Effects Of No Litter?Root Cutting And N Addition On Soil N₂O/CO Flux In Natural Larix Gmelini Forest

Larix gmelini forest is the largest virgin forest in Da Xing'an Mountains in China,N₂O and CO emissions directly affect the source and sink functions of forests for greenhouse gases.This experiment selected this typical Larix gmelini forest in cold temperate zone to explore the relation between remove litter,root cutting and N addition with different concentrations on the N₂O and CO gases,using dynamic chamber in 2020growing season June-September fixed-point observation,to analyze the time variation characteristics of the two gases,and different disturbance's influence on the N₂O and CO emissions.As the main ways of soil carbon input,litters and roots not only affect the carbon cycle,but also regulate greenhouse gas emissions by changing soil physical and chemical properties.Artificial simulation of nitrogen deposition determines the effect of N addition on greenhouse gases N₂O and CO emissions.In conclusion,this experiment aims to comprehensively understand the effects of remove litter,root cutting and N addition interference on soil N₂O and CO emissions by combining the two gas fluxes and environmental factors(soil temperature and humidity)measured by different carbon and nitrogen input disturbances.(1)To clarify the effects of different disturbances on soil temperature and soil moisture.No litter and root cutting had a slight effect on soil temperature but no significant difference(P>0.05),and had a certain effect on soil moisture with a significant difference(P<0.05).No litter and root cutting did not affect the temporal variation characteristics of soil temperature and moisture.Soil temperature and soil moisture had no significant differences under different concentrations of N addition disturbance,and N addition disturbance also did not change the temporal variation characteristics of soil temperature and soil moisture.(2)To clarify the effects of different disturbances on soil N₂O flux.No litter and root cutting would decrease soil N₂O flux,but the difference was not significant(P>0.05).The contribution of litters to soil N₂O gas flux was higher than that from plant roots.Different concentrations of N addition had different effects on N₂O flux.In a short time,low and medium N addition had an effect on soil N₂O flux but the difference was not significant(P>0.05),while high N added significantly increased soil N₂O emission flux difference was significant(P<0.01).(3)To clarify the effects of different disturbances on soil CO flux.Both litter and plant roots increased soil CO flux,and the differences were significant(P<0.05).The contribution of litter decomposition to soil CO gas flux was higher than plant roots to soil CO.Soil CO flux was not affected by N addition at different concentrations(P>0.05).(4)Explored the coupling relationship between soil CO flux and N₂O flux.Due to the complex interaction between the sources of N₂O and CO and microorganisms and soil enzymes,there may be a influence relationship.Through experimental observation,the linear regression equation of soil N₂O and CO is Y=0.0315X-2.427(R²=0.055,P>0.05),there was no significant linear regression relationship between the two,and the degree of mutual influence was weak.