Study On The Effect Of Grassland Road Construction Disturbance On Organic Carbon Content In Central And Western Inner Mongolia

With the rapid development of highway traffic in Inner Mongolia,the highway construction process has frequently disturbed the grassland ecosystem,and different disturbance methods have disrupted the balance of the grassland ecosystem,especially affecting the carbon sink function of the ecosystem.The self-regulation ability of grassland ecosystem in central and western Inner Mongolia is weak,and the factors affecting the carbon sink function of grassland ecosystem are complex and diverse."The present study is based on fieldwork.Therefore,based on the field survey and indoor experimental analysis,this study comprehensively grassland highway construction disturbance methods,through redundancy analysis,correlation analysis and other analytical methods,to investigate the main factors affecting the change of grassland ecosystem carbon sink function due to four kinds of disturbances in the process of highway construction in two grassland areas in Inner Mongolia,such as road embankment,road graben,soil extraction site,and crushing,and analyze the change of grassland ecosystem carbon sink function under different restoration years(1a,5a,15a),The restoration characteristics of soil and vegetation in the disturbed area under different restoration years(1a,5a,15a)were analyzed.The conclusions of the study are as follows:(1)Among typical grasslands and desert grasslands,four types of disturbances,namely,road embankment,road graben,soil extraction site and crushing,all reduce the carbon sequestration capacity of grassland ecosystems to some extent.Among them,road embankment disturbance has the least effect on the carbon sequestration capacity of grassland ecosystem,which is 19.23% higher than that in the native undisturbed area and 66.75% lower than that in the typical grassland,while crushing disturbance is the most serious and reduces the carbon content of the ecosystem the most,which is57.69% lower than that in the typical grassland and 77.33% lower than that in the undisturbed area in the desert grassland.(2)After 1a,5a and 15 a of road construction disturbance,the organic carbon content of the ecosystem increased with the increase of restoration years,and its carbon sequestration capacity also increased.The organic carbon content of the typical grassland increased by 38.57% and that of the desert grassland decreased by 14.45%during the restoration period of 1a-5a;the growth rate was slightly faster during the restoration period of 5a-15 a compared with the previous period,and the organic carbon content of the typical grassland increased by 51.56% and that of the desert grassland increased by 18.26%.(3)Among typical grasslands,Simpson dominance index and above-ground biomass of vegetation had the greatest influence on ecosystem organic carbon content,while among desert grasslands,Simpson dominance index and Margalef richness index had the greatest influence on ecosystem organic carbon content.Soil capacity,above-ground vegetation biomass and Simpson dominance index were the main influencing factors of ecosystem carbon sink function.