近自然湿地生态修复的概念、理论与实践

Concept,theory and practice of near-natural wetland ecological restoration

随着对湿地重要性认知的提高,我国对湿地生态修复技术的需求也日益增加,其中近自然湿地生态修复备受关注。描述了近自然概念的由来,提出了近自然湿地的定义并辨析了其与人工湿地的主要区别。以太湖竺山湖湿地生态修复为例,介绍了近自然湿地生态修复的设计思路、主要技术措施和修复效果。在竺山湖近自然湿地生态修复中,依次实施了水文水动力改善、基底形态营造、植物恢复、水生动物恢复、生物量管理等措施,具体包括:改善水体连通性和流动性,提高生境多样性和适宜性;基于5种基底形态对污染物去除效果的分析,构建了多起伏型基底形态;根据土著适生、净化水质、兼顾景观等原则,筛选出21属35种土著湿地植物,设计并应用了2种植物配置模式;根据生态系统调控(EwE)模型对湿地食物网结构的分析结果,对水生植物收割量、鱼类及虾蟹类的种群数量提出了调控建议。生态修复后竺山湖水质由劣Ⅴ类改善为Ⅱ类(GB 3838—2002《地表水环境质量标准》),大型水生植物多样性显著提高。竺山湖湿地生态修复效果验证了近自然生态修复方法的有效性,今后还需不断在实践应用过程中丰富近自然湿地生态修复的理论及技术,并开展大规模的实践应用。

With the increasing recognition of the importance of wetlands,the demand for wetland ecological restoration techniques is increasing in China,among which near-natural wetland restoration method has attracted more and more attention.The history of the development of near-natural method was reviewed.The definition of near-natural wetland was put forward,and the main differences between near-natural wetland and constructed wetland were analyzed.The ecological restoration of Zhushanhu wetland in Taihu Lake was used as an example to illustrate the design process,main technical measures and restoration effects of near-natural ecological restoration.In the near-natural ecological restoration of Zhushanhu wetland,measures such as the improvement of hydrological and hydrodynamic conditions,the construction of basement forms,plant restoration,aquatic animal restoration,and biomass and species management were successively implemented.The connectivity and mobility of water bodies were improved,the habitat diversity and suitability were enhanced.The wave style basal morphology was constructed based on five types of basement morphology.According to the principles of suitable habitat,priority of water purification and consideration of landscape,35 species of indigenous wetland plants from 21 genera were selected,and two plant configuration models were designed and used in Zhushanhu wetland restoration process.Based on the analysis results of Ecopath with Ecosim(EwE)model on the structure of wetland food web,some suggestions were put forward on regulating the harvest of aquatic plants and the population number of shrimps,crabs and fishes.After ecological restoration,the water quality of Zhushanhu wetland was improved from below ClassⅤto ClassⅡof Environmental Quality Standards for Surface Water(GB 3838-2002),and the diversity of large aquatic plants increased significantly.The ecological restoration effect of Zhushanhu wetland has proved the effectiveness of near-natural ecological restoration methods.In the future,it is necessary to continuously enrich the theory and technology of near-natural ecological restoration in practice and carry out large-scale practical applications.