%0 Journal Article
%T Relationship between Vegetation Composition and Dissolved Nitrogen in Wetlands of Higashi-Hiroshima, West Japan
%A Haidary Miandoab
%A Azam
%A Kaneyuki Nakane
%J Journal of Ecology and Field Biology
%D 2007
%I 
%X Twenty-four wetlands located in Higashi-Hiroshima City in West Japan were selected for this studyin order to investigate both the relationship between aquatic plant composition and environmental conditions; andthe relationship between changing land use patterns in the catchments and the concentration of different formsof nitrogen in the wetlands. The dominant and subdominant species which comprised the principal vegetationwere determined based on a vegetation census conducted in each wetland during the growing season from Juneto August, 2006. The seasonal variations of water quality factors (pH, electrical conductivity, turbidity, dissolvedoxygen, total dissolved solid, and temperature) and different forms of nitrogen such as nitrite, nitrate, ammonium,total nitrogen, dissolved organic nitrogen and dissolved inorganic nitrogen concentrations were analyzed asimportant indicators of water quality for the surface water of the wetlands. The surveyed wetlands were classifiedinto three types (non-disturbed wetlands, moderately-disturbed wetlands and highly-disturbed wetlands), basedon the degree of human disturbance to their catchment areas. An analysis of variance indicated that there wasa significant difference among the wetland groups in the annual mean values of electrical conductivity, totaldissolved solids, total nitrogen, nitrite, dissolved inorganic nitrogen and dissolved organic nitrogen. Classificationof the wetlands into three groups has revealed a pattern of changes in the composition of plant species in thewetlands and a pattern of changes in nitrogen concentrations. A majority of the non-disturbed wetlands werecharacterized by Brasenia schrebi and Trapa bispinosa as dominant; with Potamogeton fryeri and Iris pesudacorusas sub-dominant species. For most of the moderately-disturbed wetlands, Brasenia schrebi wereshown to be a dominant species; Elocheriss kuriguwai and Phragmites australis were observed as sub-dominantspecies. For a majority of the highly-disturbed wetlands, Typha latifolia and T. angustifolia were observed asdominant species, and Nymphea tetragona as the sub-dominant species in the study area. An analysis of landuse and water quality factors indicated that forest area played a considerable role in reducing the concentrationof nutrients, and can act as a sink for surface/subsurface nutrient inputs flowing into wetland water, anchor thesoil, and lower erosion rates into wetlands.
%K Dissolved nitrogen
%K Vegetation
%K Water quality
%K Wetland
%U http://ocean.kisti.re.kr/is/mv/showPDF_ocean.jsp?method=download&pYear=2007&koi=KISTI1.1003%2FJNL.JAKO200735836630122&sp=209&CN1=JAKO200735836630122&poid=kesk&kojic=STHHCL&sVnc=v30n3&sFree=