Abstract:

As the most important Ecofunctional districts of the middle reaches of the Yangtze River,Dongting Lake wetland’s ecological functions restrict the sustainable development of economy in this area.With the rapid development of husbandry,the waste from livestock seriously threatens to the ecological environment of regional lake.Judging from the amount of livestock and poultry,environmental threats from excretions of livestock and poultry in Dongting Lake counties(urban)were estimated and analyzed in this study,which included the amount of livestock wastes such as feces and urine,feces equivalent capacity of swine,extent of land to bear the animal manure load.The results showed that various kinds of animal feces and urine excretion of Dongting Lake area were 31727 9 million t in total,equivalent to pig feces equivalent of 29211 3 million t,in 2007.The runoff amount of livestock and poultry manure reached a total of 111048 million t.The amount of COD and ammonia from livestock and poultry excretions were more than 508 000 and 78 100 t.Jugding from livestock and poultry manure load alarm value and the classification outcome,Yueyang Tower district and Miluo City had more serious threats.Ecological environment of Cloud River area,Linli County,Wuling district,Yueyang County,Jinshi City,and Xiangyin County were affected.〖