• Journal of Ecology and Environment
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• v.48 no.3
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• pp.382-394
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• 2024

Background: Humbo Farmer Managed Natural Regeneration (FMNR) forest is managed through direct involvement of the local community and funded by the World Vision Australia through World Vision Ethiopia under framework of the Kyoto Protocol's Clean Development Mechanism on greenhouse gas emissions. Understanding the amount and distribution of carbon stored in forests across different elevations will enhance ability to anticipate how forests will react to future climate conditions and carbon levels. The aim of the study was to quantify the amount of carbon stocks along altitudinal gradients in the Humbo FMNR forest in southern Ethiopia. A total of 54 nested sample plots of 20 m × 20 m were established on transects of elevation gradients. Inventories of woody species and soil samples (0-10 cm and 10-20 cm depth) were collected within each nested sample plot. Carbon stocks in woody biomass and soil were compared by three elevation classes. Results: The total carbon stocks significantly (p < 0.05) differed among the three altitudinal gradients. There is no significant difference in biomass carbon stocks between the middle (1,610-1,750 m above sea level [a.s.l.]) and lower (1,470-1,610 m a.s.l.) elevations. However, both of these elevations significantly differ (p < 0.05) from the higher (1,750-1,890 m a.s.l.) elevation, despite an increase in carbon stocks from lower to higher elevations. The highest ecosystem carbon stock was contributed by soil carbon. The higher proportion of C stocks at the higher elevations may be associated to the species composition and dominance with larger wood density. Conclusions: It was concluded that even though soil carbon contributed higher carbon to the total carbon stock, biomass is stronger impact than soil carbon when it comes to carbon stock variation by altitudinal gradients. We recommend that carbon-related awareness creation on reducing emission for the local people and promotion of knowledge on carbon stock credits accounting and to be claimed in future for financing, which could be considered as additional possible option for sustainable forest management.

• Atmosphere
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• v.33 no.1
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• pp.61-72
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• 2023

Accurate estimation of forest carbon stocks is important in establishing greenhouse gas reduction plans. In this study, we estimate the spatial distribution of forest carbon stocks using machine learning techniques based on high-resolution remote sensing data and detailed field survey data. The high-resolution remote sensing data used in this study are Landsat indices (EVI, NDVI, NDII) for monitoring vegetation vitality and Shuttle Radar Topography Mission (SRTM) data for describing topography. We also used the forest growing stock data from the National Forest Inventory (NFI) for estimating forest biomass. Based on these data, we built a model based on machine learning methods and optimized for Korean forest types to calculate the forest carbon stocks per grid unit. With the newly developed estimation model, we created forest carbon stocks maps and estimated the forest carbon stocks in South Korea. As a result, forest carbon stock in South Korea was estimated to be 432,214,520 tC in 2020. Furthermore, we estimated the loss of forest carbon stocks due to the Donghae-Uljin forest fire in 2022 using the forest carbon stock map in this study. The surrounding forest destroyed around the fire area was estimated to be about 24,835 ha and the loss of forest carbon stocks was estimated to be 1,396,457 tC. Our model serves as a tool to estimate spatially distributed local forest carbon stocks and facilitates accounting of real-time changes in the carbon balance as well as managing the LULUCF part of greenhouse gas inventories.

• Journal of Ecology and Environment
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• v.43 no.1
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• pp.43-60
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• 2019

