EXPERIMENTAL BASIN STUDIES - AN INTERNATIONAL AND HISTORICAL-PERSPECTIVE OF FOREST IMPACTS

The long tradition of catchment studies in hydrology results from the need to understand the water balance operating in basins, the processe s controlling water movements and the impacts of land-use change on wa ter quantity and quality. The interactions between physical, chemical and biological behaviour have become an increasingly dominant theme in recent years, and this has been boosted by global environmental probl ems such as acid rain and climatic change. After a historical summary of catchment studies, a brief review is given of some of the most infl uential experiments and their underlying objectives and results, conce ntrating on those concerned with one land-use change in particular - t o/from forestry. In interpreting the effects of a change in forest cov er, it is necessary also to consider impacts of the associated site di sturbance, including possible soil compaction and road construction as a result of logging and any artificial drainage before tree planting. The recent tendency to link basin studies into networks is discussed, with examples of currently active networks.