Wetland Ecosystem Services Evalution Based On The InVEST Model

Wetland ecosystem service function provides and maintains the earth's life system,which is the necessary ecological condition for the survival and development of human society.It plays a supporting role for human and social development.Scientific and rational assessment of the functions of wetland ecosystem can provide scientific basis for the protection and management of wetlands.Dazhanhe wetland is a National Nature Reserve dominated by marsh wetland,and it is also an important ecological barrier and water conservation area in Heilongjiang basin.Based on remote sensing and GIS technology,this paper uses InVEST model to dynamically evaluate the water supply,carbon storage and biodiversity functions of Dazhanhe Wetland Nature Reserve in 1996,2005 and 2017,and discusses three kinds of organisms in different periods.The spatial change of ecological service function and the ecological function under different land cover were analyzed.Finally,the importance zoning was carried out by integrating various ecological service functions.The main results are as follows:(1)The main types of LULC in the study area are forest land and marsh wetland.From 1996 to 2005,the area of marsh wetland shifted to forest land and grassland.From2005 to 2017,natural resources such as wetland were effectively protected,and the area of marsh wetland rose.(2)The water supply in the third stage of the study area shows a trend of increasing gradually from northwest to southeast.Overall,the water supply has decreased first and then increased in the past 20 years,and the water supply function has been gradually improved.Grassland and coniferous forest have the strongest water supply capacity per unit area,and swamp wetland,deciduous broad-leaved forest and coniferous broad-leaved mixed forest have the most obvious water supply function.(3)From 1996 to 2017,the spatial distribution pattern of carbon storage function in the study area changed little.The high value area of carbon storage function was located in the South and central part of the study area,while the low value area was distributed in the northeast,southwest and southeast.The lowest value area was river and lake bubbles.Total carbon storage decreased first and then increased.Marsh wetland is the most carbon storage land type.(4)From 1996 to 2017,the spatial distribution pattern of habitat quality in the study area was basically the same.The areas with higher habitat quality were mainly distributed in the southeast and north,and the overall trend of the habitat quality index was rising.The richness of shrub community and meadow community was the highest,the diversity of meadow and swamp community was the highest,and the evenness index of broad-leaved forest community was the highest.(5)In 2017,the three ecosystem service functions of water supply,carbon storage and biodiversity in the study area were 12458.52 hm~2,which accounted for 5.85%of the total area of the study area.The distribution of the three ecosystem services in the study area was scattered,and the terrain was relatively high.The land cover was mostly coniferous and broad-leaved mixed forest and deciduous broad-leaved forest.