| Forest fire is one of the important disturbance factors of forest ecosystem and one of the important ecological factors that drives the carbon cycling of forest ecosystem.In this study,we selected research plots in the area that after moderate fire disturbance of Maoer Mountain Experimental Forest,and selected the nearby unburnt area as control plots.Soil respiration(Rs)flux was measured by Li-6400 from May 2017 to April 2018 and trench method was used to measure soil heterotrophic respiration(Rh)in this study.The method measures the soil isoxia respiration,quantifies and separates the soil respiration in the growing and non-growth seasons of the secondary forest forest ecosystem after moderate fire disturbance,and quantitatively analyzes the soil microbial biomass after the fire,revealing the moderate fire disturbance.Dynamic changes of soil respiration components and soil microbial biomass during the growing and non-growing seasons of the year.The results of this study will provide a data basis for the quantitative analysis of soil respiration and its components in the forest ecosystem of Maoershan area after fire disturbance,and provide a scientific basis for revealing the carbon cycle changes of secondary forest ecosystems after fire disturbance.Research indicates:1)There is no significant difference in the rate of soil respiration(Rs)between the burned areas and the control plots after a moderate fire.The analysis of soil respiration components showed that the rate of soil heterotrophic respiration(Rh)increased by about 18.6%and the rate of soil autotrophic respiration(Ra)decreased by about 41.9%(P<0.05).The rate of soil respiration(Rs)increased by about 18.3%,the rate of soil oxygenation respiration(Rh)increased by about 29.2%,and there was no significant difference in soil autotrophic respiration(Ra)rate.2)Temperature is the main environmental factor that controls the changes in soil respiration composition in the area.Compared with the control plots,the Q10 of Rs,Rh,and Ra after fire decreased in the growing season,indicating that the secondary forest ecosystem in the Maoershan area was less sensitive to temperature changes in the short term after moderate fire disturbance;Compared with the control plots in the non-growth season,the Q10 of Rs and Rh decreased after fire,and the Q10 of Ra increased,but the temperature of the control plot was not the main environmental factor controlling the autotrophic respiration of the soil in the region(P>0.05).3)In addition,quantitative analysis of soil microbial biomass in the growing and non-growth seasons of the secondary forest forest ecosystem after moderate fire disturbance showed that the soil microbial biomass carbon(MBC)increased by about 5 cm and 10 cm after the growing season.31.2%and 7.3%;soil microbial biomass carbon(MBC)of 5cm and 10cm after non-growth season fire decreased by about 37.5%and 19.0%respectively. |
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