基于Ecopath模型的千岛湖生态系统结构和功能分析

ANALYSIS ON THE ECOSYSTEM STRUCTURE AND FUNCTION OF LAKE QIANDAO BASED ON ECOPATH MODEL

  • 摘要: 为探索千岛湖生态系统现状及其历史变化, 根据2016年千岛湖的渔业资源与生态环境调查数据, 构建了千岛湖生态系统的 Ecopath 模型, 综合分析系统的能量流动过程、营养级结构和生态系统总体特征。2016年千岛湖 Ecopath 模型由18个功能组组成, 有效营养级范围为1—3.41, 牧食食物链的能量流动占系统总能量的56%。系统杂食指数(SOI)、联结指数(CI)、Finn循环指数分别为0.13, 0.26和5.15%。千岛湖与其他湖泊和水库比较, 其生态系统的各功能组的聚合度较高, 联结程度较为紧密, 物质再循环比例较高, 系统较为成熟。但千岛湖的系统总流量较低为24698.27 t/(km2·a), 总初级生产量与总呼吸量的比值为6.51, 表明系统总体规模较小且仍处于发展阶段。根据千岛湖生态系统历年变化趋势分析: 千岛湖生态系统的总体规模有变大趋势, 稳定性和复杂性有所增强, 但营养交互关系变弱, 系统抵抗外界干扰的能力仍较低。同时, 千岛湖生态系统的初级生产者转化效率较低, 食物网趋于简单, 应采取适当的管理措施, 以保障千岛湖生态系统的健康发展。

     

    Abstract: To explore the current status and historical change of the Lake Qiandao ecosystem, the Ecopath model of the Lake Qiandao ecosystem was constructed based on the survey data of fishery resources and water environment in Lake Qiandao in 2016. And the trophic level structure, energy flow and ecosystem characteristics were analyzed based on this model. The Ecopath pedigree index (P index) was 0.54, with high data reliability. Ecopath model was consisted of 18 functional groups, and the fractional trophic levels ranged from 1 to 3.14. Energy flow of Lake Qiandao ecosystem was dominated by grazing food chain, which accounted for 56% of the energy source. Parameters reflected the complexity of the ecosystem, For example, the system connectance index (CI), the omnivory index (SOI), the Finn cycling index and the Finn mean path length were 0.26, 0.13, 5.15% and 2.46, respectively. Compared with other reservoirs, it showed that the functional groups of Lake Qiandao ecosystem had a higher polymerization, a closer connection, a higher rate of material recycling and the ecosystem was more mature. However, the total system throughput of Lake Qiandao in 2016 was low with 24698.27 t/(km2·a), and the total primary production was 6.51 folds of the total respiration, which indicate that the scale of Lake Qiandao ecosystem was small and still in a developmental stage. According to the historical analyses of the Lake Qiandao ecosystem, the scale of this ecosystem has become larger, and the stability and complexity have been enhanced, but the nutrient interaction relationship was weakened, and the ability of the ecosystem to resist external interference was still weak. At the same time, the conversion efficiency of primary producers of Lake Qiandao ecosystem was low, and the food web was simple. So appropriate management measures should be taken to ensure healthy development of Lake Qiandao ecosystem.

     

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