| Ecological and environmental effects and mostly ecosystem services functions due to vegetation restoration were regarded as the critical factors for maintain for sustainable development for vegetation restoration on the Loess Plateau.Vegetation restoration promoted soil restoration and the improvement of ecosystem services.In turn,soil restoration and the improvement of ecosystem services are conducive to vegetation reconstruction.However,this is only a series of progresses in stages,and the long-term effects of vegetation restoration on ecosystem service functions still need to be further studied.Here,we selected Zhifanggou,Fangta,Dongzhuanggou and Yangjiagou four typical small watershed on the Loess Plateau,and assessed soil conservation,carbon storage,water conservation and habitat quality by using remote sensing interpretation data,including the measurement data,rainfall data,social and economic data from 1998 to 2018.Thereafter,we explored the characteristics and spatial distribution of ecosystem service tradeoffs of these typical small watersheds,which are benefit to ecological development and environmental protection in terms of vegetation restoration on the Loess Plateau.We get these conclusions:(1)We found that vegetation restoration promoted soil nutrients(including available nutrients)and microbial community diversity in different typical small watershed,and soil nutrients and and soil microbial community diversity showed the synergy pattern due to soil nutrients provide a nutrient source for soil microbial communities,further,this synergy pattern was reflected in different land use types in each watershed.Specially,soil total porosity was higher in cultivated land,artificial grassland and artificial forestland,and lower in natural grassland,artificial shrub and natural shrub in terms of zhifanggou and fangta,while there was an opposite trend in dongzhuanggou and yangjiagou.Soil moisture and organic carbon content was lower in artificial grassland,and higher in natural grassland in terms of zhifanggou and fangta.In dongzhuanggou and yangjiagou,soil moisture and organic carbon content ordered as natural grassland > artificial forest > shrub > cultivated land.Similarly,soil available nutrients showed the same change trend with soil organic carbon.Moreover,soil microbial diversity(Shannon and Simpson)showed artificial shrub >natural shrub > artificial forest > natural grassland > artificial grassland in terms of zhifanggou and fangta,and natural grassland > shrub > artificial forestland > cultivated land in dongzhuanggou and yangjiagou.In these watersheds,Actinobacteria,Proteobacteria,Chloroflexi and Acidobacteria was the main bacterial community,and the average abundance of Actinobacteria in natural grassland was higher,while the average abundance of Proteobacteria in cultivated land was higher.Ascomycota and Basidiomycota was the main fungal community,and the average abundance of Ascomycota in natural grassland and shrub was higher,while the average abundance of Basidiomycota in cultivated land and artificial grassland.The results indicated that in the Loess Plateau,regardless of regional differences and the difference of land use change,the main distribution of microbial community community,has a certain similarity,and different land use has led to the relative abundance of the different microbial communities is different,different typical small watershed soil nutrient(except for total phosphorus)and microbial community Shannon index has significant linear correlation.(2)We also found that vegetation restoration promoted NDVI and NPP in different typical small watershed.NDVI and NPP showed a consistent trend from 1998 to 2018 in these watershed,and NDVI increased slightly from 1998 to 2008,while increased sharply from 2008 to 2018 with fluctuation.Actually,from 1998 to 2018,the area of grassland in zhifanggou increased(the increasing proportion was 33.84%),and the increased rate in2008-2018 was higher than that in 1998-2008,while the area of cultivated land,terrace and shrub decreased,mainly turning to grassland and foresland.The area of grassland(the increasing proportion was 10.05%),forestland(the increasing proportion was 34.57%)in fangta increased,but terrace and cultivated land decreased,mainly turning to grassland,shrub and forestland.The area of forestland and grassland in dongzhuanggou increased,while the area of cultivated land decreased.The cultivated land was mainly converted to forestland and grassland,and the converted proportion was about 7.99% and 15.22%respectively.The area of forestland in yangjiagou increased,while the area of grassland decreased.The grassland was mainly converted to forestland,and the converted proportion was about 37.01%.(3)Natural factors and land use changes were the main driving factors to NDVI and NPP in different typical small watershed.NDVI and NPP were negatively related with temperature and evaporation(P<0.01),and positively related with rainfall(P<0.01),and negatively related with total population(P<0.05).Grey correlation analysis showed that temperature,rainfall and total population had a higher comprehensive correlative degree(0.913,0.926 and 0.903),which had a large contribution to NDVI and NPP in zhifanggou and fangta,while temperature and rainfall had a large contribution to NDVI and NPP in dongzhuanggou and yangjiagou.Further,the net variation in forestland had a largecontribution to NDVI and NPP in zhifanggou and fangta,and the net variation in grassland had a large contribution to NDVI and NPP in dongzhuanggou,and the net variation in forestland had a large contribution to NDVI and NPP in yangjiagou.However,the net variation in cultivated land,construction land and unutilized land had small contribution to NDVI and NPP.