| Qilihai Wetland is an important part of Tianjin Ancient Coastal and Wetland National Nature Reserve.It is a typical area of biodiversity with a wide variety of organisms,which plays an important role in regulating the local climate and purifying the surrounding environment.However,the ecological environment of Qilihai wetland continued to deteriorate due to human activities with the development of social economy.In order to control this trend,the core area of Qilihai wetland was closed in 2017,and no one was allowed to enter the core area of the reserve.At the same time the wetland ecological restoration project started.This paper further improves the theory and method of wetland ecological restoration effect evaluation,enriches the connotation of its theoretical system,so as to evaluate the ecological restoration effect of wetland more scientifically,reasonably and comprehensively.In this paper,the ecological restoration of water environment,biological community,landscape and landform was evaluated in Qilihai Wetland Reserve,which used the following eight index: sediment,ecologic water compensation,the water environment quality,plankton,terrestrial plant community,birds,landscape naturalness and landscape uniformity,respectively in 2017 and in2020.The evaluation method were time sequence space contrast and fuzzy analytic hierarchy process.In addition,the change trend of each index before and after the project was analyzed to improve the ecological environment of the wetland.The results show that the existing ecological restoration project is effective and feasible.The results are as follows:(1)After the implementation of ecological water replenishing project,the problem of water shortage in Qilihai Wetland Reserve has been slowed down.All enterprises in the surrounding buffer zone were dismantled to reduce the pollution of the wetland water environment caused by industry and aquaculture activity,strictly managing the entry and exit of the wetland core area.These measures have improved the quality of water and sediment to a certain extent in the monitoring in 2020,and the water quality of wetlands has improved significantly.(2)The vegetation coverage in the wetland increases,which in increased by33.7% in 2020 compared to that in 2017.With the wild vegetation restoration effectively,the several bird island has good condition that makes the bird come to habitat.In 2020,the number of bird species and the cumulative number of birds reached the highest in the past five years,reaching 193 species and 125,547 birds,respectively.The diversity index of phytoplankton and zooplankton also show an increasing trend since 2017.(3)After the ecological restoration project,all the fish ponds and aquaculture ponds in the Qilihai wetland have been cleared,the area of green garden has been greatly increased,and the area of building land and traffic road has been greatly reduced,which makes the structural proportion difference among the components of various landscape types decrease.Compared to in 2017,the diversity and homogeneity of Qilihai wetland landscape increased in 2020,and the proportion of natural landscape increased by 14.5%.(4)By use of the fuzzy chromatography analysis,the results show that the comprehensive index of ecological restoration evaluation of Qilihai Wetland Reserve in 2017 was 0.503,and the grade was average,and the comprehensive index of the evaluation in 2020 is 0.687,and the grade is good.The ecological restoration project has restored the overall ecological environment of Qilihai wetland to a certain extent,and the environmental restoration measures have promoted the benign improvement of the wetland ecosystem function and structure. |
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