Relationship of root biomass and soil respiration in a stand of deciduous broadleaved trees—a case study in a maple tree

이재석 한국생태학회 2018 Journal of Ecology and Environment Vol.42 No.4

Background: In ecosystem carbon cycle studies, distinguishing between CO2 emitted by roots and by microbes remains very difficult because it is mixed before being released into the atmosphere. Currently, no method for quantifying root and microbial respiration is effective. Therefore, this study investigated the relationship between soil respiration and underground root biomass at varying distances from the tree and tested possibilities for measuring root and microbial respiration. Methods: Soil respiration was measured by the closed chamber method, in which acrylic collars were placed at regular intervals from the tree base. Measurements were made irregularly during one season, including high temperatures in summer and low temperatures in autumn; the soil’s temperature and moisture content were also collected. After measurements, roots of each plot were collected, and their dry matter biomass measured to analyze relationships between root biomass and soil respiration. Results: Apart from root biomass, which affects soil’s temperature and moisture, no other factors affecting soil respiration showed significant differences between measuring points. At each point, soil respiration showed clear seasonal variations and high exponential correlation with increasing soil temperatures. The root biomass decreased exponentially with increasing distance from the tree. The rate of soil respiration was also highly correlated exponentially with root biomass. Based on these results, the average rate of root respiration in the soil was estimated to be 34.4% (26.6~43.1%). Conclusions: In this study, attempts were made to differentiate the root respiration rate by analyzing the distribution of root biomass and resulting changes in soil respiration. As distance from the tree increased, root biomass and soil respiration values were shown to strongly decrease exponentially. Root biomass increased logarithmically with increases in soil respiration. In addition, soil respiration and underground root biomass were logarithmically related; the calculated root-breathing rate was around 44%. This study method is applicable for determining root and microbial respiration in forest ecosystem carbon cycle research. However, more data should be collected on the distribution of root biomass and the correlated soil respiration.

토양호흡 간이 측정기를 이용한 광미와 산림토양의 질적 평가

김성철 ( S. C. Kim ),김유범 ( Y. B. Kim ),오세진 ( S. J. Oh ),이상필 ( S. P. Lee ),주진호 ( J. H. Joo ),양재의 ( J. E. Yang ) 강원대학교 농업생명과학연구원(구 농업과학연구소) 2011 강원 농업생명환경연구 Vol.23 No.4

Soil respiration is a key component of the global carbon cycle but limited research has been conducted to examine the biological parameters of soil quality. Thus, The objectives of this research were to develop a simple, easy, and cost-effective standard kit to assess soil respiration and to estimate correlation between soil properties and soil respiration. For the standard kit to assess soil respiration, an ideal reactive substance was selected based on pH range. Depending on color development of the gel containing the reactive substance, soil respiration state was rated representing:<45 mg/kg/day (dark green), 45-70 mg/kg/day (green), 70-140 mg/kg/day (yellowish green), 140-300 mg/kg/day (yellow),>300 mg/kg/day (orange). Soil samples collected from two different sites (tailing and forest soils) were investigated for chemical (pH1:1, EC1:1, total organic C, and Total nitrogen, Melich 3 extractable P, and Melich 3 extratable K) and biological (Microbial C, Microbial N, Potentially mineralizable N) properties and clustered by the standard kit for soil respiration. While soil respiration level of tailings measured with kit generally ranked Group I and II representing low or moderately low soil activity, forest soils were ranked Group III and IV representing medium and ideal soil activity. Among other physicochemical properties of soil, total organic carbon (ρ=0.81) for tailing and EC1:1 (ρ=0.87) for forest soil were the most correlated parameters with soil respiration. Within biological properties, Microbial mass C (ρ=0.86 for tailing and ρ=0.80 for forest soil) showed the most correlated parameter with soil respiration. Overall, soil respiration assessment kit might have a potential to be used as a tool for quality assessment of soil biological indicators.

