochemically towards N saturation, and soil and stream acidification. Some of the responses to N amendments were not expected nor predicted by available models.

This book, from the series Primary Sources: Historical Books of the World (Asia and Far East Collection), represents an important historical artifact on Asian history and culture. Its contents come from the legions of academic literature and research on the subject produced over the last several hundred years. Covered within is a discussion drawn from many areas of study and research on the subject. From analyses of the varied geography that encompasses the Asian continent to significant time periods spanning centuries, the book was made in an effort to preserve the work of previous generations.