不同生长阶段尾巨桉人工林土壤-微生物化学计量特征  

Soil-microbial stoichiometry of Eucalyptus urophylla×E.grandis plantation at different growth stages

作　　者：竹万宽 许宇星 王志超 杜阿朋 ZHU Wankuan;XU Yuxing;WANG Zhichao;DU Apeng(National Positioning Observation and Research Station of Eucalyptus Forest Ecosystem in Zhanjiang,China Eucalypt Research Centre,National Forestry and Grassland Administration,Zhanjiang 524022,Guangdong,China)

机构地区：[1]国家林业和草原局桉树研究开发中心,广东湛江桉树林生态系统国家定位观测研究站,广东湛江524022

出　　处：《浙江农林大学学报》2021年第4期692-702,共11页Journal of Zhejiang A&F University

基　　金：广西创新驱动发展专项(桂科AA17204087-9);广东省林业科技创新项目(2018KJCX014);广东省自然科学基金资助项目(2020A1515011404);广东省林业科技创新平台项目(2020-KYXM-09);广东湛江桉树林生态系统国家定位观测研究站运行项目。

摘　　要：【目的】研究幼龄林、成熟林和过熟林阶段尾巨桉Eucalyptus urophylla×E.grandis人工林土壤化学性质及土壤微生物化学计量特征,以丰富桉树林生态系统生态化学计量学领域的基础研究。【方法】以雷州半岛3个处于不同生长阶段的尾巨桉人工林为研究对象,测定0~20、20~40和40~60 cm土层土壤化学性质及土壤微生物碳、氮、磷质量分数,分析土壤及微生物化学计量关系特征。【结果】尾巨桉人工林土壤有机碳、全氮、全磷和土壤微生物碳、氮、磷质量分数均值均以过熟林最高,分别为20.15、1.47、0.88 g·kg^(−1)和583.09、55.20、28.03 mg·kg^(−1),不同生长阶段差异性特征并不一致。土壤有机碳、全氮、全磷和土壤微生物碳、氮、磷质量分数的垂直变化呈现“表层聚集性”特征,不同生长阶段的土层间差异性元素类别表现不一。成熟林土壤碳氮比(C_(soil)/N_(soil))和碳磷比(C_(soil)/P_(soil))均值分别为10.52和19.25,显著低于幼龄林和过熟林(P<0.05);过熟林氮磷比(N_(soil)/P_(soil))均值为1.67,显著低于幼龄林和成熟林(P<0.05)。过熟林土壤微生物碳磷比(C_(mic)/P_(mic))、氮磷比(N_(mic)/P_(mic))均值分别为21.25、2.00,均显著低于其他2个阶段(P<0.05)。不同生长阶段土壤微生物碳与土壤有机碳比值(C_(mic)/C_(soil))无显著差异,土壤微生物氮与土壤全氮比(N_(mic)/N_(soil))和土壤微生物磷与土壤全磷比(P_(mic)/P_(soil))均为过熟林显著低于其他阶段(P<0.05)。冗余分析表明:幼龄林、成熟林和过熟林土壤微生物的首要影响因子分别为C_(soil)、C_(soil)/P_(soil)和N_(soil)。【结论】尾巨桉人工林土壤微生物生物量在过熟林阶段最高,土壤微生物生物量与土壤化学性质关系密切,林分不同生长阶段土壤微生物受土壤影响的指标和程度具有差异性,生长后期应注重养分有效性对土壤微生物生长繁殖的影响。图4表2参54。[Objective]The present study aims to investigate the _(soil)-_(mic)robial stoichiometry of Eucalyptus urophylla×E.grandis plantation at young,mature,and overmature stages in order to enrich the basic research in the field of ecological stoichiometry of Eucalyptus plantation ecosystem.[Method]Three E.urophylla×E.grandis plantations at different growth stages in Leizhou Peninsula were selected as the research objects.Soil samples were collected from 0−20,20−40,40−60 cm _(soil) layers respectively for measuring _(soil) organic carbon(C_(soil)),total nitrogen(N_(soil)),total phosphorus(P_(soil)),_(soil) _(mic)robial biomass carbon(C_(mic)),nitrogen(N_(mic)),and phosphorus(P_(mic)),and the ratio among them was estimated to analyze the relationship between _(soil) and _(mic)robial biomass.[Result]The mean values of _(soil) organic carbon,total nitrogen,total phosphorus and _(soil) _(mic)robial carbon,nitrogen and phosphorus were the highest in overmature forest,which were 20.15,1.47,0.88 g·kg^(−1) and 583.09,55.20,and 28.03 mg·kg^(−1),respectively.The differences in different stages were not consistent.The vertical changes of _(soil) organic carbon,total nitrogen,total phosphorus and _(mic)robial biomass carbon,nitrogen and phosphorus showed the characteristics of"surface aggregation",and the differences among _(soil) layers in different growth stages were different due to different element types.The average values of C_(soil)/N_(soil) and C_(soil)/P_(soil) in mature forest were 10.52 and 19.25,respectively,which were significantly lower than those in young and overmature forests(P<0.05).The mean value of N_(soil)/P_(soil) in overmature forest was 1.67,which was significantly lower than that in young and mature forests(P<0.05).The average values of C_(mic)/P_(mic) and N_(mic)/P_(mic) on overmature stage were 21.25 and 2.00,which were significantly lower than those in other two stages(P<0.05).The ratio of _(soil) _(mic)robial biomass carbon to _(soil) organic carbon(C_(mic)/C_(soil))had no significant diff

关 键 词：森林生态学 化学计量特征 尾巨桉人工林 土壤 微生物 

分 类 号：S792.39[农业科学—林木遗传育种]