积雪覆盖变化对大兴安岭白桦次生林土壤微生物生物量和胞外酶活性的影响  

Effects of snow cover changes on soil microbial biomass and extracellular enzyme activities of Betula platyphylla secondary forest in the Daxing’an Mountains

作　　者：任璐 李欣 马大龙[1] 宋丹丹 刘梦洋 REN Lu;LI Xin;MA Dalong;SONG Dandan;LIU Mengyang(College of Geographical Sciences,Harbin Normal University,Harbin 150025,China)

机构地区：[1]哈尔滨师范大学地理科学学院,哈尔滨150025

出　　处：《应用与环境生物学报》2021年第5期1147-1154,共8页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(42171127);黑龙江省普通本科高等学校青年创新人才培养计划项目(UNPYSCT-2017177);哈尔滨师范大学硕士研究生创新项目(HSDSSCX2021-20)资助。

摘　　要：为了解气候变化情景下积雪覆盖减少对土壤微生物的影响,选取大兴安岭白桦次生林为研究对象,采用人工遮雪法,探究不同时期自然积雪和遮雪处理下土壤微生物生物量和胞外酶活性的变化特征及其关键环境驱动因子.结果显示:土壤微生物生物量碳(MBC)在积雪形成期最高、植被生长季初期最低,在积雪稳定期遮雪处理下MBC显著高于对照;在积雪稳定期自然积雪下微生物生物量氮(MBN)显著高于遮雪处理(P<0.05);遮雪对微生物生物量磷(MBP)无显著影响(P>0.05).在积雪稳定期和积雪融化期自然积雪下β-葡萄糖苷酶(βG)活性显著高于遮雪;自然积雪下β-N-乙酰氨基葡萄糖苷酶(NAG)和过氧化物酶(PER)活性均在积雪稳定期显著高于遮雪处理(P<0.05);酸性磷酸酶(AP)活性整体呈先降低后升高再降低趋势;遮雪对多酚氧化酶(PPO)活性无显著影响(P>0.05).遮雪仅在积雪稳定期显著改变土壤微生物生物量和胞外酶化学计量比.冗余分析(RDA)发现,土壤含水率(SWC)、总磷(TP)与MBP、AP呈显著正相关;MBC受土壤总有机碳(TOC)影响较大;铵态氮(NH_(4)^(+)-N)与MBN呈显著正相关(P<0.05);pH是影响NAG、βG的关键环境因子;PER和PPO受环境影响较小(P>0.05).本研究表明土壤微生物生物量和胞外酶活性受短期遮雪干扰后能够快速恢复,微生物可通过调控自身代谢过程来应对全球变化.The Betula platyphylla secondary forest in the Daxing’an Mountains was selected as the research object to understand the impact of reductions in snow cover on soil microbes under climate change scenarios.The artificial snow cover method was used to explore the characteristics of the variation of soil microbial biomass and extracellular enzyme activity and the key environmental factors driving these processes under natural snow cover and snow cover treatments under different periods of change.The results showed that the soil microbial biomass carbon(MBC)was highest during the snow formation period and lowest at the beginning of the vegetation growth season.In the snow-stable period,the MBC used in the artificial snow cover method was significantly higher than that used in the natural snow cover method.In the same period,the microbial biomass nitrogen(MBN)was significantly higher(P<0.05)in natural snow cover conditions than in the snow cover condition.Snow cover had no significant effect(P>0.05)on microbial biomass phosphorus(MBP).β-DGlucosidase(βG)activity was significantly higher under natural snow than snow cover conditions,compared to the others,during periods when snow was stable or melting.During the stable snow cover period,the activities ofβ-N-acetylglucosaminidase(NAG)and peroxidase(PER)were significantly higher(P<0.05)in natural snow cover conditions than in snow cover conditions.The overall acid phosphatase(AP)activity showed a trend of first decreasing,then increasing,and then decreasing again.Snow cover had no significant effect(P>0.05)on the activity of polyphenol oxidase(PPO),and only changed the stoichiometric ratio of soil microbial biomass and extracellular enzymes significantly during the stable snow cover period.Redundancy analysis revealed that soil moisture content(SWC)and total phosphorus(TP)were significantly positively correlated with MBP and AP;MBC was significantly affected by soil total organic carbon(TOC);ammonium nitrogen(NH_(4)^(+)-N)was significantly positively correlated with M

关 键 词：大兴安岭 微生物生物量 胞外酶 积雪 化学计量比 

分 类 号：S714.3[农业科学—林学]