Relationship of root biomass and soil respiration in a stand of deciduous broadleaved trees-a case study in a maple tree

Lee, Jae-Seok The Ecological Society of Korea 2018 Journal of Ecology and Environment Vol.42 No.4

Background: In ecosystem carbon cycle studies, distinguishing between $CO_2$ emitted by roots and by microbes remains very difficult because it is mixed before being released into the atmosphere. Currently, no method for quantifying root and microbial respiration is effective. Therefore, this study investigated the relationship between soil respiration and underground root biomass at varying distances from the tree and tested possibilities for measuring root and microbial respiration. Methods: Soil respiration was measured by the closed chamber method, in which acrylic collars were placed at regular intervals from the tree base. Measurements were made irregularly during one season, including high temperatures in summer and low temperatures in autumn; the soil's temperature and moisture content were also collected. After measurements, roots of each plot were collected, and their dry matter biomass measured to analyze relationships between root biomass and soil respiration. Results: Apart from root biomass, which affects soil's temperature and moisture, no other factors affecting soil respiration showed significant differences between measuring points. At each point, soil respiration showed clear seasonal variations and high exponential correlation with increasing soil temperatures. The root biomass decreased exponentially with increasing distance from the tree. The rate of soil respiration was also highly correlated exponentially with root biomass. Based on these results, the average rate of root respiration in the soil was estimated to be 34.4% (26.6~43.1%). Conclusions: In this study, attempts were made to differentiate the root respiration rate by analyzing the distribution of root biomass and resulting changes in soil respiration. As distance from the tree increased, root biomass and soil respiration values were shown to strongly decrease exponentially. Root biomass increased logarithmically with increases in soil respiration. In addition, soil respiration and underground root biomass were logarithmically related; the calculated root-breathing rate was around 44%. This study method is applicable for determining root and microbial respiration in forest ecosystem carbon cycle research. However, more data should be collected on the distribution of root biomass and the correlated soil respiration.

Effect of precipitation on soil respiration in a temperate broad-leaved forest

Jeong, Seok-Hee,Eom, Ji-Young,Park, Joo-Yeon,Chun, Jung-Hwa,Lee, Jae-Seok The Ecological Society of Korea 2018 Journal of Ecology and Environment Vol.42 No.6

Background: For understanding and evaluating a more realistic and accurate assessment of ecosystem carbon balance related with environmental change or difference, it is necessary to analyze the various interrelationships between soil respiration and environmental factors. However, the soil temperature is mainly used for gap filling and estimation of soil respiration (Rs) under environmental change. Under the fact that changes in precipitation patterns due to climate change are expected, the effects of soil moisture content (SMC) on soil respiration have not been well studied relative to soil temperature. In this study, we attempt to analyze relationship between precipitation and soil respiration in temperate deciduous broad-leaved forest for 2 years in Gwangneung. Results: The average soil temperature (Ts) measured at a depth of 5 cm during the full study period was $12.0^{\circ}C$. The minimum value for monthly Ts was $-0.4^{\circ}C$ in February 2015 and $2.0^{\circ}C$ in January 2016. The maximum monthly Ts was $23.6^{\circ}C$ in August in both years. In 2015, annual precipitation was 823.4 mm and it was 1003.8 mm in 2016. The amount of precipitation increased by 21.9% in 2016 compared to 2015, but in 2015, it rained for 8 days more than in 2016. In 2015, the pattern of low precipitation was continuously shown, and there was a long dry period as well as a period of concentrated precipitation in 2016. 473.7 mm of precipitation, which accounted for about 51.8% of the precipitation during study period, was concentrated during summer (June to August) in 2016. The maximum values of daily Rs in both years were observed on the day when precipitation of 20 mm or more. From this, the maximum Rs value in 2015 was $784.3mg\;CO_2\;m^{-2}\;h^{-1}$ in July when 26.8 mm of daily precipitation was measured. The maximum was $913.6mg\;CO_2\;m^{-2}\;h^{-1}$ in August in 2016, when 23.8 mm of daily precipitation was measured. Rs on a rainy day was 1.5~1.6 times higher than it without precipitation. Consequently, the annual Rs in 2016 was about 12% higher than it was in 2015. It was shown a result of a 14% increase in summer precipitation from 2015. Conclusions: In this study, it was concluded that the precipitation pattern has a great effect on soil respiration. We confirmed that short-term but intense precipitation suppressed soil respiration due to a rapid increase in soil moisture, while sustained and adequate precipitation activated Rs. In especially, it is very important role on Rs in potential activating period such as summer high temperature season. Therefore, the accuracy of the calculated values by functional equation can be improved by considering the precipitation in addition to the soil temperature applied as the main factor for long-term prediction of soil respiration. In addition to this, we believe that the accuracy can be further improved by introducing an estimation equation based on seasonal temperature and soil moisture.

