Effect Of Soil Environment On Soil Organic Carbon Concentration In Dadugang Forest Xishuangbanna

Soil organic carbon(SOC)is the largest carbon pool in terrestrial ecosystems.Its decomposition and release are one of the important causes of climate change.Forest ecosystems are important carbon pools and sinks of terrestrial ecosystems.Therefore,increasing forest soil carbon sequestration is of great significance in mitigating climate change.In this study,the tropical monsoon broad-leaved forest with acid red soil,located in Dadugang,Xishuangbanna,was selected as the research object.Stratified sampling to measure and analyze forest SOC,soil basic physical and chemical environment,soil element,soil mineral,microbial and other parameters in 0-140 cm soil layer.Try to identify the main factors and secondary factors by exploring the weight of each soil environmental factor affecting the forest SOC in the area2The research results can provide a scientific basis for the rational use of forests and increase carbon sequestration in forest soils and reduce carbon losses in forest degradation.The main conclusions are as following:(1)In the basic physical and chemical environment of soil,soil water content.pH and salinity are important factors affecting forest SOC storage,and SOC was positively correlated with soil water content and salinity(p<0.01).High soil water content can reduce the transport efficiency of O2 and accelerate the degradation of organic matter to form SOC.The strong acidity of the soil can decrease the microbial activity and increase the SOC storage,which was negatively correlated(p<0.01).(2)The SOC concentration was positively correlated with TN,TP,C/N,Mn,S,Si(p<0.01),and negatively correlated with Fe and Al(p<0.01).Si element promotes SOC stability through feedback regulation of Si-Fe and Si-A1 in the geochemical silicon cycle.The soil minerals,especially Fe,affect the storage of forest SOC.The SOC concentration was positively correlated with Fe.and Fep,but negatively correlated with Fed(p<0.01).Fe.and Fep have large specific surface area and can adsorb negatively charged organic matter.(3)Among the soil environmental factors affecting forest SOC.the weights from large to small are:Ec(?=12.5%,the effects of Ec accounted for 12.5%of the soil environmental effects,the same as the following),TN(?=11.6%),pH(?=10.6%),S(?=10.3%),TP(?=10.0%),microorganisms(?=9.2%),water content(?=8.4%)and C/N(P=7.5%),AI(?=7.3%),Fe(?=6.8%),Si(?=5.8%).Other soil environmental factors had no effect on the storage of forest SOC.According to the above main and secondary factors affecting forest SOC,the carbon sequestration of forest soil is improved by strengthening soil water retention,enhancing the input of nutrient elements and preventing soil alkalization.