Background: Tropical montane forests played an important role in the provision of ecosystem services. The intense degradation and deforestation for the need of agricultural land expansion result in a significant decline of forest cover. However, the expansion of agricultural land did not completely destruct natural forests. There remain forests inaccessible for agricultural and grazing purpose. Studies on these forests remained scant, motivating to investigate biomass and soil carbon stocks. Data of biomass and soils were collected in 80 quadrats ($400m^2$) systematically in 5 forests. Biomass and disturbance gradients were determined using allometric equation and disturbance index, respectively. The regression modeling is employed to explore the spatial distribution of carbon stock along disturbance and environmental gradients. Correlation analysis is also employed to identify the relation between site factors and carbon stocks. Results: The result revealed that a total of 1655 individuals with a diameter of ${\geq}5cm$, representing 38 species, were measured in 5 forests. The mean aboveground biomass carbon stocks (AGB CS) and soil organic carbon (SOC) stocks at 5 forests were $191.6{\pm}19.7$ and $149.32{\pm}6.8Mg\;C\;ha^{-1}$, respectively. The AGB CS exhibited significant (P < 0.05) positive correlation with SOC and total nitrogen (TN) stocks, reflecting that biomass seems to be a general predictor of SOCs. AGB CS between highly and least-disturbed forests was significantly different (P < 0.05). This disturbance level equates to a decrease in AGB CS of 36.8% in the highly disturbed compared with the least-disturbed forest. In all forests, dominant species sequestrated more than 58% of carbon. The AGB CS in response to elevation and disturbance index and SOC stocks in response to soil pH attained unimodal pattern. The stand structures, such as canopy cover and basal area, had significant positive relation with AGB CS. Conclusions: Study results confirmed that carbon stocks of studied forests were comparable to carbon stocks of protected forests. The biotic, edaphic, topographic, and disturbance factors played a significant variation in carbon stocks of forests. Further study should be conducted to quantify carbon stocks of herbaceous, litter, and soil microbes to account the role of the whole forest ecosystem.

• Korean Journal of Ecology and Environment
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• v.57 no.3
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• pp.123-133
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• 2024

To analyse the relationship between above-ground carbon stocks, species diversity and broadleaved forests structural diversity of South Korean forests, we collected vegetation inventories from environmental impact assessment projects over the past 10 years. The available data were selected and organised including tree species, DBH and area each projects. The data was classified by forest type, aboveground carbon stocks were calculated and compared, and the correlation between aboveground carbon stocks and biodiversity and structural diversity was analysed. The results showed that above-ground carbon stocks were higher in mixed forests and broadleaved forests and lower in needleleaved forests, similar to previous studies. However aboveground carbon stocks of mixed forests were higher in natural forests than in plantations. Aboveground carbon stocks in broadleaved forests were higher in plantations than natural forests, and there was no statistical different of between natural and plantations in needleleaved forest. This could be the result of a variety influences including biological and environmental factors in the study area, and further research is needed to analyse the effects on carbon sequestration. Correlation analysis showed no correlation between biodiversity and above-ground carbon stocks, but a positive correlation between structural diversity and above-ground carbon stocks. This indicates that above-ground carbon stocks in forests are associated with unevenness diameters and the proportion and evenness of tree species by diameter. In addition, it has been analysed that the high succession stages in forest have higher species diversity and structural diversity, and greater efficiency in the utilization of resources required for plant growth, leading to increased plant productivity and storage. Considering that the study sites were young forests with an average DBH of 14.8~23.7 cm, it is expected that carbon stocks will increase as biodiversity and structural diversity increase. Further research is needed to develop techniques to quantitatively assess the relationship of diversity to carbon stocks for policy use in assessing and increasing carbon stocks in forests.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.5
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• pp.27-41
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• 2024