강우 이벤트가 태화산 잣나무 식재림의 각 발생원별 CO2 발생량에 미치는 영향

서상욱 ( Sang Uk Suh ),박성애 ( Sung Ae Park ),심규영 ( Kyu Young Shim ),양병국 ( Byeong Gug Yang ),최은정 ( Eun Jung Choi ),이재석 ( Jae Seok Lee ),김태규 ( Tae Kyu Kim ) 한국환경생물학회 2014 환경생물 : 환경생물학회지 Vol.32 No.4

This study was conducted to find out the soil CO2 emission characteristic due to rain fall pattern and intensity changes. Using Automatic Opening and Closing Chambers (AOCCs), we have measured annual soil respiration changes in Pinus koraiensis plantation at Seoul NationalUniversity experimental forest in Mt. Taehwa. In addition, we have monitored heterotrophic respiration at trenching sites (4×6 m). Based on the one year data of soil respiration and heterotrophicrespiration, we observed that 24% of soil respiration was derived from root respiration. During the rainy season (end of July to September), soil respiration at trenching site and trenching with rainfall interception site were measure during portable soil respiration analyzer (GMP343, Vaisala, Helsinki, Finland). Surprisingly, even after days of continuous heavy rain, soil water content did not exceed 20%. Based on this observation, we suggest that the maximum water holdingcapacity is about 20%, and relatively lower soil water contents during the dry season affect the vital degree of trees and soil microbe. As for soil respiration under different rain intensity, it was increased about 14.4% under 10 mm precipitation. But the high-intensity rain condition, such as more than 10 mm precipitation, caused the decrease of soil respiration up to 25.5%. Taken together, this study suggests that the pattern of soil respiration can be regulated by not only soil temperature but also due to the rain fall intensity.

양버즘나무 (platanus occidentalis L.) 조림지에 있어서 관수와 질소시비량이 토양호흡과 토양미생물에 미치는 영향

이계한 ( Lee Gye Han ) 한국산림과학회 2003 한국산림과학회지 Vol.92 No.5

It is well known that carbon storage capacity of forests will change in response to management practices such as fertilization. However, the influence of fertilization on belowground processes such as soil respiration and microbial biomass is till unclear. I measured soil respiration and microbial biomass along a fertilization gradient(0, 56, and 224 kg N ha^(-1)yr^(-1)) and irrigation in 7-year-old sycamore plantations, established on identical soils, in northwest Florida. Soil respiration was measured monthly from June 2001 to May 2002 using the soda-lime technique. Microbial biomass C, annual litter production, soil temperature, moisture, soil pH, and organic matter were also measured along the same gradient. Annual soil respiration rate was ranged from 527 to 655 g Cm^(-2)yr^(-1). Nitrogen fertilization had a significant negative effect on soil respiration. Mean daily soil respiration rates exhibited a significant exponential relationship with soil temperature(r²=0.53). N fertilization reduced microbial biomass C and increased annual litter production only in 224 N kg ha-1 yr-1 treatment. Annual soil respiration rates were positively correlated with microbial biomass C(r²=0.37). In addition, microbial biomass C was positively correlated with soil organic matter(r²=0.57) and soil pH(r²=0.61). Multiple regression analysis indicated that microbial biomass, soil organic matter, and soil pH were the major factors affecting soil respiration in the sycamore plantation. Total below-ground C allocation estimates were 452, 343, 328, 299, and 254 g Cm^(-2)yr^(-1) for control, irrigation, 56 N, 112 N, and 224 N treatments, respectively. The decrcased below-ground carbon allocation in irrigation and fertilization treatment indicates that a larger portion of production was allocated in the above-ground compared to the water and/or nutrient stressed stands.

