Acid precipitation monitoring and research. Review of current Norwegian activities

Abstract

Acid precipitation is a major threat to Norwegian ecosystems. Damage to aquatic biota has occurred in large areas of southern Norway, deterioration of vegetation and forest is expected to develop, and human health may be affected. Apart from the short-term economical losses, the negative development of environmental quality is giving rise to public concern. Politically and administratively, the issue has been given top priority among environmental issues for nearly 20 years. Hence, fairly large resources are spent on monitoring and research activities, reduction measures and local ameliorating countermeasures. During the seventies, a joint, interdisciplinary research and monitoring project was carried out to establish basic knowledge of the cause/effect relationships and the extent of the problems caused by acid precipitation. From 1980 onwards the activities were continued within a separate monitoring programme and within different research projects which comprised part of the general scientific activity. The monitoring program is administratively and thematically divided into four major categories emphasizing air processes, water, aquatic fauna, and forest and vegetation. The main purpose of the programme is to reveal the temporal trends and to assess the geographical distribution of effects. The deposition of most pollutants, except NO x , peaked during the late seventies, though the levels are still at the same order of magnitude. The acidification of soil and waters, in terms of loss of acid neutralizing capacity, has tended to increase during the last decade, at least in the impacted areas of southernmost Scandinavia. The damage to aquatic fauna is still increasing, wiping out additional numbers of fish stocks every year. Severe impact on forest and vegetation is feared and the data from 1987 indicate that damage already occurs in some areas. Research projects are carried out on nearly every aspect relevant to acid precipitation. Priority has been given to research areas with the most severe effects and where considerable lack of knowledge is evident. Present high priority areas are: photo-oxidants and nitrogen compounds, transformation processes and effects; mechanisms, dose/response relationships for acidification/ recovery of soil and waters; effects on forest and vegetation; effects of aluminium; and restoration of fish stocks. Norwegian scientists cooperate extensively with groups in other countries and participate in international monitoring networks and research programmes.