ISSN:
1573-2932
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract During the last three decades the experimental manipulations of whole ecosystems have been shown to be a useful and widely used tool for investigation of the effects of air pollution, air pollution reduction strategies and management practices on the health and productivity of forests and the acidification of catchments and fresh waters. Generally the aims have been to investigate the impact of a continued or increased load of air pollutants on the ecosystems, and the possibilities of reversing the acidifying effects by soil amelioration, addition of buffer acting substances or by removal of the air pollutants. Along with the field experiments, models have been developed to predict future effects and dynamics in the ecosystems under different air pollution scenarios. The present paper gives an overview of experimental field manipulation studies and examples of results obtained with the acidification model MAGIC. All the acidification recovery studies performed so far have shown that a reduced input of S to the ecosystem immediately from the first year resulted in reduced output, although the expected parallel reduction in output of Al and H+ did not occur until some years later, or not at all. The MAGIC model generally predicts the results of both acidification and liming field experiments very well, apart from minor discrepancies in year-to-year variability around the observed trends. Several experimental studies have confirmed that reduced input of acidity or increased input of base cations caused no or only slight changes in the pH in the soil. The buffer processes of the soil may cause the effects to be restricted to the very top soil layer, unless the manipulations were very strong. It is concluded that experimental field studies have increased our understanding of the complexity of the ecosystem and highlighted the need for studies integrating field and laboratory work.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00483690