(4)We also found that vegetation restoration promoted ecosystem services functions(Soil conservation,carbon storage,water yield and habitat quality)in different typical small watershed,and ecosystem services functions increased sharply from 1998 to 2008,while increased slightly from 2008 to 2018 with fluctuation.Although the progress of vegetation restoration was nonsynchronous with the increasing of ecosystem services functions,vegetation restoration and ecosystem services functions showed the synergy pattern.In addition,the habitat quality of most regions in these four typical small watershed increased,and the spatial habitat quality also increased,mainly due to the project of grain for green in the past 20 years.(5)There was a higher important area of soil conservation in these watershed,which should be protected.In particular,land use types had a large effect on ecosystem services function.Ecosystem services function in forestland,shrubs and grassland in zhifanggou and fangta increased,cultivated land and bare land decreased,and building land and roads remain unchanged with lower ecosystem services function.Ecosystem services function in forestland and grassland in dongzhuanggou and yangjiagou increased,and building land,bare land and roads remain unchanged with lower ecosystem services function.The proportion of the general important area of soil conservation was relatively higher,and then important area in zhifanggou and fangta.The proportion of the general important area of soil conservation was relatively higher,and then important area in dongzhuanggou and yangjiagou.(6)Natural factors and economic characteristics were the main driving factors to ecosystem services functions in different typical small watershed.We found that the regression coefficients about the total population and evaporation capacity to soil conservation function were negative in artificial forestland,artificial shrub and natural shrub in zhifanggou and fangta,while the regression coefficients about the total population and GDP to soil conservation function were positive in cultivated land and natural grassland.The regression coefficients about the total population and evaporation to carbon storage and soil conservation function were negative in artificial forestland and shrub,while the regression coefficients about the total population and GDP to carbon storage and soil conservationfunction were negative in cultivated land and natural grassland.The results of the regression coefficients in habitat quality was same in these watershed,besides,plant diversity had a large effect on habitat quality in these watershed.In addition,vegetation characteristics,soil nutrient characteristics,soil physical characteristics and other natural environmental factors also were the important driving factors to ecosystem service function.(7)Together,we found both of tradeoff and synergy among ecosystem service functions in different typical small watershed,while the pattern of synergy was dominant.It showed mutual promotion in time scale and mutual constraints in spatial scale.In doing so,it can be benefit to maintain the balance of the functions of the ecosystem in this region.Concretely,in 1998,ecosystem service integration exhibited synergy in zhifanggou,and exhibited tradeoff in 2008 and 2018.In fangta,ecosystem service integration exhibited tradeoff in1998 and 2018,while exhibited synergy in 2008.In dongzhuang and yangjiagou,ecosystem service integration exhibited tradeoff from 1998 to 2018.There was a significant positive correlation between carbon storage function and water conservation function(P<0.05),and significant positive correlation between water yield and water conservation function(P<0.05),while no significant correlation between habitat quality and other ecosystem service function(P>0.05),suggesting that habitat quality had a strong spatial heterogeneity.In addition,there was a difference in ecosystem service function in the same land use type,and there was a difference in land use type in the same ecosystem service function.In total,soil water conservation,carbon storage and soil conservation showed synergy of the same increase with the same decrease.This was the main reason that ecosystem service functions increased or decreased in different degrees during the periods of vegetation restoration,thus resulting in that the shifts of ecosystem service functions were not synchronized with vegetation restoration at spatial and temporal scale,and then some kinds of ecosystem service functions showed the synergy and tradeoff at spatial and temporal scale.Although,we found the shifts of ecosystem service functions were not synchronized with vegetation restoration,vegetation restoration promoted and improved ecosystem service functions from1998 to 2018.The main function of ecosystem services showed the synergistic relationship,while some local region showed tradeoff among ecosystem service functions.In doing so,it can be benefit to maintain the balance of the functions of the ecosystem in this region. |
PDF Full Text Request