• Ecology and Resilient Infrastructure
• /
• v.8 no.1
• /
• pp.32-43
• /
• 2021

Multichannel automated chamber systems (MCACs) were developed for the continuous monitoring of soil CO2 efflux in forest ecosystems. The MCACs mainly consisted of four modules: eight soil chambers with lids that automatically open and close, an infrared CO2 analyzer equipped with eight multichannel gas samplers, an electronic controller with time-relay circuits, and a programmable logic datalogger. To examine the stability and reliability of the developed MCACs in the field during all seasons with a high temporal resolution, as well as the effects of temperature and soil water content on soil CO2 efflux rates, we continuously measured the soil CO2 efflux rates and micrometeorological factors at the Nam-san experimental site in a Quercus mongolica forest floor using the MCACs from January to December 2010. The diurnal and seasonal variations in soil CO2 efflux rates markedly followed the patterns of changes in temperature factors. During the entire experimental period, the soil CO2 efflux rates were strongly correlated with the temperature at a soil depth of 5 cm (r2 = 0.92) but were weakly correlated with the soil water content (r2 = 0.27). The annual sensitivity of soil CO2 efflux to temperature (Q10) in this forest ranged from 2.23 to 3.0, which was in agreement with other studies on temperate deciduous forests. The annual mean soil CO2 efflux measured by the MCACs was approximately 11.1 g CO2 m-2 day-1. These results indicate that the MCACs can be used for the continuous long-term measurements of soil CO2 efflux in the field and for simultaneously determining the impacts of micrometeorological factors.

• Journal of Forest and Environmental Science
• /
• v.34 no.3
• /
• pp.253-257
• /
• 2018

Climate models forecast more frequent and a longer period of drought events which may impact forest soil carbon dynamics, thereby altering the soil respiration (SR) rate. We examine the simulated drought effects on soil $CO_2$ effluxes from soil surface partitioning heterotrophic and autotrophic soil respiration sources. Three replicates of drought plots ($6{\times}6m$) were constructed with the same size of three control plots. We examined the relation between $CO_2$ and soil temperature and soil moisture, each being measured at a soil depth of 15 cm. We also compared which factor affected $CO_2$ efflux more under drought conditions. Total SR, autotrophic respiration (AR) and heterotrophic respiration (HR) were positively correlated with soil temperature (p < 0.05), and the relationships were stronger in roof plots than in control plots. Total SR, AR, and HR were negatively correlated only in roof plots, and the only HR showed a significant correlation (p < 0.05, r = -0.59). Soil respiration rates were more influenced by soil temperature than by soil moisture, and this relationship was more evident under drought conditions.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.18 no.3
• /
• pp.120-126
• /
• 2016

This study was carried out to examine the relationships between seasonal variations of soil $CO_2$ efflux rates and soil environmental factors in matured Pinus densiflora and Quercus variabilis stands in the Wola national experimental forests, southern Korea. Soil $CO_2$ efflux rates were measured monthly from March 2015 to February 2016. Mean soil $CO_2$ efflux rates during the study period were significantly higher in the Q. variabilis ($mean{\pm}standard$ error; $2.27{\pm}0.22{\mu}mol\;m^{-2}s^{-1}$) than in the P. densiflora ($1.63{\pm}0.12{\mu}mol\;m^{-2}s^{-1}$) stands. Mean soil water content and pH were also significantly higher in the Q. variabilis ($26.96{\pm}0.93%$, pH 5.19) than in the P. densiflora ($21.32{\pm}0.89%$, pH 4.87) stands, while soil temperature was not significantly different between the P. densiflora ($13.92{\pm}0.67^{\circ}C$) and in the Q. variabilis ($13.52{\pm}0.70^{\circ}C$) stands. $Q_{10}$ values were higher in the Q. variabilis (3.35) than in the P. densiflora (2.72) stands. The results indicate that soil $CO_2$ efflux rates in Q. variabilis stand could be more sensitive by the change of soil temperature compared with P. densiflora stand under a similar site environmental condition.

• Journal of Wetlands Research
• /
• v.20 no.2
• /
• pp.116-123
• /
• 2018

The objective of this study was to examine effects of stand age on soil $CO_2$ efflux in plantation Pinus koraiensis, and to elucidate what extent plant (fine) root and soil microbial biomass contribute to the whole soil $CO_2$ efflux. In three age classes (20-yr-old. 40-yr-old, 70-yr-old) of plantation Pinus koraiensis, in-situ soil respiration, plant fine root biomass and soil microbial biomass were measured from April to November in 2004. Regardless of stand age, soil temperature and soil $CO_2$ efflux increased until July then slowly decreased. Soil respiration was higher in 70-yr-old stand than in 20- and 40-yr stands. Fine root biomass and soil microbial biomass was also higher in 70-yr-old stand. Root exclusion decreased soil respiration in 40-yr stand, but not in 70-yr stand. Soil microbial biomass was higher in 70-yr stand, but there was no monthly variation between July and November. The results suggest that soil respiration may increase as plant stand ages and microbial contribution could play more roles in older stands.

