Chin J Plan Ecolo ›› 2014, Vol. 38 ›› Issue (4): 396-404.DOI: 10.3724/SP.J.1258.2014.00036

• Research Articles • Previous Articles    

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, and 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 Revised:2013-12-25 Online:2014-04-01 Published:2014-04-08
  • Contact: LI Xiu-Jun

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.