Effects Of Fire Disturbance And Biochar Input On Soil Respiration Components Of Pinus Tabuliformis Forest In Checkboard Mesa

The study of soil respiration（Rs）is an important part of the research on changes in the global carbon balance.At the same time,soil respiration is divided into autotrophic respiration（Ra）and heterotrophic respiration（Rh）,and fire disturbance is one of the important disturbance factors in forest ecosystems.First,it is one of the important ecological factors affecting the carbon cycle of forest ecosystems.Biochar is generally considered to be a highly stable organic carbon and is considered an effective strategy for mitigating global climate change,but uncertainties surrounding biochar’s climate mitigation potential remain and there is an urgent need to understand the effects of biochar application on forests.Ecosystems,especially studies on the mechanisms of influence of soil respiration components in forest ecosystems.Therefore,in order to better understand the effects of fire disturbance and biochar addition and the combined effects of fire disturbance and biochar addition on soil respiration components in forest ecosystems,this study selected a fire area in Checkboard Mesa in Shenyang,Liaoning,Northeast my country.Pinus tabuliformis forest,a typical tree species in the region,was selected as the research object.Control plots（C）,low-severity fire disturbance plots（L）and high-severity fire disturbance plots（H）were selected,and different levels of biochar were added(no addition（B0）,low-level biochar addition of 5 tons/ha（B5）and high-level biochar addition of 10 tons/ha（B10）,revealing that under the influence of fire disturbance and biochar addition and their combined effects,soil respiration components and effects of soil physicochemical properties and their regulatory mechanisms.The main results are as follows:（1）Under different severity fire disturbance,the soil Rs,Rh and Ra rates of Pinus tabuliformis forest showed significant seasonal changes.Compared with the control plot,the changes of soil Rs and Rh after low-severity fire interference were not significant,and the rate of soil Ra decreased significantly by 36.13%;after high severity fire disturbance,the rates of Rs,Rh and Ra increased significantly by 38.94%,35.29%and 36.13%.Compared with the control plots,the Q₁₀ values of soil Rs,Rh and Ra rates in the fire disturbance area decreased in varying degrees.（2）Under different levels of biochar addition,the soil Rs,Rh and Ra rates of Pinus tabuliformis forest showed significant seasonal changes.Compared with the control plot,the rate of soil Rs and Rh did not change significantly after the addition of low-level biochar,and the rate of soil Ra decreased significantly by 28.66%;however,after the addition of high-level biochar,the change of soil Rh rate was not significant,and the rates of soil Rs and Ra increased significantly by 23.27%and 51.58%.The Q₁₀ value of soil Rs and Ra rate in the sample plot with low-level biochar addition increased,while the Q₁₀ value of soil Rh rate decreased.The Q₁₀ value of Rs and Rh in the sample plot with high-level biochar addition increased,while the Q₁₀ value of Ra decreased.（3）Compared with the Rs rate of C-B0 sample plot,the soil Rs of L-B5 sample plot decreased significantly,the soil Rs of L-B10 sample plot did not change significantly,and the soil Rs of H-B5 and H-B10 sample plots increased significantly by 31.67%and 46.39%.Compared with L-B0 plot,the Rs and Rh rates of L-B5 plot decreased significantly,but the Ra rate did not change significantly;The rates of Rs,Rh and Ra in L-B10 sample plot did not change significantly.Compared with H-B10 plot,the Rs and Rh rates of H-B5 plot did not change significantly,and the Ra rate decreased significantly by 28.86%.The Rs rate of H-B10sample plot did not change significantly.The Rh rate increased significantly by 27.57%and the Ra rate decreased significantly by 35.79%.By fitting the Q₁₀ value of the equation,it can be seen that compared with C-B0 sample,the Q₁₀value of Rs in L-B5 and H-B10 sample plot,Q₁₀ value of Rh in L-B5,H-B5 and H-B10sample plot and Q₁₀ value of Ra in L-B10 sample plot increase,and the other Q₁₀ values decrease.Compared with L-B0 sample plot,Q₁₀ values of Rs,Rh and Ra in L-B5 sample plot increase,Q₁₀ values of Rs and Ra in L-B10 sample plot increase,and Q₁₀ values of Rh decrease.Compared with H-B0 plot,Q₁₀ values of Rs and Ra in H-B5 plot decreased,Q₁₀values of Rh increased,and Q₁₀values of Rs,Rh and Ra in H-B10 plot increased.To sum up,this study takes the Pinus tabuliformis forest in Checkboard Mesa in the northern temperate zone as the research object to systematically clarify the effects and mechanisms of fire interference and biochar addition on soil respiratory components.It is found that single low-severity fire interference and single low-level biochar addition have no significant impact on soil Rs rate,and single high-severity fire interference and single high-level biochar addition significantly increase soil Rs rate,The addition of low-level biochar after fire disturbance will reduce the soil Rs rate.The addition of low-level biochar in low-severity fire disturbance sample will significantly reduce the soil Rs rate and reduce greenhouse gas emissions.This will help us fully understand the response of carbon sink/source characteristics of soil ecosystem of Pinus tabuliformis forest in northern temperate zone to fire interference and biochar addition,and also provide an important scientific basis for the countermeasures of reducing greenhouse gas emissions after fire in forest fire management.