• Journal of Korean Society of Forest Science
• /
• v.105 no.1
• /
• pp.12-18
• /
• 2016

This study was carried out to investigate the change on soil $CO_2$ efflux rates, soil temperature, soil water content and soil pH by thinning intensity treatments (heavy thinning, light thinning, control) of a black pine (Pinus thunbergii Parl.) stand disturbed by pine wilt disease in Wola National Experimental Forests in Jinju, Gyeongnam province. Monthly variations of soil $CO_2$ efflux rates were not significantly different between the thinning and the control treatments (P>0.05). The annual mean soil $CO_2$ efflux rates were $0.58g\;CO_2m^{-2}h^{-1}$ for the light thinning, $0.49g\;CO_2m^{-2}h^{-1}$ for the heavy thinning and $0.45g\;CO_2m^{-2}h^{-1}$ for the control treatments, respectively. There was a significant exponential relation between soil $CO_2$ efflux rates and soil temperature, but no correlation between soil water content or soil pH and soil $CO_2$ efflux rates. The values of $Q_{10}$ were 3.40 for the light thinning, 3.20 for the heavy thinning and 3.06 for the control treatments, respectively. The results indicate that soil $CO_2$ efflux rates in a black pine stand disturbed by pine wilt disease could be affected by thinning treatments.

• Journal of Korean Society of Forest Science
• /
• v.109 no.3
• /
• pp.271-280
• /
• 2020

This study compared soil CO₂ efflux rates after fertilization, in Pinus densiflora and Quercus variabilis stands. Compound fertilizers were applied to the forest floor in March 2016, following a one-year calibration period (from March 2015 to February 2016). In situ soil CO₂ efflux rates were measured every month during the two-year study periods, using an infrared gas analyzer with a closed chamber system. Mean annual soil CO₂ efflux rates were higher following fertilizer application in the P. densiflora and Q. variabilis stands (P. densiflora: 2.180 μmol m^-2 s^-1; Q. variabilis: 1.977 μmol m^-2 s^-1) as compared with the rates measured during the calibration period (P. densiflora: 1.620 μmol m^-2 s^-1; Q. variabilis: 1.557 μmol m^-2 s^-1). The mean annual soil CO₂ efflux rates in the unfertilized treatments of both stands were not significantly different between the two-year study periods. The Q₁₀ values of fertilized treatments in Q. variabilis stands were higher in the fertilization period (3.41) than in the calibration period (3.14), whereas the Q₁₀ values in P. densiflora stands did not change between the fertilization and calibration periods. The Q₁₀ values of unfertilized treatments in the Q. variabilis stands were lower during the 2016-2017 period (3.69), than in the 2015-2016 period (3.85), whereas the Q₁₀ values in P. densiflora stands were higher during the 2016-2017 period (3.65), than in the 2015-2016 period (3.15). These results indicate that the increase in soil CO₂ efflux rates in P. densiflora stands could be more sensitive to fertilization compared with the rates in Q. variabilis stands.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.5 no.2
• /
• pp.94-100
• /
• 2003

Soil $CO_2$ emission is one of the primary components in carbon balance of terrestrial ecosystems. To accurately assess their net ecosystem exchange of $CO_2$ and net primary production, measurement of soil $CO_2$ efflux is required along with that of canopy $CO_2$ flux. In this paper, soil $CO_2$ flux measurement technique using closed dynamic chamber systems is briefly reviewed. Preliminary results on soil $CO_2$ exchange and inter-comparison of different measurement systems currently used in Korean regional network of tower flux measurement sites (KoFlux) are also reported.

• Proceedings of the Korean Society of Environment and Ecology Conference
• /
• autumn
• /
• pp.31-34
• /
• 2004

• Korean Journal of Environment and Ecology
• /
• v.32 no.6
• /
• pp.676-685
• /
• 2018

This study is to compare carbon budget between serpentine sites and non-serpentine sites dominated by Pinus densiflora forest in the Andong serpentine area where has high values of magnesium and low values of calcium, and are usually deficient in nitrogen and phosphorus, but rich in heavy metals such as nickel, chrome, cobalt, etc. and to measure soil $CO_2$ efflux and environmental factors between January 2017 and December 2017. Soil $CO_2$ efflux was measured with LI-6400 once a month; the soil temperature at 10 cm depth, air temperature, soil moisture contents, and solar radiation were measured in continuum. Soil $CO_2$ efflux in the serpentine area and non-serpentine were $151.71{\pm}75.09g\;CO_2{\cdot}m^{-2}month^{-1}$(42.48 ~ 262.61 g $CO_2{\cdot}m^{-2}month^{-1}$) and $165.09{\pm}118.96g\;CO_2{\cdot}m^{-2}month^{-1}$(20.94 ~ 449.24 g $CO_2{\cdot}m^{-2}month^{-1}$), respectively. Carbon storage in the serpentine area and non-serpentine area were 91.90, $222.85ton{\cdot}ha^{-1}$, respectively. Carbon absorption in the serpentine area and non-serpentine area were 7.99, $17.41ton{\cdot}ha^{-1}yr^{-1}$, respectively. Carbon budget in the serpentine area and non-serpentine area were absorbs 5.3, $14.49ton{\cdot}Cha^{-1}yr^{-1}$, respectively.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.11 no.4
• /
• pp.247-251
• /
• 2009

To estimate the effect of rainfall on soil respiration, soil $CO_2$ efflux was measured with a manipulation of rainfall interception at a broad-leaved deciduous forest in western Japan from 20 February to 19 November 2001. The diurnal patterns of soil respiration observed at the intercepted subplot ($F_c$) were quite similar to those of soil temperature at 0.2 m depth with a maximum around midnight and a minimum from noon to early afternoon. Such diurnal patterns have not been observed in the previous studies at the same study site under natural conditions (which manifested no clear diurnal variations). Furthermore, the magnitudes of $F_c$ showed substantial differences (e.g., ~50% reduction under water-limited conditions) compared to those of the potential soil respiration under natural conditions ($F_{cal}$). These findings demonstrate that rainfall events not only affected the magnitude of soil $CO_2$ efflux but also modified the vertical structure of soil temperature, thereby altering diurnal patterns of soil respiration.