Study On Water Supply And Soil Conservation Service Function Of Different Carbon Sequestration Model

Different afforestation patterns have different effects on forest ecosystem service,based on the InVEST model,water supply and soil retention functions of three afforestation patterns(closing hillside afforestation,intercropping planting,new afforestation)were evaluated in this paper.The optimal model and the worst mode of forest water supply and soil retention service function under different afforestation patterns were conducted,proposed to provide scientific basis for management of forest carbon sequestration ecological engineering.The main results of this paper are as follows:(1)The actual evapotranspiration of the study area under the three afforestation patterns was in the order of supplemental interplanting> new afforestation> closing hillsides,in the early stage of carbon sequestration(3 to 4 years of carbon storage forest),the actual evapotranspiration in the study area is the highest.However,from the point of view of the actual evapotranspiration growth,the actual evapotranspiration will be smaller for the new afforestation relative to the hillsides and fertilizers.In different period,the spatial distribution of the same afforestation model had significant decrease in the area where the actual evapotranspiration was low,but the spatial distribution is basically stable in general.In the same period,the spatial distribution under the same afforestation patterns was basically the same,only the numerical value of the actual evapotranspiration changed.(2)The water supply of the three afforestation patterns was in the order of supplemental interplanting> new afforestation> closing hillsides.In the early stage of carbon sequestration,the supply of carbonaceous forest was the highest.During the period from 2015 to 2016,the growth of water supply in the three afforestation modes increased from large to small,followed by planting intercropping> new afforestation> closing forest.Therefore,from the point view of the increase in the supply of water,the supply of water supply from the supplementary forest and the new afforestation model will be more favorable.In different period,the spatial distribution of water supply of the same afforestation model has a significant change,mainly in the eastern and northern areas of the study area.In the same period,under different afforestation patterns,the spatial distribution of the vegetation was decreasing from the northwest region to the southeast region.Only the value of the water supply was changed and the changeable land use type was only forestry land,while the other land types were stable.(3)Three kinds of afforestation patterns of soil erosion was in the order of new afforestation> replanting intercropping> closing hillsides,soil retention was conversely,in the early stage of carbon sequestration,using closed forestation afforestation model,the soil retention was higher than the new afforestation and replanting intercropping model of carbon sinks.During the period of 2015-2016,the increase in soil erosion in the three afforestation patterns was in order of: the closure of afforestation> supplemental planting> new afforestation,and the increase in soil conservation was conversely.Therefore,from the point of view of soil erosion and soil conservation,the growth rate of soil holdings of supplemental intercropping and new afforestation patterns was higher than that of closed hillsides,but the soil erosion rate of interplanting and new afforestation model was not lower than the closed forest.The spatial distribution of soil conservation has changed significantly under the same afforestation mode during different periods,the spatial distribution of soil conservation has changed from decreasing from northwest to southeast area in 2015 to decreaseing from south to north in 2016.But the spatial distribution of soil conservation under different afforestation mode was basically the same during the same periods,only the numerical value of soil conservation was changed.The changeable land use type was only forest land,while the other land types were stable.