干旱区研究 ›› 2021, Vol. 38 ›› Issue (5): 1346-1354.doi: 10.13866/j.azr.2021.05.16

• 土壤资源 • 上一篇    下一篇

祁连山南坡不同土地利用方式下土壤碳氮含量及通径分析

刁二龙1,2,3(),曹广超2,3(),曹生奎1,2,3,袁杰1,2,3,虞敏1,2,3,陈真1,2,3,张卓,童珊1,2,3,赵美亮1,2,3   

  1. 1. 青海师范大学 地理科学学院,青海 西宁 810008
    2. 青藏高原地表过程与生态保育教育部重点实验室,青海 西宁 810008
    3. 青海省自然地理与环境过程重点实验室,青海 西宁 810008
  • 收稿日期:2021-03-25 修回日期:2021-06-23 出版日期:2021-09-15 发布日期:2021-09-24
  • 通讯作者: 曹广超
  • 作者简介:刁二龙(1991-),男,博士研究生,研究方向为环境地表过程与生态响应. E-mail: 1530875132@qq.com
  • 基金资助:
    国家重点研发计划项目(2017YFC0404304);青海省自然科学基金项目(2018-ZJ-903);青海省“高端创新人才千人计划”(青人才字[2016]32号);祁连山国家公园青海研究中心开放课题(GKQ2019-1)

Soil carbon and nitrogen content and path analysis under different land use patterns on the southern slope of Qilian Mountains

DIAO Erlong1,2,3(),CAO Guangchao2,3(),CAO Shengkui1,2,3,YUAN Jie1,2,3,YU Min1,2,3,CHEN Zhen1,2,3,ZHANG Zhuo,TONG Shan1,2,3,ZHAO Meiliang1,2,3   

  1. 1. School of Geographical Science of Qinghai Normal University, Xining 810008, Qinghai, China
    2. MOE Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation, Xining 810008, Qinghai, China
    3. Qinghai Province Key Laboratory of Physical Geography and Environmental Process, Xining 810008, Qinghai, China
  • Received:2021-03-25 Revised:2021-06-23 Online:2021-09-15 Published:2021-09-24
  • Contact: Guangchao CAO

摘要:

以祁连山南坡4种土地利用类型为研究对象,采用野外采样、实验室分析与单因素方差分析方法对不同土地利用方式下浅层(0~20 cm)和深层(20~50 cm)土壤TC(全碳)、TN(全氮)含量及差异显著性进行分析,使用通径分析方法揭示环境因子对土壤TC、TN的直接和间接作用效应。结果表明:(1) 环境因子间相互作用,共同影响土壤碳氮含量。直接作用效应:土壤碳氮相互作用显著,pH对土壤碳氮含量直接作用较小。间接作用效应:土壤含水量(SWC)主要通过TN对浅层土壤TC含量起间接正效应,而pH通过TN对深层土壤TC含量起间接负效应。温度(T)主要通过降水(P)对浅层土壤TN含量起间接负效应,而容重(Pb)通过TC对深层土壤TN含量起间接负效应。(2) 土壤碳氮含量具有明显的“表聚作用”。随土层深度的增加,土壤碳氮含量呈减少趋势。林地土壤碳氮含量最高,显著高于草地和耕地(P<0.05),但与灌丛差异不显著(P>0.05),研究区土壤氮含量较高,可为研究区植被生长提供较为充足的氮素养分元素。(3) 土壤碳氮含量受自然环境和人类活动综合影响。

关键词: 祁连山南坡, 土地利用方式, 土壤全碳, 土壤全氮, 通径分析

Abstract:

Taking the soils under four different land use types on the southern slope of Qilian Mountain as the research object, we used field sampling, laboratory analysis, and one-way ANOVA to analyze the TC and TN contents in surface (0-20 cm) and deep (20-50 cm) layers of soil. A path analysis method was used to reveal the direct and indirect effects of environmental factors on soil TC and TN. The results were as follows. (1) As a direct effect, the soil carbon and nitrogen interaction was significant, but pH had little direct effect on soil carbon and nitrogen content. As an indirect effect, soil water content had a positive effect on TC content in surface soil mainly through TN, whereas pH had an indirect negative effect on TC content in deep soil mainly through TN. Temperature had an indirect negative effect on soil TN content mainly through precipitation, whereas bulk density had an indirect negative effect on soil TN content mainly through TC. (2) Soil carbon and nitrogen content showed obvious “surface polymerization.” The content of soil carbon and nitrogen decreased as soil depth increased. The carbon and nitrogen content of forest soil was the highest; these contents were significantly higher than those found in soil from grassland and cultivated land(P<0.05) but were not significantly different from the contents in shrub soil(P<0.05). The soil nitrogen content in the study area was higher than the national soil nitrogen content grading standard, which could provide sufficient nitrogen nutrient elements for the growth of vegetation in this area. (3) Soil carbon and nitrogen content was affected by the natural environment and human activities. Although this study focused on the effects of natural environmental factors on soil carbon and nitrogen content, the effects of human activities on these contents were not considered; thus, the impact of human activities should be further analyzed future research.

Key words: the southern slope of Qilian Mountain, land use type, soil total carbon, soil total nitrogen, path analysis