The current method of calculating the carbon stocks of Korea's forests is to multiply the forest standing crop by basic wood density, biomass expansion factor, and carbon fraction, but it does not sufficiently reflect forest vegetation. This study attempted to present a method of calculating carbon stocks using the biotope map and Biomass Allometric Equations for forests in Suji-gu, Yongin City. The biotope map is prepared every five years and contains detailed information on vegetation, including the actual vegetation and land cover status. The forest biotope of Suji-gu was extracted from the Yongin City biotope map, and the tree species, height, and breast height diameter of 24 representative types of forest vegetation sampled in Yongin City were analyzed in detail. To calculate the carbon stocks of trees and shrubs, the Biomass Allometric Equations developed by the National Institute of Forest Science was used, and to calculate the carbon stocks of shrubs, the previous research result of 0.457 kg per m² was applied. First, carbon storage was calculated for each types of forest vegetation sampled in Yongin City, and in order to apply this to the entire area, the 125 forest vegetation types in Suji-gu, Yongin City were retyped into 50. As a result, the Quercus mongolica community occupied the largest area, followed by the Pinus rigida community, the Quercus acutissima community, and the Quercus serrata community. The community with the highest carbon stocks per unit area (m²) was the Cornus controversa-Quercus mongolica community, and the community with the lowest was the oak-Betula dahurica community. The carbon stocks amount of forests in Suji-gu, Yongin City, calculated by applying the biotope map and Biomass Allometric Equations, was relatively higher than the carbon stocks amount calculated by multiplying existing forest standing crop by basic wood density, biomass expansion factor, and carbon fraction. This is because the currently officially used forest standing crop in Yongin City (144.44 m³/ha) does not sufficiently reflect the actual forest vegetation, and trees with a breast height diameter of less than 6 cm were excluded when surveying forest standing crop, resulting in a lower carbon stocks amount than the actual amount. This study complements the limitations of existing carbon stocks calculation methods by utilizing a biotope map with detailed information on vegetation, such as existing vegetation maps and land cover status, and a Biomass Allometric Equations developed by the National Institute of Forest Science, and provides higher precision when assessing carbon stocks of forests. It is meaningful in suggesting a method for calculating carbon stocks.

• Journal of Korean Society of Forest Science
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• v.111 no.3
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• pp.365-373
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• 2022

We compared carbon stocks in tree biomass and soils of Quercus acutissima, Q. mongolica, Q. serrata, and Q. variabilis stands. A total of 531 plots (Q. acutissima: 110 plots, Q. mongolica: 177 plots, Q. serrata: 96 plots, Q. variabilis: 148 plots) were examined between 2016 and 2021 to determine the tree biomass and soil carbon stocks throughout the country. The carbon stocks of tree biomass were significantly higher in Q. mongolica (mean stand age, 57 years, 144.9 Mg C ha^-1) than in Q. variabilis (mean stand age, 43 years, 123.7 Mg C ha^-1), Q. serrata (mean stand age, 43 years, 120.1 Mg C ha^-1), and Q. acutissima (mean stand age, 36 years, 113.2 Mg C ha^-1) stands. The soil carbon concentration was significantly higher in Q. mongolica (A: 43.1 mg C g-1) than in Q. serrata (31.0 mg C g-1), Q. variabilis (25.31 mg C g-1), and Q. acutissima (24.4 mg C g-1) stands. The soil carbon stocks were significantly higher in Q. mongolica (116.8 Mg C ha^-1) than in Q. acutissima (49.3 Mg C ha^-1) stands. Total carbon stocks of tree biomass and soil were highest in Q. mongolica (262 Mg C ha^-1), followed by Q. serrata (218 Mg C ha^-1), Q. variabilis (211 Mg C ha^-1), and Q. acutissima (163 Mg C ha^-1) stands. Multiple linear regressions were performed to estimate the total carbon stocks of the four Quercus spp., and results showed that total carbon stocks increased with increasing elevation, mean diameter at breast height, and basal areas. Basal area and elevation of Quercus spp. stands were important explanatory variables based on multiple linear regressions for estimating carbon stocks.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.330-338
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• 2023

