Perspectives of Ecological Engineering to Enhance Nutrient Removal in Wetlands

Abstract

I propose management practices which can maintain removal mechanisms of nutrients in wetlands and enhance the transformation of nutrients into valuable biological resources. In brief, characteristic biogeochemical processes of nitrogen and phosphorus under aerobic and anaerobic conditions are considered to effectively treat nutrient-enriched wastes in wetlands. Based upon diverse food chains and biomanipulation, a water quality perspective requires that wetlands be managed to function not only as a sink of nutrients but also as a source of organisms which are dispersed to adjacent terrestrial sinks of organisms. Finally, I also propose some prospective research subjects to test hypotheses related to the management practices. Narrow riparian areas lying along Korean rivers and streams are very unique in terms of concentrated rainfall during a short period in summer and steep topography of surrounding catchment areas. A relatively large portion of the area experiences flooding only from early June to early September, while it is almost dry like terrestrial systems from fall to late spring. Only its small area is comparable to a wetland during the period of dry season, and allows hydrophytes to grow or lie dormant. This situations may make the Korean riverine wetlands less effective in conserving nutrients as well as water within inlands. The unique rainfall pattern and topography are major challenges that Korea faces in managing water resources quantitatively and qualitatively. A better management, especially with the challenge, will be achieved when nutrientenriched water is distributed to many small wetlands in a catchment rather than concentrated to one big reservoir.