Annual Variation of Soil CO2 Efflux in a Broadleaved Deciduous Forest of the Geumsan (Mt.) Long-Term Ecological Research Site

Abstract

Soil respiration in forest ecosystems play an important role in global carbon cycle. This study was carried out to determine the annual variation of soil CO2 efflux for 4 years in a broadleaved deciduous forest of the Geumsan (Mt.) Long-Term Ecological Research (GLTER) site in Southern Korea. The soil CO2 efflux in the GLTER site showed annual variations with the fluctuations of annual mean soil temperature, but not with those of soil water content. The annual mean soil CO2 efflux except for winter season was 0.32 g CO2 m−2 h−1 for 2008, 0.40 g CO2 m−2 h−1 for 2009, 0.41 g CO2 m−2 h−1 for 2007, and 0.54 g CO2 m−2 h−1 for 2010. The lowest soil CO2 effluxin 2008 was associated with the lowest soil temperature (12.0oC) in comparison with those of other years (13.0-13.5oC). The exponential relationships between monthly soil CO2 efflux and the corresponding soil temperature at the soil depth of 20 cm were significant (R2 = 0.31-0.75, P < 0.05). The results indicate that the annual variation of soil CO2 efflux was attributed to the variations of soil temperature rather than soil water content in the GLTER site.