Conclusions and Recommendations
Although there were a great diversity of views expressed on many topics at the conference, there was nevertheless a good deal of consensus on some fundamental aspects of the symposium topic. It was emphasised that there is little solid evidence to date of the occurrence of visible or even detectable damage to terrestrial ecosystems caused by the acid precipitation events of the past twenty years. This provides a marked contrast with that of lake ecosystems where substantial effects have been recorded. The reasons for this lack of damage to date are believed to be of several kinds. One is that naturally acidic soils are very widespread, especially in those areas experiencing lake acidification. Forest growth and the essential soil processes are thus able to function at low pH (3.5–4.5). A second factor is that most soils have a relatively high buffering capacity which is contributed by their base status, by carbonates, organic content and by the clay minerals. Agricultural soils are traditionally limed, as required, to maintain pH in a desirable range for plant growth. The delegates were in agreement that although cation loss may be accelerated by acid rains, fertiliser and lime additions would far outweigh deleterious impacts of H+ ion additions.
KeywordsCombustion Clay Nickel Toxicity Phosphorus
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