Temperature controls temporal variation in soil CO₂efflux in a secondary beech forest in Appi Highlands, Japan

Abstract

Forest soil is a huge reserve of carbon in the biosphere. Therefore to understand the carbon cycle in forest ecosystems, it is important to determine the dynamics of soil CO 2 efflux. This study was conducted to describe temporal variations in soil CO 2 efflux and identify the environmental factors that affect it. We measured soil CO 2 efflux continuously in a beech secondary forest in the Appi Highlands in Iwate Prefecture for two years (except when there was snow cover) using four dynamic closed chambers that automatically open after taking measurements. Temporal changes in soil temperature and volumetric soil water content were also measured at a depth of 5 cm. The soil CO 2 efflux ranged from 14 mg CO 2 m -2 h -1 to 2,329 mg CO 2 m -2 h -1 , the peak occurring at the beginning of August. The relationship between soil temperature and soil CO 2 efflux was well represented by an exponential function. Most of temporal variation in soil CO 2 efflux was explained by soil temperature rather than volumetric soil water content. The Q 10 values were 3.7 ± 0.8 and estimated annual carbon emissions were 837 ± 210 g C m -2 year -1 . These results provide a foundation for further development of models for prediction of soil CO 2 efflux driven by environmental factors.

Effects of environmental factors upon variation in soil respiration of a Zoysia japonica grassland, central Japan

“…The studies of soil respiration have been conducted in variable vegetations of Japan, for example, in evergreen needle-leaved forests (e.g., Ohashi et al 2000;Hashimoto et al 2007), in deciduous broad-leaved forests (e.g., Shibata et al 2005;Hashimoto et al 2009), in deciduous needle-leaved forests (Yim et al 2003;Liang et al 2004), in evergreen broad-leaved forests (Kirita 1971;Nakane 1975), in cropland (e.g., Nakadai et al 1996;H ue ta l . 2004) and in grasslands (e.g., Yazaki et al 2004;Wang et al 2009).…”

Carbon balance in a cool–temperate deciduous forest in northern Japan: seasonal and interannual variations, and environmental controls of its annual balance

“…The understory vegetation in the study area was poor, although the forest floor was covered sparsely with evergreen dwarf bamboo (Sasa kurilensis). The soil type was classified as moderately moist brown forest soil, B D(d) (Forest Soil Division 1976) or Andosol, on the basis of the World Reference Base classification Hashimoto et al 2009). The forest is located in a heavy-snow region.…”

Spatial Upscaling of Soil Respiration under a Complex Canopy Structure in an Old‐Growth Deciduous Forest, Central Japan

“…Studies of soil respiration (R s ) have been conducted in many temperate forests and show the temporal variation at both diurnal [1] and seasonal [2][3][4] time scales. The diurnal variation in R s is explained by plant physiology, especially photosynthesis [1], and soil temperature (T s ) [5].…”