• Journal of Korean Society of Forest Science
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• v.99 no.5
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• pp.693-697
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• 2010

Biomass expansion factors that convert the timber volume (or dry weight) to biomass are used to estimate the forest biomass and account for the carbon budget on a national and regional scale. This study estimated the biomass conversion and expansion factors (BCEF), root to shoot ratio (R), biomass expansion factors (BEF) and ecosystem biomass expansion factor (EBEF) of Korean pine (Pinus koraiensis) forests based on direct field surveys and publications in Korea. The mean BCEF, BEF, and R was 0.6438 Mg $m^{-3}$ (n = 7, SD = 0.1286), 1.6380 (n = 27, SD = 0.1830), and 0.2653 (n = 14, SD = 0.0698), respectively. The mean EBEF, which is a simple method for estimating the understory biomass in Korean pine forest ecosystems, was 1.0218 (n = 6, SD = 0.0090). The values of the biomass expansion factors in this study estimated the Korean pine forest biomass with more precision than the default values given by the IPCC (2003, 2006).

• New & Renewable Energy
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• v.18 no.4
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• pp.70-78
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• 2022

To respond to global warming, there is an increasing interest in eco-friendly alternative energy sources. Therefore, unused forest biomass that has been neglected due to a lack of marketability is attracting attention. With the introduction of the "unused forest biomass certification system" in 2019, ways of determining quantity of unused forest biomass have steadily increased. However, there have been reported cases whereby unused forest biomass weighed more than the amount of harvested trees. It was found that it was possible that forest resources that can be used as round wood were mixed with unused forest biomass. In this context, this study aimed to estimate the amount of mixed round wood in the unused forest biomass supply. The relative expression of growing stock/ha versus the amount of final clearing/ha collected was modeled (y=1.490x-94.341, R²=0.861). As a result, it was found that round wood was mixed into the unused forest biomass, contributing to the disparity observed between the weighted forest biomass and the amount of trees harvested. In conclusion, proper declaration and certification procedures should be carried out for the use of forest resources and promoting unused forest biomass usage.

• Journal of Forest and Environmental Science
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• v.36 no.1
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• pp.17-24
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• 2020

This study aimed to figure out and compare the increment of biomass by thinning intensity focused on the plantation of the two major coniferous species (Larix kaempferi and Pinus koraiensis) of South Korea. The inventory interval was three years under the effects of three types of thinning treatments; control (no thinning), light (20% thinning) and heavy (40% thinning). The results showed standing biomass increment of both species decreased as thinning intensity increased (heavylight>control). Meanwhile, the lowest of on-site biomass changes occurred in the control plot, and the greatest was in the heavy thinning plot because thinning was involved with leaving the felling residual biomass (leaves, branches and roots) on the site. According to the results from this short-term study, unthinned stands is preferable for maximizing standing biomass as well as carbon sequestration. However long-term investigation should be considered in order to see more clear results.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.325-327
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• 2003

Forest biomass is the basis of forest ecosystem. With the rapid development of remote sensing and computer technology, forest biomass estimation using remote sensing data is paid great attention and has acquired great achievements. This article focuses on discussion of methods of forest biomass estimation methods using Terra/MODIS data in Northeast China. The research include: combining the MODIS time series parameters with seasonal characteristics of forest species to identify major forest species; establishing a model to estimate forest biomass based on forest species; analyzing the effects of the existent forest biomass and increasing biomass on terrestrial carbon cycle. This research can help to make clear the mechanism of carbon cycle.

• Journal of Korean Society of Forest Science
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• v.98 no.4
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• pp.409-416
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• 2009

Forest biomass estimation is essential for greenhouse gas inventories and terrestrial carbon accounting. Remote sensing allows for estimating forest biomass over a large area. This study was conducted to estimate forest biomass and to produce a forest biomass map for Muju county using forest biomass conversion table developed by field plot data from the 5th National Forest Inventory and Landsat TM-5. Correlation analysis was carried out to select suitable independent variables for developing regression models. It was resulted that the height class, crown closure density, and age class were highly correlated with forest biomass. Six regression models were used with the combination of these three stand variables and verified by validation statistics such as root mean square error (RMSE) and mean bias. It was found that a regression model with crown closure density and height class (Model V) was better than others for estimating forest biomass. A biomass conversion table by model V was produced and then used for estimating forest biomass in the study site. The total forest biomass of the Muju county was estimated about 8.8 million ton, or 128.3 ton/ha by the conversion table.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.317-330
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• 2022

