Implications of Papyrus (Cyperus papyrus L.)Biomass Harvesting on Nutrient Regulation in Nyando Floodplain Wetland, Lake Victoria, Kenya

Abstract

Harvesting of papyrus biomass plays a significant role in regulating ecosys-tem services of which one of them is nutrient uptake and cycling. Despite Lake Victoria’s wetlands being important, little is understood about its role in nutrient uptake and removal. Although there have been studies done in these wetlands, there is inadequate understanding on the implication of unselective biomass harvesting on the water quality of Lake Vitoria. At the same time, these wetlands are threatened by livelihood-related pressures which are dri-ven by extreme hydrological regimes. This study focused on Nyando flood-plain wetland located in the Eastern part of theshores of Lake Victoria which is a lifeline to many rural communities living around the lake. Papyrus bio-mass harvesting was assessed in two study sites of Nyando wetland and at different seasons in order to determine its implication on nutrient regulating services. Participatory tools, field survey, observation, field measurements and laboratory analysis were used. Harvesting of papyrus removed 530.6 Kg N/g DM/ha/day and 97 Kg P/g DM/ha/day in Ogenya while 771.2 Kg N/g DM/ha/day and 109.2 Kg P/g DM/ha/day wereremoved in Wasare. However, addition of nutrients to the wetland may lead to the problem of eutrophica-tion especially at the site where interaction of wetland and lake water occurs. Understanding the role of papyrus harvesting patterns is crucial forbetter planning and management of this complex resource in a changing environ-ment.