Abstract |
Scientific investigations over the last two decades have examined the processes and effects of acidic deposition on surface waters and their catchments. These studies have been performed on various scales: laboratory benchtop, mesocosm/plot studies, whole system manipulations, and regional and national surveys. The processes and mechanisms of acidification of fresh waters have been studied intensively, and investigations have examined closely associated phenomena that influence the availability, transport, and biogeochemistry of acids and related substances. The authors have learned a great deal about the linkages among watershed processes, hydrology, microbial activities, and water chemistry. These factors interact to create the physical and chemical environment in which biota are exposed to an almost infinite array of conditions. Some of these conditions are so adverse that specific organisms can no longer survive; other conditions may result in sublethal effects that have less visible but important results. The purpose of this group report is to relate what the authors have learned about acification and the fate, transport, and effects of other contaminants that may co-occur with acidic ecosystems. (Copyright (c) 1994 John Wiley and Sons Ltd.) |