Dynamic Change Of Soil Microbial Biomass In Different Restoration Periods Of The Dahurian Larch (Larix Gmelinii) Forest After Fire

Global warming,the impact of the North Forest is particularly serious,forest fire as an important interference factor in northern China,now more serious impact.Soil microbial biomass responds most quickly to environmental changes.In this paper,3 years after the fire in Daxing’anling,9 years after the fire and 28 years after the fire,the fire area was selected as the control object.The soil microbial biomass in different restoration stages after severe fire was selected as the control.The dynamic changes of soil physical and chemical properties,and the dynamic changes of soil physical and chemical properties.This study provides a data basis for the restoration of forest ecosystem after fire and the mechanism of carbon and nitrogen cycling.The results are as follows:The pH value of the soil（0-20 cm）decreased by 0.65 and 0.35,respectively,and the soil pH was higher than that in the control area,which was 0.34 and the soil acidity Weakened.The content of available phosphorus in soil（0-20 cm）was lower than that in control forest,and decreased by 34.06 mg·kg^-1and 33.6 mg·kg^-1,respectively.The soil available phosphorus was 31.15%after 28 years of fire.The content of available potassium in soil（0-20 cm）was significantly higher than that in control forest（P<0.05）,and 246.81 mg·kg^-1and 456.65mg·kg^-1,respectively.The available potassium content in soil（0-10 cm）The available potassium content in the control forest increased by 13.76 mg·kg^-1,and the available potassium content in the soil（10-20 cm）was 15.13 mg·kg^-1less than that in the soil under the control forest.The soil nitrogen content in the upper layer（0-10 cm）,the lower layer（10-20 cm）and the whole soil layer（0-20 cm）was lower than that in the control area at 3 years and 28 years after fire.Below the control area,with the increase of the recovery period,the soil microbial nitrogen content decreased first and then increased.The carbon content of soil microbial biomass in the soil layer was higher than that in the control area,and the carbon content in the soil layer was lower than that in the control area at 9and 28 years after the fire.With the increase of the recovery period,the soil microbial carbon content decreased Increase,the soil layer and the entire soil layer performance has been reduced.