植物生态学报 ›› 2014, Vol. 38 ›› Issue (4): 396-404.DOI: 10.3724/SP.J.1258.2014.00036

• 研究论文 • 上一篇    

松嫩平原西部草甸草原5种典型植物群落土壤呼吸的时空动态

王铭1,2(), 刘兴土1, 张继涛1, 李秀军1,**(), 王国栋1,2, 鲁新蕊1, 李晓宇1   

  1. 1中国科学院东北地理与农业生态研究所中国科学院湿地生态与环境重点实验室, 长春 130102
    2中国科学院大学, 北京 100049
  • 收稿日期:2013-10-28 接受日期:2013-12-02 出版日期:2014-10-28 发布日期:2014-04-08
  • 通讯作者: 李秀军
  • 作者简介:**(E-mail:lixiujun@neigae.ac.cn)
    * E-mail:wangming@neigae.ac.cn
  • 基金资助:
    国家重点基础研究发展计划项目(2012-CB956103);公益性行业农业科研专项(201303-095-8);国家自然科学青年基金(31100403);国家自然科学青年基金(4110- 1207)

Spatio-temporal variations of soil respiration in five typical plant communities in the meadow steppe of the western Songnen Plain, China

WANG Ming1,2(), LIU Xing-Tu1, ZHANG Ji-Tao1, LI Xiu-Jun1,**(), WANG Guo-Dong1,2, LU Xin-Rui1, LI Xiao-Yu1   

  1. 1Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2013-10-28 Accepted:2013-12-02 Online:2014-10-28 Published:2014-04-08
  • Contact: LI Xiu-Jun

摘要:

土壤呼吸是陆地生态系统碳循环的重要组分, 由于受到生物因子与非生物因子的共同作用, 土壤碳排放量在时间和空间尺度上都具有一定的变异性。为弄清松嫩平原西部草甸草原植物群落土壤呼吸作用的时空动态变化及其影响因子, 以典型植被碱蓬(Suaeda glauca)、虎尾草(Chloris virgata)、碱茅(Puccinellia distans)、芦苇(Phragmites australis)、羊草(Leymus chinensis)群落为研究对象, 采用LI-6400土壤呼吸测定系统对该生态系统2011-2012年植物生长季内土壤呼吸作用进行了监测。结果表明: 土壤温度可以解释土壤呼吸作用变异的53%-82%, 是影响该生态系统土壤碳排放时间变异的主要因素。土壤水分并未对土壤呼吸作用时间变异产生明显的影响。不同植物群落的土壤呼吸的温度敏感性(Q10)有所差异, Q10为2.0-6.7。生长季内, 5种植物群落的土壤累积碳排放量的平均值为316.6 g C·m-2。生长季内土壤碳累积排放量与植被地上生物量、土壤有机碳含量、平均土壤温度显著正相关, 与平均土壤含水量、pH值、土壤电导率及交换性钠百分比呈负相关关系。土壤的微气候、植被的地上生物量及土壤性质的差异是土壤碳排放空间变异的主要影响因素。

关键词: 草甸草原, 土壤呼吸, 土壤温度, 土壤含水量, 时空格局

Abstract:

Aims Soil respiration plays a critical role in the process of carbon cycling in terrestrial ecosystems, and it often shows spatio-temporal variations in response to diverse abiotic and biotic factors. Our objective was to examine the seasonal and spatial variations of soil respiration under five typical plant communities in the meadow steppe of western Songnen Plain.
Methods Using a LI-6400 soil CO2 flux system, we investigated soil respiration and environmental factors under five vegetation types (Suaeda glauca, Chloris virgata, Puccinellia distans, Phragmites australis and Leymus chinensis) in the meadow steppe of Songnen Plain during the growing seasons of 2011 and 2012.
Important findings Soil temperature was the dominant controlling factor of soil respiration, which explained approximately 64% of the changes in soil CO2 effluxes. Soil water content was not the limiting factor of the seasonal variations in soil respiration. The sensitivities of soil respiration to temperature (Q10) ranged from 2.0 to 6.7, showing significant differences among vegetation types. The cumulative CO2 emission averaged 316.6 g C·m-2 during the growing season. The magnitude of soil CO2 emission during the growing season was positively correlated with aboveground plant biomass, soil organic carbon content, and mean soil water content, and negatively linked to mean soil temperature, pH, electrical conductivity, and percentage of exchangeable sodium. The spatial variations of soil CO2 emission were mainly caused by changes in soil microclimate, plant biomass, and soil properties.

Key words: meadow steppe, soil respiration, soil temperature, soil water content, spatial and temporal pattern