• Aquifers Ecology;
  • Floodplains;
  • Gradient analysis;
  • River restoration;
  • Stream regulation;
  • Dams


The general effects of single dams on the downstream ecology of temperature lotic systems are predictable, although some underlying causal mechanisms remain elusive. Few quantitative data of an ecological nature are available for regulated tropical rivers, however, and it would not be prudent to uncritically apply principles and patterns developed from temperate rivers to fluvial systems of the tropics. New techniques of gradient analysis appear especially suited to examining spatial recovery gradients below dams at any latitude and portend to provide considerable insight into the mechanisms responsible for such patterns. Few studies have specifically examined the influence of regulation on interactions between the river channel and the floodplain and virtually nothing is known of channel-aquifer interactions. A fuller understanding of these interactive pathways is necessary to effectively regulate discharge as part of river restoration strategies. Viewing regulated streams as experimental systems for addressing ecological questions has proved to be useful and should be further exploited. It is concluded that research and expertise in regulated stream ecology will increasingly be needed as the rational basis for flow criteria to conserve, protect and enhance the societal values of regulated rivers world-wide.