Recently, the policy regarding climate change in Korea and overseas has been to promote the utilization of forest biomass to achieve net zero emissions. In addition, with the implementation of the unused forest biomass system in 2018, the size of the Korean market for manufacturing wood pellets and wood chips using unused forest biomass is rapidly expanding. Therefore, it is necessary to estimate the total amount of unused forest biomass that can be used as an energy source and to identify the capacity that can be continuously produced annually. In this study, we estimated the actual forest area that can be produced of logging residue and the potential amount of unused forest biomass resources based on GT (green ton). Using a forest functions classification map (1 : 25,000), 5th digital forest type map (1 : 25,000), and digital elevation model (DEM), the forest area with a slope of 30° or less and mountain ridges of 70% or less was estimated based on production forest and IV age class or more. The total forest area where unused forest biomass can be produced was estimated to be 1,453,047 ha. Based on GT, the total amount of unused forest biomass potential resources in Korea was estimated to be 117,741,436 tons. By forest type, coniferous forests were estimated to be 48,513,580 tons (41.2%), broad-leaved forests 27,419,391 tons (23.3%), and mixed forests 41,808,465 tons (35.5%). Data from this research analysis can be used as basic data to estimate commercial use of unused forest biomass.

• Journal of Forest and Environmental Science
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• v.20 no.1
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• pp.110-130
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• 2004

This study aims to study the definition and characteristics of forest biomass as an alternative energy and to estimate the energy potential and feasibility of forest biomass utilization in domestic. Especially, significant attention is given to woody biomass such as forest residue, thinning log, etc. due to their renewable, sustainable and abundant properties. The results were summarized as follows. The utilization of these forest biomass could play an important role to activate the forest industry and increase the public benefit functions of forest, but more attention on their utilization is required and how they can be utilize more efficiently is the new task assigned to our forestry for sustainable forest management.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.4
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• pp.15-24
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• 2009

This paper estimates the nation wide amount of forest biomass arising from management operation for domestic forest based on the simulations that are composed of five scenarios for selecting the target area of thinning. In 2009, the forest biomass arising from thinning is estimated to be 6,642,174 $m^3$. The estimates of forest biomass in 2015 and 2018 are 5,935,140 $m^3$ and 5,682,538 $m^3$, respectively. Since the target forest for thinning policy is estimated to be decreasing, the biomass generated by thinning will decline too. The estimates of forest biomass can be used to induce more effective application of woody biomass rather than one-sided use such as raw materials for solid fuels including pellets and charcoals.

• Journal of Forest and Environmental Science
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• v.29 no.1
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• pp.81-89
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• 2013

Nowadays, excessive using of fossil fuel contributes to global warming. Also, this phenomenon increases steadily. Therefore forest biomass from logging residues has received attention. The goal of this study was to determine the sustainability and economic feasibility of forest-biomass energy source. Accordingly, forest biomass resource was calculated, and harvesting and transporting machines which can be used in investing area were chosen, when using forest biomass as energy source. And then through these data, the harvesting cost was decided. The forest biomass resource calculated, thinned trees and logging residues, was 37,330.23 $m^3$ and 14,073.60 ton, respectively. When harvesting timber in each sub-compartment, the average thinned trees yield was 120.73 $m^3$, and tree logging residues was 402.80 ton. The use of tower yarder as harvesting and transporting equipments in study area was 85.4% and 66.7%, respectively, in up hill and down hill yarding. The average harvesting cost of biomass in the possibility area of timber yarding operation was expensive as 81,757 won/$m^3$, 85,434 won/m3 and 50,003 won/ton, respectively, in thinned trees and logging residue. If using data from this research analysis, tree could be felled by choosing sub-compartment.

• Journal of Forest and Environmental Science
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• v.37 no.2
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• pp.128-140
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• 2021

Tropical dry forests are one of the most threatened, widely distributed ecosystems in tropics and estimation of forest biomass is a crucial component of global carbon emission estimation. Therefore, the present study was aimed to quantify the biomass and carbon storage in trees on large scale (10, 1 ha plots) in the dry mixed evergreen forest of Javadhu forest of Eastern Ghats. Biomass of adult (≥10 cm DBH) trees was estimated by non-harvest methods. The total biomass of trees in this tropical dry mixed evergreen forest was ranged from 160.02 to 250.8 Mg/ha, with a mean of 202.04±24.64 Mg/ha. Among the 62 tree species enumerated, Memecylon umbellatum accumulated greater biomass and carbon stocks (24.29%) more than the other species in the 10 ha study plots. ANOVA revealed that there existed a significant variation in the total biomass and carbon stock among the three plant types (Evergreen, brevi-deciduous and deciduous (F (2, 17)=15.343, p<0.001). Basal area and density was significant positively correlated with aboveground biomass (R² 0.980; 0.680) while species richness exhibited negative correlation with above ground biomass (R² 0.167). Finding of present study may be interpreted as most of the trees in this forest are yet to be matured and there is a net addition to standing biomass leading to carbon storage.