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草业学报 ›› 2019, Vol. 28 ›› Issue (10): 1-11.DOI: 10.11686/cyxb2018724

• 研究论文 • 上一篇    下一篇

放牧对晋北农牧交错带赖草草地生态系统碳交换的影响

邢鹏飞1, 李刚1, 陈晓鹏1, 李德颖2, 王常慧3, 董宽虎1, 赵祥1,*   

  1. 1.山西农业大学动物科技学院, 山西 太谷030801;
    2.北达科他州立大学植物科学系, 美国北达科他 法戈58108;
    3.中国科学院植物研究所植被与环境变化国家重点实验室,北京100093
  • 收稿日期:2018-11-07 修回日期:2019-01-02 出版日期:2019-10-20 发布日期:2019-10-20
  • 通讯作者: E-mail: sxndzhaox@126.com
  • 作者简介:邢鹏飞(1994-),男,山西高平人,在读硕士。E-mail:sxpfxing@163.com
  • 基金资助:
    国家自然科学基金(31572452、31870438),山西省科技创新团队建设项目(2015013001-10)和山西省工程技术研究中心项目(201605D141001)资助

Effects of grazing on carbon exchange in a Leymus secalinus grassland ecosystem in the agro-pastoral ecotone of Northern Shanxi

XING Peng-fei1, LI Gang1, CHEN Xiao-peng1, LI De-ying2, WANG Chang-hui3, DONG Kuan-hu1, ZHAO Xiang1,*   

  1. 1.College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, China;
    2.Department of Plant Science, North Dakota State University, Fargo 58108, United States;
    3.State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China
  • Received:2018-11-07 Revised:2019-01-02 Online:2019-10-20 Published:2019-10-20
  • Contact: E-mail: sxndzhaox@126.com

摘要: 生态系统净碳交换(NEE)是评估碳循环及收支的重要指标,由生态系统总初级生产力(GEP)及生态系统呼吸(ER)共同决定。以晋北农牧交错带赖草草地为研究对象,利用LI-840a静态箱法,通过观测为期2年(2015-2016)围封和放牧管理下NEE、ER和GEP的日动态和季动态,分析其与气温、土壤温度(0~10 cm)、土壤含水量(0~10 cm),以及地上和地下生物量的相关性,旨在说明放牧对农牧交错带赖草草地生态系统碳交换的影响。结果表明:放牧显著降低了赖草草地地上、地下生物量;NEE、ER和GEP的日变化及季节变化特征明显,均呈现单峰型变化,在5、6、9月较低,在7-8月较高;生态系统碳交换的日变化主要受气温影响,而季节变化主要受表层土壤温度影响;同时NEE、ER和GEP与地上、地下生物量也存在极显著相关性;相比围封,放牧明显降低了该草地生物量和生态系统碳交换速率,但未改变日、季变化趋势。说明放牧通过破坏草地植被光合组织,降低了草地生态系统碳交换能力,减弱了草地生态系统碳汇功能。

关键词: 放牧, 赖草草地, 生态系统净碳交换, 生态系统呼吸, 生态系统初级生产力

Abstract: Ecosystem net carbon exchange (NEE) is an important index to evaluate the carbon cycle, and is calculated from total primary productivity (GEP) and ecosystem respiration (ER). The aim of this study was to explore the effects of grazing on carbon exchange in the Leymus secalinus grassland ecosystem in the agro-pastoral ecotone of Northern Shanxi. Using the static chamber technique (LI-840a), we measured the daily and seasonal dynamics of NEE, ER, and GEP in the L. secalinus grassland under grazing during 2015 and 2016, and analyzed the correlation between these indexes and atmospheric temperature, soil temperature, soil moisture content, and aboveground and belowground biomass. The NEE, ER, and GEP showed clear daily and seasonal variations, which were the unimodal type. The values of NEE were lower in May, June, and September, but higher in July and August. The daily dynamics of NEE were mainly controlled by air temperature, while the seasonal changes were mainly controlled by soil temperature. Correlations between aboveground biomass as well as belowground biomass and NEE, ER, and GEP were extremely significant. Compared with fencing, grazing significantly decreased the NEE rate of the ecosystem in this grassland, but it did not affect the daily and seasonal trends in NEE. These results showed that, compared with enclosure, grazing can decrease the carbon exchange capacity and weaken the carbon sink function of a grassland ecosystem by reducing the proportion of photosynthetic matter in grassland vegetation.

Key words: grazing, Leymus secalinus grassland, net ecosystem carbon exchange, ecosystem respiration, gross ecosystem primary productivity