Soil CO2 efflux in a warm-temperature and sub-alpine forest in Jeju, South Korea

Abstract

BackgroundThis study investigated the temporal variation in soil CO2 efflux and its relationship with soil temperature and precipitation in the Quercus glauca and Abies koreana forests in Jeju Island, South Korea, from August 2010 to December 2012. Q. glauca and A. koreana forests are typical vegetation of warm-temperate evergreen forest zone and sub-alpine coniferous forest zone, respectively, in Jeju island.ResultsThe mean soil CO2 efflux of Q. glauca forest was 0.7 g CO2 m−2 h−1 at 14.3 °C and that of A. koreana forest was 0.4 g CO2 m−2 h−1 at 6.8 °C. The cumulative annual soil CO2 efflux of Q. glauca and A. koreana forests was 54.2 and 34.2 t CO2 ha−1, respectively. Total accumulated soil carbon efflux in Q. glauca and A. koreana forests was 29.5 and 18.7 t C ha−1 for 2 years, respectively. The relationship between soil CO2 efflux and soil temperate at 10 cm depth was highly significant in the Q. glauca (r2 = 0.853) and A. koreana forests (r2 = 0.842). Soil temperature was the main controlling factor over CO2 efflux during most of the study period. Also, precipitation may affect soil CO2 efflux that appeared to be an important factor controlling the efflux rate.ConclusionsSoil CO2 efflux was affected by soil temperature as the dominant control and moisture as the limiting factor. The difference of soil CO2 efflux between of Q. glauca and A. koreana forests was induced by soil temperature to altitude and regional precipitation.