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应用生态学报 ›› 2019, Vol. 30 ›› Issue (6): 1911-1918.doi: 10.13287/j.1001-9332.201906.003

• 研究报告 • 上一篇    下一篇

东北5种温带人工林表层土壤碳氮含量的分异

王薪琪, 王传宽*   

  1. 东北林业大学生态研究中心, 哈尔滨 150040
  • 收稿日期:2018-09-14 出版日期:2019-06-15 发布日期:2019-06-15
  • 通讯作者: * E-mail: wangck-cf@nefu.edu.cn
  • 作者简介:王薪琪,女,1991年生,博士研究生. 主要从事森林土壤碳氮循环过程研究. E-mail: xinqi_wang_lucky@163.com
  • 基金资助:
    中央高校基本科研业务费专项资金项目(2572017AA16)、国家“十三五”重点研发计划项目(2016YFD0600201)和教育部长江学者和创新团队发展计划项目(IRT_15R09)资助

Variations in topsoil carbon and nitrogen contents of five temperate plantations in Northeast China.

WANG Xin-qi, WANG Chuan-kuan*   

  1. Center for Ecological Research, Northeast Forestry University, Harbin 150040, China
  • Received:2018-09-14 Online:2019-06-15 Published:2019-06-15
  • Supported by:
    This work was supported by the Fundamental Research Funds for the Central Universities (2572017AA16), the National Key Technology Research and Development Program of China (2016YFD0600201), and the Program for Changjiang Scholars and Innovative Research Team of Ministry of Education of China (IRT_15R09)

摘要: 造林是固碳(C)的有效方法之一,也深刻地影响土壤氮(N)动态,然而不同造林树种对土壤C和N收支的影响及其机制尚不明确.本研究采用同质园试验方法,测定了东北温带水曲柳、胡桃楸、白桦、落叶松和樟子松5个主要造林树种造林后第3年和第11年表层(0~10 cm)土壤有机C(Csoil)、全N含量(Nsoil)的变化,以及植被特性和土壤微生物等相关因子,探究了不同树种造林对土壤C、N的影响及驱动因子.结果表明: 试验期间,5个树种纯林的Csoil、Nsoil均显著降低,Csoil与Nsoil变化量呈显著正相关,并且Csoil减少速率(2.6%·a-1~4.8%·a-1)显著高于Nsoil减少速率(0.8%·a-1~2.8%·a-1).阔叶树种纯林Csoil、Nsoil减少量显著小于针叶树种纯林.树种特征、微生物特性共同解释了Csoil变化率的68.5%、Nsoil变化率的90.9%,Csoil、Nsoil变化率随凋落叶C/N及微生物生物量C/N的增大而减小,但随着细根生物量、微生物生物量C及微生物获取C酶与获取N酶之比的增加而增大;Nsoil变化率还随凋落叶产量及微生物代谢熵的增大而减小.这些温带人工林在造林11年后表层土壤C、N含量显著减少,而树种间的不同变化强度主要是由树种特征和土壤微生物特性的差异引起的.

Abstract: Afforestation is an effective way for carbon (C) sequestration, which also profoundly influences soil nitrogen (N) dynamics in the forest ecosystem. The impacts of tree species on soil C and N budgets and the underlying mechanism remain uncertain. In this study, we used a common garden experiment and measured the soil organic C (Csoil) and total N contents (Nsoil) of the topsoil (0-10 cm) and related vegetative and soil microbial properties in 2007 and 2015 (3 and 11 years after afforestation), respectively. Our aim was to explore the effects of five major tree species (i.e., Fraxinus mandshurica, Juglans mandshurica, Betula platyphylla, Larix gmelinii and Pinus sylvestris var. mongolica) in the temperate forests in Northeast China on soil C and N contents and their dri-vers. The results showed that both Csoil and Nsoil of the five stands decreased as the stand ages increased, the change rates of which were significantly correlated with each other. The rate of change in Csoil(2.6%·a-1-4.8%·a-1) was significantly greater than that in Nsoil(0.8%·a-1-2.8%·a-1). The decrements of the Csoil and Nsoil for the broadleaved stands were significantly lower than those of the coniferous stands. The tree-species traits and microbial properties together explained 68.5% and 90.9% of the variability of the change rates of Csoil and Nsoil, respectively. The change rates of Csoil and Nsoil decreased with the increases in leaf litter C/N and microbial biomass C/N, but increased with the increases of fine root biomass, microbial biomass C, and the ratio of the C-acquisition to the N-acquisition enzyme activity. Additionally, the change rate of Nsoil decreased with the increases of the leaf litter production and the microbial metabolic activity. Our findings indicated that C and N contents in the topsoil of these temperate plantations decreased significantly 11 years after afforestation, while the different change rates mainly resulted from different properties of tree species and soil microbes.