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林业科学 ›› 2019, Vol. 55 ›› Issue (7): 178-186.doi: 10.11707/j.1001-7488.20190720

• 研究简报 • 上一篇    下一篇

寒温带森林根际土壤微生物量碳氮含量生长季内动态变化

丁令智, 满秀玲, 肖瑞晗, 蔡体久   

  1. 东北林业大学林学院 森林生态系统可持续经营教育部重点实验室 哈尔滨 150040
  • 收稿日期:2018-09-30 修回日期:2019-03-20 出版日期:2019-07-25 发布日期:2019-08-16
  • 基金资助:
    国家自然科学基金项目(31770488)。

Dynamics of Soil Microbial Biomass Carbon and Nitrogen in the Soil of Rhizosphere during Growing Season in the Cold Temperate Forests

Ding Lingzhi, Man Xiuling, Xiao Ruihan, Cai Tijiu   

  1. Key Laboratory of Sustainable Forest Ecosystem Management, Ministry of Education School of Forestry, Northeast Forestry University Harbin 150040
  • Received:2018-09-30 Revised:2019-03-20 Online:2019-07-25 Published:2019-08-16

摘要: [目的]研究寒温带森林根际土壤微生物量碳氮含量的动态变化,为揭示森林土壤碳氮养分利用机制和碳氮循环提供参考,为研究区森林保护与合理经营提供科学依据。[方法]以我国寒温带针阔混交林为研究对象,选择主要组成树种樟子松、兴安落叶松、白桦和山杨,采用抖落法采集根际和非根际土壤样品,对土壤微生物量碳氮含量动态特征进行研究,探讨不同树种根际土壤微生物量碳氮的富集程度、差异性和生长季变化以及其对土壤营养库的贡献率。[结果]不同树种根际土壤微生物量碳氮含量月际变化差异显著,根际土壤微生物量碳含量波动范围为114.14~451.05 mg·kg-1,氮含量波动范围为40.38~185.00 mg·kg-1。根际土壤微生物量碳富集率依次为樟子松(87.99%) > 白桦(78.22%) > 兴安落叶松(73.14%) > 山杨(56.96%),微生物量氮富集率依次为山杨(81.50%) > 白桦(77.63%) > 樟子松(76.42%) > 兴安落叶松(51.40%)。土壤微生物量碳氮比为1.42~5.24,樟子松、兴安落叶松、白桦、山杨根际和非根际土壤微生物量碳氮比生长季变幅分别为1.42~5.24、1.57~3.79、1.67~4.55、1.55~2.59和1.79~3.53,其均值分别为2.64、2.63、2.81、2.11和2.36。根际微生物量碳对土壤有机碳库的贡献率为0.83%~0.95%,微生物量氮对土壤有机氮库的贡献率为3.63%~5.08%。[结论]寒温带针阔混交林主要树种生长季根际土壤微生物量碳氮含量均显著高于非根际,根际效应显著;在生长季末期,针叶树种根际效应相比阔叶树种更为强烈;针叶树种根际土壤微生物量对土壤结构和功能的影响高于阔叶树种。

关键词: 大兴安岭, 土壤微生物量碳氮, 根际土壤, 根际效应, 动态变化

Abstract: [Objective] The rhizosphere plays an vital role for microbial-driven carbon and nitrogen sequestration and nutrient cycling of terrestrial ecosystems. Studies on dynamic of microbial biomass in rhizosphere soil can help us understand the mechanism of utilization and cycle of carbon and nitrogen, and also provide a scientific basis for forest protection and rational management in the study area.[Method] Taking the coniferous and broad-leaved mixed forest as the research object, the rhizosphere and non-rhizosphere soil samples were collected using shaking off method in the forests dominated by the main native tree species in the cold temperate forests of China (Pinus sylvestris var. mongolica, Larix gmelinii, Betula platyphylla and Populus davidiana). The enrichment, the differences and the variations during growing season of microbial biomass carbon and nitrogen in different rhizosphere soils were analyzed to explore the characteristics of soil microbial biomass and its contribution to soil nutrient pool.[Result] The changes of microbial biomass carbon and nitrogen in the rhizosphere soil of the different species were significant among different months. The microbial biomass carbon content in the rhizosphere soil ranged from 114.14 to 451.05 mg·kg-1,the microbial biomass nitrogen content in the rhizosphere soil ranged from 40.38 to 185.00 mg·kg-1. The enrichment rate of microbial biomass carbon in rhizosphere soil was in the order of Pinus sylvestris var. mongolica (87.99%) > Betula platyphylla (78.22%) > Larix gmelinii (73.14%) > Populus davidiana (56.96%). The rank of microbial biomass nitrogen enrichment rate was Populus davidiana (81.50%) > Betula platyphylla (77.63%) > Pinus sylvestris var. mongolica (76.42%) > Larix gmelinii (51.40%). The range of soil microbial biomass carbon-nitrogen ratio was 1.42 to 5.24. The ranges of microbial biomass carbon and nitrogen ratios in the rhizosphere and non-rhizosphere of Pinus sylvestris var. mongolica, Larix gmelinii, Betula platyphylla, and Populus davidiana were 1.42-5.24, 1.57-3.79, 1.67-4.55, 1.55-2.59 and 1.79-3.53, respectively. The average values of soil microbial biomass carbon-nitrogen ratio were 2.64, 2.63, 2.81, 2.11 and 2.36, respectively. The contributions of microbial biomass carbon to the rhizosphere soil organic carbon pool ranged from 0.83% to 0.95%.The contributions of microbial biomass nitrogen to the organic nitrogen pool of rhizosphere soil were between 3.63% and 5.08%.[Conclusion] The content of microbial biomass carbon and nitrogen in the rhizosphere soil of the main cold-temperate mixed forests were significantly higher than those in the non-rhizosphere during the growing season, which indicated that the rhizosphere effect wassignificant. At the end of the growing season, the rhizosphere effects of the coniferous trees were stronger than those of the broad-leaved trees. The conifer species have the greater impact on soil microbial structure and function than the broad-leaved trees.

Key words: Daxing'anling Mountains, soil microbial biomass carbon and nitrogen, rhizosphere soil, rhizosphere effect, dynamic change

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