中国地理科学 ›› 2014, Vol. 0 ›› Issue (3): 287-296.doi: 10.1007/s11769-014-0682-5

• 论文 • 上一篇    下一篇

Diurnal and Seasonal Dynamics of Soil Respiration at Temperate Leymus Chinensis Meadow Steppes in Western Songnen Plain, China

WANG Ming1,2, LIU Xingtu1, ZHANG Jitao1, LI Xiujun1, WANG Guodong1,2, LI Xiaoyu1, LU Xinrui1   

  1. 1. Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • 收稿日期:2013-08-30 修回日期:2013-11-27 出版日期:2014-03-27 发布日期:2014-04-30
  • 通讯作者: LI Xiujun. E-mail: lixiujun@neigae.ac.cn E-mail:lixiujun@neigae.ac.cn
  • 基金资助:

    Under the auspices of Special Fund for Agro-scientific Research in Public Interest, China (No. 201303095-8), National Natural Science Foundation of China (No. 31100403, 41101207), National Basic Research Program of China (No. 2013CB430401), Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences

Diurnal and Seasonal Dynamics of Soil Respiration at Temperate Leymus Chinensis Meadow Steppes in Western Songnen Plain, China

WANG Ming1,2, LIU Xingtu1, ZHANG Jitao1, LI Xiujun1, WANG Guodong1,2, LI Xiaoyu1, LU Xinrui1   

  1. 1. Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2013-08-30 Revised:2013-11-27 Online:2014-03-27 Published:2014-04-30
  • Contact: LI Xiujun. E-mail: lixiujun@neigae.ac.cn E-mail:lixiujun@neigae.ac.cn
  • Supported by:

    Under the auspices of Special Fund for Agro-scientific Research in Public Interest, China (No. 201303095-8), National Natural Science Foundation of China (No. 31100403, 41101207), National Basic Research Program of China (No. 2013CB430401), Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences

摘要:

To evaluate the diurnal and seasonal variations in soil respiration (Rs) and understand the controlling factors, we measured carbon dioxide (CO2) fluxes and their environmental variables using a LI-6400 soil CO2 flux system at a temperate Leymus chinensis meadow steppe in the western Songnen Plain of China in the growing season (May-October) in 2011 and 2012. The diurnal patterns of soil respiration could be expressed as single peak curves, reaching to the maximum at 11:00-15:00 and falling to the minimum at 21:00-23:00 (or before dawn). The time-window between 7:00 and 9:00 could be used as the optimal measuring time to represent the daily mean soil CO2 efflux. In the growing season, the daily value of soil CO2 efflux was moderate in late spring (1.06-2.51 μmol/(m2·s) in May), increased sharply and presented a peak in summer (2.95-3.94 μmol/(m2·s) in July), and then decreased in autumn (0.74-0.97 μmol/(m2·s) in October). Soil temperature (Ts) exerted dominant control on the diurnal and seasonal variations of soil respiration. The temperature sensitivity of soil respiration (Q10) exhibited a large seasonal variation, ranging from 1.35 to 3.32, and decreased with an increasing soil temperature. Rs gradually increased with increasing soil water content (Ws) and tended to decrease when Ws exceeded the optimum water content (27%) of Rs. The Ts and Ws had a confounding effect on Rs, and the two-variable equations could account for 72% of the variation in soil respiration (p < 0.01).

关键词: soil respiration, Leymus chinensis, temperature sensitivity of soil respiration (Q10), soil temperature, soil water content

Abstract:

To evaluate the diurnal and seasonal variations in soil respiration (Rs) and understand the controlling factors, we measured carbon dioxide (CO2) fluxes and their environmental variables using a LI-6400 soil CO2 flux system at a temperate Leymus chinensis meadow steppe in the western Songnen Plain of China in the growing season (May-October) in 2011 and 2012. The diurnal patterns of soil respiration could be expressed as single peak curves, reaching to the maximum at 11:00-15:00 and falling to the minimum at 21:00-23:00 (or before dawn). The time-window between 7:00 and 9:00 could be used as the optimal measuring time to represent the daily mean soil CO2 efflux. In the growing season, the daily value of soil CO2 efflux was moderate in late spring (1.06-2.51 μmol/(m2·s) in May), increased sharply and presented a peak in summer (2.95-3.94 μmol/(m2·s) in July), and then decreased in autumn (0.74-0.97 μmol/(m2·s) in October). Soil temperature (Ts) exerted dominant control on the diurnal and seasonal variations of soil respiration. The temperature sensitivity of soil respiration (Q10) exhibited a large seasonal variation, ranging from 1.35 to 3.32, and decreased with an increasing soil temperature. Rs gradually increased with increasing soil water content (Ws) and tended to decrease when Ws exceeded the optimum water content (27%) of Rs. The Ts and Ws had a confounding effect on Rs, and the two-variable equations could account for 72% of the variation in soil respiration (p < 0.01).

Key words: soil respiration, Leymus chinensis, temperature sensitivity of soil respiration (Q10), soil temperature, soil water content