大兴安岭火烧迹地天然次生林土壤微生物生物量及酶活性特征研究OA北大核心CSTPCD

Studying the variation patterns of soil microbial biomass and enzyme activity during the vegetation recovery processes of burned areas,providing a scientific basis for reforestation approaches and effectiveness assessment in burned forests.The three dis-tinct types of Larix gmelinii seed tree-Betula platyphylla forests(MB),understory nursery-Betula platyphylla forests(FB),and Betula platyphylla forests(BB)in the severely burned areas in Daxing'an Mountains were selected as the research objects,with Larix gmelinii plantation(LL)served as a control.The soil microbial biomass carbon(MBC),microbial biomass nitrogen(MBN),and the activities of urease(URE),acid phosphatase(ACP),sucrase(SUC),and catalase(CAT)at depths of 0-5,5-10,and 10-20 cm were measured.Results showed that:1)The variations in soil MBC and MBN ranged from 239.16 to 852.09 mg/kg and 37.08 to 114.99 mg/kg,respectively.The order of MBC and MBN content was MB>FB>LL>BB,except for the 10-20 cm soil layer.2)The ac-tivities of ACP,CAT,and URE were highest in MB.In FB,the average activities of ACP,SUC,and CAT were higher than those in LL,while the average activities of URE and ACP in BB were lower than those in LL.3)Redundancy analysis showed that the interpre-tation rates of soil enzyme activities reached 46.8％,24.9％and 4.5％for 0-5 cm SOC,SAP and MBN,and 61.8％,11.4％and 4.0％for NO3--N,pH and MBC in 5-10 cm soil layer.The interpretation rates of NO3--N,pH and TN in 10-20 cm soil layer were 53.3％,14.7％and 12.4％,respectively.Retaining trees with reproductive capacity as seed trees after a wildfire and implementing timely nurturing management have a positive promoting effect on soil microbial biomass and enzyme activity,contributing to the recov-ery of vegetation in burned areas.