湿地土壤及其环境功能评价体系

湿地土壤是湿地生态系统的一个重要的组成部分,是湿地获取化学物质的最初场所及生物地球化学循环的中介。湿地土壤具有维持生物多样性、分配和调节地表水分、分解固定和降解污染物、保存历史文化遗迹等功能。结合湿地土壤的生态功能、物质“源汇”功能、“养分库”功能、“净化器”功能以及“记忆”功能,利用层次分析法,建立了湿地土壤环境功能评价指标体系及其评价方法,构建了湿地土壤环境功能评价的概念模型。通过对湿地土壤及其环境功能评价研究,有利于进一步明确湿地土壤定义及湿地土壤在湿地中的重要地位,同时也丰富完善了湿地科学的理论体系。

Wetland Soil and Its System of Environment Function Assessment

As the kidney of the earth,wetlands have many functions which include reducing flood levels,moderating global climate condition,controlling runoff in urban areas,buffering shorelines erosion,providing refuge for wildlife and so on.Because of the inning,over-grazing,irrigation,silt sediment,and wetland environment pollution,the wetland area is declining,the fragmentation of wetland landscape is more obvious,the loss of the biodiversity is severe,so it is high time that we took measures to protect wetlands.Wetland soil is one of the important components of the wetland ecosystem,which is the initial place to get chemical substances and the medium of biogeochemical cycle.A lot of wetland definitions have been given by wetland scientists,so it is a problem to definite the wetland soil.Based on basic elements of wetland and its hydrological and biological characters,wetland soil was defined as follows: wetland soil is a soil that is flooded,ponded long term or ponded during the growing season to favor tie growth and regeneration of hydrophytic vegetation.This definition gave considerations to main components of wetland,namely wetland hydrology and vegetation,at the same time,it also made a compromise to wetland inundation time and ways.Wetland soil has many environmental functions,include sustaining biodiversity,distributing and regulating surface water,decomposing and degrading pollution and conserving history and culture relic.But the holistic studies on wetland soil function assessment are scarce,function assessments of wetland soil mostly focus on the single function,not the holistic function assessment.Combined with the soil environment function indicators and Analytical Hierarchy Process,the system of wetland soil function assessment was built up.In a word,the wetland soil definition was discussed,the ecology function,mass source and sink function,nutrient pool function,purification function and memory function were explicated,at the same time,index system and means of environment function assessment of wetland soil were built up.Study on wetland soil and environment function assessment will further confirm wetland soil definition, understand the important place of wetland soil,enrich the theory system of wetland sciences.