Distribution Of Carbon, Nitrogen, Phosphorus And Affected By Droppings’ Decompositon In The Rongcheng SWAN Lake

The Rongcheng Swan Lake in Shandong province is an important coastal wetland and famous whooper swans’habitat in the world. It is of great significance for protecting swans and studying the ecological cycle in the Swan Lake. Nowadays,the ecotope in Swan Lake is turning to be better,and the amounts of swan are becoming more and more,which is a pressure on ecological environment.This study analyzed the distribution of C,N,P in water and sediment and the decomposition process of droppings,and discussed its influence on the quality of water and ecological environment in the Swan Lake.This research would provide some help for the protection of swan and ecological restoration in the Swan Lake.The following conclusions were shown below:(1)Some obvious seasonal changes were observed in the TN and TP of water in the Swan Lake.TN varied from 687.49ng/ml to 1595.79ng/ml in the summer and from 117.99ng/ml to 563.20ng/ml in the winter.TP was between 31.55ng/ml and 144.08ng/ml in the summer and between 7.52ng/ml and 64.80ng/ml in the winter.This meaned the Rongcheng Swan Lake was in a state of excessive nitrogen eutrophication.(2)The TOC of sediment in the Swan Lake was between 0.674%-3.135% in the summer and 0.463%-1.816% in the winter.TN was between 0.109%-0.253% in the summer and 0.064%-0.159% in the winter.TP was between 0.024%-0.067% in the summer and 0.014%-0.048% in the winter.From the coast into the lake,TOC,TN and TP increased,and the correlations of TOC,TN and TP were good.(3)The droppings of swan released a quarter of nutrient in four days when decomposing in winter.With the amount of swans increasing, the droppings would become a significant source of eutrophication.