Decomposition and Nutrient Dynamics of Aquatic Macrophytes in Lake Paldang

Abstract

This tudy examined the decomposition of blades and culms of aquatic emergent plant species,Zizania latifolia, Phragmites comunis and Typha ngustata , and changes in utrient contents during decom-position. Z. latifolia,P. comunis and T. angustata were the most frequently ocuring species in Lake Paldangof Han River, Korea. Experiments were caried out from July 27 to December 14, 205 in Lake Paldang usingthe liter bag method. The remaining mases of blade liter of each species at he nd of experimental periodwere 21.2% of initial dry weight in Z. latifolia, 32.5% in P. comunis , and 4.7% in T. angustata. In adition, theremaining mas of culm was 2.6% of initial dry mas in Z. latifolia, 56.4% in P. comunis , and 38.1% in T.angustata . During the liter decomposition period, P, K, Na, and Mg concentration decreased rapidly within 10days, but Ca nd Mn concentration declined slowly. K content s remained below 10% of initial values in al itersamples retrieved uring decomposition, whereas Ca nd Mg c oncentration remained above 40% and 50%during decomposition in al thre species. Na, P and Mn conte nts in liter varied among species and plant parts.P concentration in culms ofP. comunis remained at about 60% of initial concentration throughout he study,but he remaining P content in culms of Z. latifoliawas only 10% of the original value at he nd of the studyperiod. The Mn concentration in blades of P. comunis increased about 15-fold relative to the initial contentby the nd of experiment.