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中国沙漠 ›› 2022, Vol. 42 ›› Issue (4): 219-228.DOI: 10.7522/j.issn.1000-694X.2022.00013

• • 上一篇    

疏勒河源冻土区高寒草甸土壤碳氮含量特征

贾映兰1,2(), 吴明辉1,2, 魏培洁1,2, 赵建中4, 高雅月5, 陈生云1,3,5()   

  1. 1.中国科学院西北生态环境资源研究院 冰冻圈科学国家重点实验室/疏勒河源冰冻圈与生态环境综合监测研究站,甘肃 兰州 730000
    2.中国科学院大学,北京 100049
    3.青海师范大学 高原科学与可持续发展研究院/地理科学学院,青海 西宁 810008
    4.青海农牧科技职业学院,青海 西宁 812100
    5.祁连山国家公园国家长期科研基地,青海 西宁 810000
  • 收稿日期:2021-11-17 修回日期:2022-01-19 出版日期:2022-07-20 发布日期:2022-08-29
  • 通讯作者: 陈生云
  • 作者简介:陈生云(E-mail: sychen@lzb.ac.cn
    贾映兰(1996—),女,甘肃陇西人,硕士研究生,研究方向为冻土碳氮循环。E-mail: yinglanj@163.com
  • 基金资助:
    国家自然科学基金项目(41871064);青海省重点研发与转化计划项目(2020-SF-146);青海省“高端创新人才千人计划”高层次人才项目

Characteristics of soil carbon and nitrogen contents in permafrost region of the Shule River Headwaters

Yinglan Jia1,2(), Minghui Wu1,2, Peijie Wei1,2, Jianzhong Zhao4, Yayue Gao5, Shengyun Chen1,3,5()   

  1. 1.State Key Laboratory of Cryospheric Science / Cryosphere and Eco-Environment Research Station of Shule River Headwaters,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China
    2.University of Chinese Academy of Sciences,Beijing 100049,China
    3.Academy of Plateau Science and Sustainability /School of Geographical Sciences,Qinghai Normal University,Xining 810008,China
    4.Qinghai Agri -animal Husbandry Vocational College,Xining 812100,China
    5.Long-term National Scientific Research Base of the Qilian Mountain National Park,Xining 810000,China
  • Received:2021-11-17 Revised:2022-01-19 Online:2022-07-20 Published:2022-08-29
  • Contact: Shengyun Chen

摘要:

土壤碳氮是高寒植被响应多年冻土区生态环境变化的重要营养和能源物质,但对其调查仍以生长季的单次采样为主,缺乏对其他季节的研究,这对于准确把握多年冻土区土壤碳氮含量及储量评估存在明显局限性。为此,本研究以青藏高原东北缘祁连山西段疏勒河源多年冻土区高寒草甸为对象,对0—50 cm土层土壤有机碳(Soil Organic Carbon, SOC)、全氮(Total Nitrogen, TN)含量及其比值(C/N)的剖面分布和季节变化及其影响因素进行分析。结果表明:(1)SOC、TN剖面分布规律一致,0—10 cm土层均显著高于10—50 cm各层(P<0.05),0—50 cm深度仅秋季逐渐下降,而春夏冬季0—30 cm递减。(2)SOC、TN含量存在季节变化,SOC表现为夏季>冬季>春季>秋季,TN表现为春秋冬季含量一致,夏季略低。(3)C/N季节变化显著,夏季显著最高,秋季显著最低(P<0.05)。(4)土壤含水量和生物量是影响SOC、TN及C/N剖面分布和季节变化的关键因素。(5)夏季土壤碳氮密度均高于全年平均。可见,仅单一节点(生长季为主)调查以表征全年土壤碳氮储量存在高估趋势。

关键词: 多年冻土区, 高寒草甸, 土壤碳氮, 剖面变化, 季节特征

Abstract:

Soil carbon and nitrogen are important nutrient and energy substances for alpine vegetation to respond to the changes of ecological environment in permafrost regions. However, their surveys are still based on single-pass sampling during the growing season, and there is a lack of researches on seasonal changes, which is very important but exists obvious limitation for accurately grasping contents and estimating storages of soil carbon and nitrogen in permafrost area. Thus, in the study, the alpine meadow, located at the permafrost regions of Shule River headwaters in the western part of the Qilian Mountains and the northeast margin of the Qinghai-Tibet Plateau, was selected as the study area. The vertical (0-50 cm profile) and seasonal variations of soil organic carbon (SOC), total nitrogen (TN) contents and carbon to nitrogen ratio (C/N), as well as their influencing factors were analyzed. The results showed that: (1) The profile distribution of SOC and TN are consistent as, SOC and TN in the 0-10 cm soil layer were significantly higher than those in the 10-50 cm (P<0.05). However, the SOC and TN decreased gradually from 0 to 50 cm only in autumn, while 0-30 cm in spring, summer and winter; (2) Seasonal changes were found in SOC and TN contents, and SOC showed summer > winter > spring > autumn, while TN was consistent in spring, autumn and winter, but slightly lower in summer; (3) The seasonal variation of C/N was remarkable (P<0.05), which highest in summer and lowest in autumn; 4) Soil moisture content and vegetation biomass were key factors for vertical and seasonal changes in the SOC content, TN content and C/N; (5) The soil carbon and nitrogen density in summer were higher than the annual average. It can be seen that only the survey of a single node (mainly in the growing season) indicates that there is an overvalued trend of the annual soil carbon and nitrogen storage.

Key words: permafrost regions, alpine meadow, soil carbon and nitrogen, vertical change, seasonal pattern

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