To investigate the impact of forestry projects on the carbon stocks of forests, we estimated the carbon stock change of above-ground and soil before and after forestry projects using forest type maps, forestry project information, and soil information. First, we selected six map sheet with large areas and declining age class based on forest type map information. Then, we collected data such as forest type maps, growth coefficients, soil organic matter content, and soil bulk density of the estimated areas to calculate forest carbon storage. As a result, forest carbon stocks decreased by about 34.1~70.0% after forestry projects at all sites. In addition, compared to reference studies, domestic forest soils store less carbon than the above-ground, so it is judged that domestic forest soils have great potential to store more carbon and strategies to increase carbon storage are needed. It was estimated that the amount of carbon stored before forestry projects is about 1.5 times more than after forestry projects. The study estimated that it takes about 27 years for forests to recover to their pre-thinning carbon stocks following forestry projects. Since it takes a long time for forests to recover to their original carbon stocks once their carbon stocks are reduced by physical damage, it is necessary to plan to preserve them as much as possible, especially for highly conservative forests, so that they can maintain their carbon storage function.

• Journal of the Korean association of regional geographers
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• v.20 no.2
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• pp.206-216
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• 2014

In this study, forest types in Chungheongnam-do were analyzed using Landsat satellite images and digital forest type map as a means to estimate forest carbon stocks. NDVI and Tasseled Cap, ISODATA, and supervised classification among others were used to analyze the forest types. The forest carbon stocks of Chungcheongnam-do were estimated utilizing forest statistical data derived from the classified results. The results indicate that the analysis of forest types through supervised classification yielded the highest overall accuracy in analyzing forest types using satellite images. Coniferous forests(49.3%) accounted for the highest proportion in all the forest types of Chungcheongnam-do, followed by deciduous forests(28.0%) and mixed forests(22.7%). The results of a comparative analysis between forest carbon stocks estimates made using the modified digital forest type map and other estimation methods showed that the method using Tasseled Cap and unsupervised classification yielded the most similar forest carbon stock estimates. The most significant difference, though, was made when only the digital forest type map was used. It is expected that if carbon stocks are estimated by integrating satellite images and digital forest type maps in the future, more accurate results can be derived in estimating forest carbon stocks at a national level.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.708-714
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• 2011

Wood store carbon that the forest absorbed until burned or decomposed over a long period. Such materials are most used in houses except in paper and pulp, and the use of wood in houses play an important role in reducing green-house gases. Therefore, we estimated the amount of carbon stocks in Korean houses, and analyzed how much contribution such stocks offers to green-house gas reduction. As the result, the carbon stocks amount of the wood products in Korean houses was 28.4 million $tCO_2$, which is 4.6% of the total annual green-house gas emission in Korea (620 million $tCO_2$ e), and 77.4% of forest sinks (LULUCF). Even though few wooden houses which use most wood in housing exist in Korea, the carbon stocks of wood products in houses in 2010 increased to 4.1 times that in 1975 (21.4 million $tCO_2$) because the carbon stocks increased due to apartment construction, which hit its stride from the last 1980's.

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.233-243
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• 2021

Considering worldwide efforts to mitigate repercussions of climate change, the South Korean government has declared to reach net zero by 2050 to achieve a carbon-neutral sustainable society. For full implementation of NDCs, the government has actively reflected its forestry sector into these strategies. Since coarse woody debris (CWD) in forests represents an enduring carbon storage, it is of particular significance to determine characteristics of changes in carbon stocks of CWD by utilizing data on dead trees monitored in permanent sample plots within national forest inventories (NFIs). In this study, therefore, both occurrence and carbon stocks of CWD were estimated in such plots using data on CWD from the 5^th, 6^th, and 7^th NFIs. Subsequently, characteristics of changes in carbon stocks over time were analyzed. Based on the analysis of 2,021 plots available for monitoring in each NFI of Gangwon Province, the volume of CWD (m³ ha^-1) was found to be 4.71 in the 5^th NFI and 4.09 in the 6^th NFI. However, the volume of CWD declined to 3.09 in the 7^th NFI. Moreover, the annual carbon stocks of CWD (ton C ha^-1) were estimated to be 0.67 in 2009, 0.64 in 2014, and 0.41 in 2019, showing a downward trend over time. This study provides a basis for future research to investigate long-term changes and estimate carbon stocks of CWD in South Korea forests.