五里湖生态系统能量流动模型初探

根据2009年五里湖的渔业资源和生态环境调查数据，利用EwE 6.0构建五里湖生态系统的生态通道模型。该模型包括大型鲌、其他食鱼性鱼类、湖鲚、鲤、鲫、野杂鱼、鲢、草食性鱼类、大型虾蟹类、软体动物、其他底栖动物、浮游动物、沉水植物、其他维管束植物、浮游植物和碎屑等17个功能组，基本覆盖了五里湖生态系统能量流动的主要过程。模型分析表明：2009年五里湖生态系统处在趋于成熟时期。生态网络分析表明，生态系统各功能组的营养级范围为1~3.958，能量流动主要有6级，来自初级生产者的能量效率为4.4%，来自碎屑的传递效率为5.1%，平均能量传递效率为4.9%。生态系统功能组直接来源于碎屑的比例占总流量的60%，来源于初级生产者的比例为44%。生态系统的总初级生产计算量/总呼吸量（TPP/TR）、连接指数（CI）、系统聚合度（A）、Finn′s循环指数（FCI）、Finn′s平均能流路径长度(FCL )和系统杂合度（SOI）分别为1.339、0.277、0.267、0.155、3.393、0.119。

The preliminary research of energy flow model on Lake Wuli ecosystem

The study was based on the investigations of fishery resources and environment of Lake Wuli in 2009.Using the Ecopath with Ecosim software beta 6.0,the mass-balance of Lake Wuli ecosystem is constructed to analyze the main biomass flows and trophic flows.The model consists of 17 functional groups,which are Large culters,Other piscivorous,Tapertail anchovy,Common carp,Crucian carp,Bighead carp,Other fishes,Silver carp,Herbivorous fishes,Macrocrustaceans,Molluscs,Other benthos,Zooplanktons,Submerged Macrophytes,Other macrophytes,Phytoplanktons,Detritus.Each group represents organisms with a similar role in the food web,and the functional groups cover the main trophic flow in the ecosystem.Through network analysis,the ecosystem of Lake Wuli reached maturity in 2009.Trophic levels of the compartments vary from 1.00 to 3.958 6.The system net work is mapped into a linear food chain and six discrete trophic levels are found with a mean transfer efficiency of 4.4% from detritus and 5.1% from the primary producers within the ecosystem.The geometric mean of the trophic transfer efficiencies is 4.9%.In the course of energy flow,the proportion of total flow originating from detritus is 56%.and that from the primary producers is 44%.The parameters of this ecosystem: Total primary production/total respiration(TPP/TR),Connectance Index(FC),Ascendancy(A),Finn′s cycling index(FC),Finn′s mean path length(FCL)and System Omnivory Index(SOI) are: 1.339,0.277,0.267,0.155,3.393,0.119 respectively.