Effect of precipitation on soil respiration in a temperate broad-leaved forest

정석희,엄지영,박주연,천정화,이재석 한국생태학회 2018 Journal of Ecology and Environment Vol.42 No.2

Background: For understanding and evaluating a more realistic and accurate assessment of ecosystem carbon balance related with environmental change or difference, it is necessary to analyze the various interrelationships between soil respiration and environmental factors. However, the soil temperature is mainly used for gap filling and estimation of soil respiration (Rs) under environmental change. Under the fact that changes in precipitation patterns due to climate change are expected, the effects of soil moisture content (SMC) on soil respiration have not been well studied relative to soil temperature. In this study, we attempt to analyze relationship between precipitation and soil respiration in temperate deciduous broad-leaved forest for 2 years in Gwangneung. Results: The average soil temperature (Ts) measured at a depth of 5 cm during the full study period was 12.0 °C. The minimum value for monthly Ts was − 0.4 °C in February 2015 and 2.0 °C in January 2016. The maximum monthly Ts was 23.6 °C in August in both years. In 2015, annual precipitation was 823.4 mm and it was 1003.8 mm in 2016. The amount of precipitation increased by 21.9% in 2016 compared to 2015, but in 2015, it rained for 8 days more than in 2016. In 2015, the pattern of low precipitation was continuously shown, and there was a long dry period as well as a period of concentrated precipitation in 2016. 473.7 mm of precipitation, which accounted for about 51.8% of the precipitation during study period, was concentrated during summer (June to August) in 2016. The maximum values of daily Rs in both years were observed on the day when precipitation of 20 mm or more. From this, the maximum Rs value in 2015 was 784.3 mg CO2 m−2 h−1 in July when 26.8 mm of daily precipitation was measured. The maximum was 913.6 mg CO2 m−2 h−1 in August in 2016, when 23.8 mm of daily precipitation was measured. Rs on a rainy day was 1.5~1.6 times higher than it without precipitation. Consequently, the annual Rs in 2016 was about 12% higher than it was in 2015. It was shown a result of a 14% increase in summer precipitation from 2015. Conclusions: In this study, it was concluded that the precipitation pattern has a great effect on soil respiration. We confirmed that short-term but intense precipitation suppressed soil respiration due to a rapid increase in soil moisture, while sustained and adequate precipitation activated Rs. In especially, it is very important role on Rs in potential activating period such as summer high temperature season. Therefore, the accuracy of the calculated values by functional equation can be improved by considering the precipitation in addition to the soil temperature applied as the main factor for long-term prediction of soil respiration. In addition to this, we believe that the accuracy can be further improved by introducing an estimation equation based on seasonal temperature and soil moisture.

강우 이벤트가 태화산 잣나무 식재림의 각 발생원별 CO2 발생량에 미치는 영향

서상욱,박성애,심규영,양병국,최은정,이재석,김태규 한국환경생물학회 2014 환경생물 : 환경생물학회지 Vol.32 No.4

This study was conducted to find out the soil CO2 emission characteristic due to rain fall pattern and intensity changes. Using Automatic Opening and Closing Chambers (AOCCs), we have measured annual soil respiration changes in Pinus koraiensis plantation at Seoul National University experimental forest in Mt. Taehwa. In addition, we have monitored heterotrophic respiration at trenching sites (4×6 m). Based on the one year data of soil respiration and heterotrophic respiration, we observed that 24% of soil respiration was derived from root respiration. During the rainy season (end of July to September), soil respiration at trenching site and trenching with rainfall interception site were measure during portable soil respiration analyzer (GMP343, Vaisala, Helsinki, Finland). Surprisingly, even after days of continuous heavy rain, soil water content did not exceed 20%. Based on this observation, we suggest that the maximum water holding capacity is about 20%, and relatively lower soil water contents during the dry season affect the vital degree of trees and soil microbe. As for soil respiration under different rain intensity, it was increased about 14.4% under 10 mm precipitation. But the high-intensity rain condition, such as more than 10 mm precipitation, caused the decrease of soil respiration up to 25.5%. Taken together, this study suggests that the pattern of soil respiration can be regulated by not only soil temperature but also due to the rain fall intensity.

