Habitat Risk Assessment Of Winter Waterfowls In Coastal Wetlands Under The Influence Of Coastal Reclamation

With the development of coastal economy,coastal areas are gradually becoming the most densely populated areas,and coastal land resources are in short supply.Coastal reclamation has become an effective and a common way to acquire land resources and develop coastal economy.A large amount of sea surface was reclaimed for agriculture,aquaculture,industry,port and urban construction.In addition,the tidal flat wetlands close to the sea were also occupied,and the number of coastal wetlands decreased sharply.However,the conditions of coastal wetland determine the distribution of species composition and the size of waterfowls' population,which will affect the community structure of waterfowls.Carry out habitat risk assessment of winter waterfowls under the influence of coastal reclamation,visualize risks and analyze the policy effectiveness of current coastal reclamation is of great research value in the aspect of assessing the risks of winter waterfowl habitat,managing coastal reclamation activities in winter waterfowl habitats and improving coastal reclamation policies.This research selects habitats of winter waterfowls in the megalopolis Minsanjiao as an object,coastal reclamation as a pressure,based on land use types of coastal reclamation in megalopolis Minsanjiao,observation data of winter waterfowls,mudflat data as well as spatial data of the National Marine Functional Zoning,spatial distribution data of the National Nature Reserve,selecting criteria from three dimensions-exposure,sensitivity an d resilience,utilizing InVEST HRA model to assess the risk of winter waterfowl habitats in the megalopolis Minsanjiao in the year 2006 and 2017,calculating the value of risk,exposure and consequence of winter waterfowl habitats in the megalopolis Minsanjiao,and mapping the risk distribution.Based on the evaluation results of the InVEST HRA model,combining with the Monitoring and Evaluation of Spatially Managed Areas(MESMA)framework,this study evaluates the policy effectiveness of coastal reclamation in winter waterfowl habitats in the megalopolis Minsanjiao,and provides suggestions for management policies of coastal reclamation.The main contents and conclusions of this study are as follows,(1)Land use pattern of coastal reclamation and distribution of winter waterfowl species in the megalopolis Minsanjiao.In 2006 and 2017,land use types of coastal reclamation in the megalopolis Minsanjiao included paddy fields,aquaculture,bare land,urban land,port and dock,etc.The total area of coastal reclamation in 2006 was 61.05 km2,and 153.11 km2 in 2017,which increased 92.05 km2 comparing with that in 2006.In 2006,the coastal reclamation area in winter waterfowl habitats within each bay ranging from large to small was Xiamen bay>Xipu salt farm>Quanzhou bay>Duxun salt farm>Weitou bay>Zhao 'an bay>Jiulong river estuary>Zhangjiangkou mangrove forest>Shenhu bay.In 2017,the coastal reclamation area in winter waterfowl habitats within each bay ranging from large to small was Xiamen bay>Quanzhou bay>Xipu salt farm>Duxun salt farm>Weitou bay>Zhao 'an bay>Zhangjiangkou mangrove forest>Shenhu bay.The species of winter waterfowl in the megalopolis Minsanjiao are mainly waders,gulls,anatidae,cormorants and herons,among which waders are the dominant population.Their main habitats are concentrated in Quanzhou bay,Weitou bay and Xiamen bay;(2)Risk assessment of winter waterfowl habitats in the megalopolis Minsanjiao based on In VEST HRA model.In 2006,the total risk area of winter waterfowl habitats in the megalopolis Minsanjiao was 20.34 km2.Risk areas were scattered in winter waterfowl habitats,mainly the low risk and the high risk.In 2017,the total risk area of winter waterfowl habitats in the megalopolis Minsanjiao was 56.55 km2,which increased 36.21 km2 comparing with the area of 2006.In 2006 and 2017,the land use type of coastal reclamation which has the highest risk value in winter waterfowl habitats in the megalopolis Minsanjiao was aquaculture.In 2006,the land use type of coastal reclamation which has the lowest risk value in winter waterfowl habitats in the megalopolis Minsanjiao was shallow water;in 2017,it was shallow water and waste land.In 2006,the exposure value and the consequence value caused by coastal reclamation to winter waterfowl habitats in the megalopolis Minsanjiao were 2.03 and 1.34 respectively.In 2017,the exposure value and the consequence value caused by coastal reclamation to winter waterfowl habitats in the megalopolis Minsanjiao were 1.78 and 1.58 respectively.The exposure and consequence of different land use types of coastal reclamation to winter waterfowl habitats in each bay area were different;(3)Evaluation of the management effectiveness of coastal reclamation policies and policy suggestion based on the framework of Monitoring and Evaluation of Spatially Managed Areas.The effectiveness of reclamation management policies needs to be improved due to the increase of coastal reclamation area and the lack of targeted measures.Based on the actual situation,the following suggestions are put forward for coastal reclamation policies:management policies of coastal reclamation and the normalization of coastal reclamation projects should be implemented specifically for winter waterfowl habitats;For the waterfowl habitat that has been enclosed,the appropriate habitat for the corresponding area should be compensated;advocating that farmers should not cover the fishponds with anti-bird nets,and provide certain subsidies according to the area without covering anti-bird nets.Coastal reclamation has caused influence on coastal wetlands which are reliable habitats for winter waterfowls,the clustering and easy-to-see attribute of waterfowls makes them a good indicator for the ecological environment quality.Therefore,assessing habitat risk of winter waterfowls in coastal wetlands,making clear the spatial distribution of risk degree and risk status,can not only directly reflect the habitat status of winter waterfowls in coastal wetlands,but also indirectly reflects the status of coastal wetland ecosystem.Besides,this study aims at the coupling system of coastal reclamation and winter waterfowls in coastal wetland,making the habitat risk assessment of winter waterfowls come true for the first time,making the spatial distribution and status of the risk clear,as well as using the framework of Monitoring and Evaluation of Spatially Managed Areas(MESMA)to realize the evaluation of coastal reclamation' policies and management effectiveness for the conservation of winter waterfowls which has certain innovation.