湿地植物生态数值模拟进展及鄱阳湖湿地研究示例

Research progress of numerical simulation of wetland plant ecology and research example of Poyang Lake wetland

湿地植物群落结构和空间分布格局对湿地生态系统结构和功能起着决定性作用。传统的野外监测和受控实验在研究大尺度湿地植物群落结构和空间分布方面存在局限,在建立“生态过程-空间格局”有机联系并预测动态变化方面存在不足。因此,数学模型成为研究湿地植物种群扩张、空间分布及相互关系的重要工具。通过综述国内外相关研究文献,按照模型对生态机理及空间格局刻画的程度,湿地植物生态模拟的数学模型可分为统计模型、物种分布模型和种群动力学模型三种类型。尽管当前湿地植物模型在理论方法层面取得一定进展,但环境条件模块与植物模块的时空匹配问题,以及湿地植物生活史过程的机理融合问题显著制约了模型的合理性和准确性。最后,以大型通江湖泊湿地-鄱阳湖为例,构建了水动力驱动下的湿地植物生态数值模拟框架,从机理和应用两个层面提出了湿地植物生态数值模拟的发展方向。在机理层面,应基于通江湖泊独特的水文过程,强化生态学机理支撑;在应用层面,应聚焦江湖关系变化下的水文情势,在水动力模型基础上耦合种群动力学方法,刻画植被演替动态及空间格局,并通过野外调查和遥感影响比对验证,以提高模型精度。

The structure and spatial distribution pattern of wetland plant communities play a decisive role in the structure and function of wetland ecosystems.Traditional field monitoring and controlled experiments have limitations in studying the large-scale structure and spatial distribution of wetland plant communities,and there are deficiencies in establishing the organic link between“ecological process-spatial pattern”and predicting dynamic changes.Therefore,mathematical models have become an important tool for studying the expansion,spatial distribution and interrelationships of wetland plant populations.By reviewing the relevant research literature at home and abroad and according to the degree of model description of ecological mechanisms and spatial patterns,wetland plant simulation can be divided into three types:statistical models,species distribution models and population dynamics models.Although the current wetland plant models have made some progress in the theoretical and methodological aspects,the spatiotemporal matching problem between the environmental condition module and the plant module,and the mechanism integration problem of the life history process of wetland plants significantly restrict the rationality and accuracy of the models.Finally,taking the Poyang Lake,a large-scale lake wetland connected to a river as an example,a wetland plant simulation framework driven by hydrodynamics was constructed,and the development direction of wetland plant simulation was proposed from two aspects of mechanism and application.On the mechanism level,the ecological mechanism support should be strengthened based on the unique hydrological process of the river-connected lake.On the application level,the focus should be on the hydrological situation under the change of the river-lake relationship,coupling the population dynamics method on the basis of the hydrodynamic model,depicting the vegetation succession dynamics and spatial pattern,and carrying out comparison verification by field investigation and remote sensing impact comparison,to improve the model accuracy.