Effect of rainfall events on soil carbon flux in mountain pastures

Jeong, Seok-Hee,Eom, Ji-Young,Lee, Jae-ho,Lee, Jae-Seok The Ecological Society of Korea 2017 Journal of Ecology and Environment Vol.41 No.11

Background: Large-scale land-use change is being caused by various socioeconomic problems. Land-use change is necessarily accompanied by changes in the regional carbon balance in terrestrial ecosystems and affects climate change. Therefore, it is crucial to understand the correlation between environmental factors altered by land-use change and the carbon balance. To address this issue, we studied the characteristics of soil carbon flux and soil moisture content related to rainfall events in mountain pastures converted from deciduous forest in Korea. Results: The average soil moisture contents (SMC) during the study period were 23.1% in the soil respiration (SR) plot and 25.2% in the heterotrophic respiration (HR) plot. The average SMC was increased to 2.1 and 1.1% in the SR and HR plots after rainfall events, respectively. In addition, saturated water content was 29.36% in this grassland. The soil water content was saturated under the consistent rainfall of more than $5mm\;h^{-1}$ rather than short-term heavy rainfall event. The average SR was increased to 28.4% after a rainfall event, but the average HR was decreased to 70. 1%. The correlation between soil carbon flux rates and rainfall was lower than other environmental factors. The correlation between SMC and soil carbon flux rates was low. However, HR exhibited a tendency to be decreased when SMC was 24.5%. In addition, the correlation between soil temperature and respiration rate was significant. Conclusions: In a mountain pasture ecosystem, rainfall induced the important change of soil moisture content related to respiration in soil. SR and HR were very sensitive to change of SMC in soil surface layer about 0-10-cm depth. SR was increased by elevation of SMC due to a rainfall event, and the result was assumed from maintaining moderate soil moisture content for respiration in microorganism and plant root. However, HR was decreased in long-time saturated condition of soil moisture content. Root has obviously contributed to high respiration in heavy rainfall, but it was affected to quick depression in respiration under low rainfall. The difference of SMC due to rainfall event was causative of a highly fluctuated soil respiration rate in the same soil temperature condition. Therefore, rainfall factor or SMC are to be considered in predicting the soil carbon flux of grassland ecosystems for future climate change.

Spatio-Temporal Variation of Soil Respiration and Its Association with Environmental Factors in Bluepine Forest of Western Bhutan

Cheten Thinley,Baghat Suberi,Rekha Chhetri 강원대학교 산림과학연구소 2023 Journal of Forest Science Vol.39 No.1

We investigated Soil respiration in Bluepine forest of western Bhutan, in relation to soil temperature, moisture content and soil pH and it was aimed at establishing variability in space and time. The Bluepine forest thrives in the typical shallow dry valleys in the inter-montane Bhutan Himalaya, which is formed by ascending wind from the valley bottom, which carries moisture from the river away to the mountain ridges. Stratified random sampling was applied and the study site was classified into top, mid, low slope and further randomized sample of n=20 from 30 m×30 m from each altitude. The overall soil respiration mean for the forest was found 2248.17 CO2 g yr-1 and it is ∼613.58 C g yr-1. The RS from three sites showed a marginal variation amongst sites, lower slope (2,309 m) was 4.64  mol m-2 s-1, mid slope (2,631 m) was 6.78  mol m-2 s-1 and top slope (3,027 m) was 6.33  mol m-2 s-1 and mean of 5.92  mol m-2 s-1, SE=0.25 for the forest. Temporal distribution and variations were observed more pronounced than in the space variation. Soil respiration was found highest during March and lowest in September. Soil temperature had almost inverse trend against soil respiration and dropped a low in February and peak in July. The moisture in the soil changed across months with precipitation and pH remained almost consistent across the period. The soil respiration and soil temperature had significant relationship R2=-0.61, p=0.027 and other variables were found insignificant. Similar relationship are reported for dry season in a tropical forest soil respiration. Soil temperature was found to have most pronounced effect on the soil respiration of the forest under study.