基于海洋生态系统管理的EwE建模技术要点

Key Points of EwE Modeling Technology Based on Marine Ecosystem Management

Ecopath with Ecosim (EwE)模型因具有功能完善、使用方便等特点,近年在海洋生态系统管理和研究中得到越来越广泛的应用。基于相关案例,分析并总结了EwE模型应用于海洋生态系统研究与管理的技术要点:Ecopath模型的系统边界在空间上一般应包含系统主要物种的所有生境,在时间上应能体现主要物种的完整生命周期;通常需要将几个具有相似功能的物种合并成一个功能组来简化生态系统;模型参数设置的合理与否需结合生态系统实际加以判断,模型平衡更是需要遵循基本的生态学和热力学规则;使用生态网络方法比较不同模型时需对模型参数进行标准化处理;Ecosim模型对初始参数的变化非常敏感,利用Monte Carlo拟合程序可以有效解决输入参数的不确定性问题;模型建成后建议参照相关标准对模型质量进行定期校验。

Because of its perfect function and convenience compared with other ecosystem models,Ecopath with Ecosim(EwE)is more and more widely used in marine ecosystem management and research in recent years.Based on the analysis of relevant cases,the key technical points of EwE model applied to marine ecosystem management were summarized:The spatial and temporal boundaries of the system must be defined before modeling,which should generally include all habitats of major species in space and the life cycles of common species in time;It is often necessary to combine several species with similar functions into a single functional group to simplify an ecosystem;That whether the setting of model parameters is reasonable is judged according to the actual situation of the ecosystem.Moreover,the equilibrium of the model should follow the basic principles of ecology and thermodynamics;When different models are compared by using ecological network method,parameters should be standardized.As Ecosim model is very sensitive to changes in the initial parameters,Monte Carlo fitting procedure can be used to effectively solve the problem of uncertainty of input parameters.After the model is built,it is recommended that the quality of the model be checked regularly with reference to relevant standards and international common practices.