基于Ecopath模型的长江口及毗邻水域生态系统结构和能量流动研究

Study on the Structure and Energy Flow of the Yangtze River Estuary and Adjacent Waters Ecosystem Based on Ecopath Model

根据2000年和2006年秋季长江口及毗邻水域渔业资源和生态环境调查数据,利用Ecopath with Ecosim软件,构建2个时期的长江口及毗邻水域生态能量通道模型,比较分析了三峡工程蓄水前后长江口及毗邻水域生态系统的结构和能量流动特征。模型包含鱼类、虾类、蟹类、头足类、浮游动物、浮游植物、底栖动物、碎屑等17个功能群,基本覆盖了能量流动的途径。分析结果表明,2006年秋季长江口及毗邻水域生态系统的总生物量、系统总流量比2000年秋季有所下降,碎屑链的重要性略有降低;由于低营养级层次渔获物数量的增加,渔获物平均营养级有所下降。2个时期长江口及毗邻水域生态系统的再循环率较低,仍有较高的剩余生产量有待利用,均处于不成熟的发育期。

The study was based on the investigations of fishery resources and environment of the Yangtze River Estuary and adjacent waters in autumn 2000 and autumn 2006. Using the Ecopath with Ecosim software, the mass - balance models of the Yangtze River Estuary and adjacent waters ecosystem were constructed during the two periods. Based on the two models, the changes of the ecosystem structure and energy flow were compared and analyzed before and after the sluice of the Three Gorges Dam. The models included 17 functional groups covering the main trophic flow of the Yangtze River Estuary and adjacent waters ecosystem, which were fishes, shrimps, crabs ,cephalopod, zooplankton, detritus, phytoplankton, benthos, etc. The results indicated that the total biomass and system throughput of Autumn 2006 was lower than that of Autumn 2000, and the role of detritus in nutrient regeneration decreased. The decrease of mean trophic level of catch may be owing to the catch increase of lower trophic level fishes in autumn 2006. Since the Finn cycling index were lower and there were high surplus production, the Yangtze River Estuary and adjacent waters ecosystem in Autumn 2000 and Autumn 2006 were both in developmental stage.