Nutrient leaching from leaf litter of emergent macrophyte (Zizania latifolia) and the effects of water temperature on the leaching process

Abstract

To quantify nutrient loading from emergent macrophytes through leaching in the littoral zones of Paldang Reservoir, we conducted incubation experiments using leaf litter of the emergent macrophyte, Zizania latifolia. To separate the leaching process from microbial decay, we used HgCl2 to suppress microbial activity during the experiment. We measured electric conductivity, absorbance at 280 nm, total nitrogen and dissolved inorganic nitrogen, total phosphorus and soluble reactive phosphorus, Na, K, Mg and Ca amounts in leaf litter and in water. In addition, we examined the effects of water temperature and ion concentrations of ambient water on the leaching process. A total of 6% of the initial ash‐ free dry mass of leaf litter was lost due to leaching during incubation (four days). Electric conductivity and A280 continued to increase and saturate during the incubation. To compare reaching rates of different nutrients, we fitted leaching dynamics with a hyperbolic saturation function [Y=A•X/(B+X)]. From the...