Effects Of Vegetation Restoration On Soil Organic Carbon Content In Loess Plateau

Soil carbon is an important part of global carbon cycle,the way of land use change will change to a great extent of soil carbon sequestration.The large-scale conversion of farmland to forests in loess plateau will have an important influence on regional carbon cycle by affecting soil organic carbon content,but the degree of influence is not clear.By reading lots of literatures and related research,combined with the national soil census and other data of land resources on the loess plateau region,the soil organic carbon content change and control factors such as:plant age,type of afforestation,such as climate and terrain conditions,the combination of quantitative analysis of the process of returning farmland to forest project in the loess plateau of the 0-60 cm,the change of the soil organic carbon content.The change of soil carbon reserve in the field of returning farmland to forest was forecasted.(1)Both water and temperature factors play an important role in the change of soil organic carbon content.Regional soil organic carbon in different temperature and the correlation of temperature and precipitation factors are different,in which the correlation of soil organic carbon and temperature difference is greater than the correlation of soil organic carbon and precipitation.When the temperature is less than 10?,the strongest correlation between soil organic carbon and temperature,when the temperature is greater than 20? when soil organic carbon and climate factors of the correlation of two variables,namely the temperature and precipitation in the worst,and was not significant.(2)Soil organic carbon content index under a variety of ways of land use,has significant differentiation performance:the highest index in natural grassland,centered arbor forest and shrub land,orchard and wasteland compared to a minimum.According to the analysis,the average index in 0-60 cm soil can reach 9.31 g kg 1,due to the storage of the natural grassland and woodland proportion in the total reserves of 80%,so you can think it has stronger ability of carbon sequestration.Through the analysis of the research above,still can get a preliminary conclusion:for the loess hilly-gully region,there are still a variety of channels can make its gradual degradation of ecosystem was restored,such as afforestation and returning farmland to forest or grassland,it mainly restore mentality to adjust land use structure.(3)Terrain factors mainly reflects in the altitude,slope direction,slope on soil physical and chemical properties,the influence of the loess plateau region,in terms of slope direction,slope soil organic carbon content is usually performed better than sunny slope,on half sunny slope and slope in the same way;Generally,the slope is better than the other slope;Moreover,the higher the elevation,the lower the organic carbon content in the soil.(4)The organic carbon content of soil in the loess plateau region is predicted to be stable with the stability of vegetation communities,and the soil organic carbon content will be stable when the returning farmland to forest and grassland reaches a certain stage.Organic carbon on the loess plateau in 2035 will reach 1179.60 Tg after 2035 because of the restriction of certain conditions,returning farmland to forest and grass vegetation or soil growth started to degradation,soil organic matter content less,resulting in a decline in soil carbon.At this time,effective vegetation renewal and maintenance measures are particularly important.Maintaining the stability of soil organic carbon content in the loess plateau region through maintenance measures will become the focus of the project after 2035.