Characteristics of soil respiration in Pinus densiflora stand

Abstract

The purpose of this study is to compare soil CO2 efflux between burned and unburned sites dominated by Pinus densiflora forest in the Samcheok area where a big forest fire broke out along the east coast in 2000 and to measure soil CO2 efflux and environmental factors between March 2011 and February 2012. Soil CO2 efflux was measured with LI-6400 once a month; the soil temperature at 10 cm depth, air temperature, and soil moisture contents were measured in continuum. Soil CO2 efflux showed the maximum value in August 2011 as 417.8 mg CO2 m-2 h-1 (at burned site) and 1175.1 mg CO2 m-2 h-1 (at unburned site), while it showed the minimum value as 41.4 mg CO2 m-2 h-1 (at burned site) in December 2011 and 42.7 mg CO2 m-2 h-1 (at unburned site) in February 2012. The result showed the high correlation between soil CO2 efflux and the seasonal changes in temperature. More specifically, soil temperature showed higher correlation with soil CO2 efflux in the burned site (R2 = 0.932, P < 0.001) and the unburned site (R2 = 0.942, P < 0.001) than the air temperature in the burned site (R2 = 0.668, P < 0.01) and the unburned site (R2 = 0.729, P < 0.001). Q10 values showed higher sensitivity in the unburned site (4.572) than in the burned site (2.408). The total soil CO2 efflux was obtained with the exponential function between soil CO2 efflux and soil temperature during the research period, and it showed 2.5 times higher in the unburned site (35.59 t CO2 ha-2 yr-1, 1 t = 103 kg) than in the burned site (14.69 t CO2 ha-2 yr-1).

Keywords

• LI-6400
• Q10 value
• CO2 efflux
• Q10 value