Soil-surface CO2 fluxes in a Deyeuxia angustifolia wetland in Sanjiang Plain, China

In many temperate-zone ecosystems, seasonal changes in environmental and biological factors influence the dynamics and magnitude of surface–atmosphere exchange. Research was conducted between July and October 2001 to measure growing season surface-layer fluxes of CO2 in a Deyeuxia angustifolia dominated wetland on the Sanjiang Plain in northeastern China. Seasonal fluctuation and daily change in soil-surface CO2 fluxes were measured as well as the edaphic factors controlling CO2 fluxes. Soil-surface CO2 fluxes were measured with a closed-chamber system. The results revealed that there were both seasonal fluctuations and daily change in CO2 fluxes. The ranges of measured soil-surface CO2 flux were 0.208 – 1.265 g CO2m−2h−1. Soil-surface CO2 fluxes averaged 0.620 g CO2 m−2h−1. An analysis of several edaphic factors including soil temperature and soil moisture of the D. angustifolia wetland showed that there was a significant relationship between flux and temperature (R2 = 0.77).