National Forestry Cooperative Federation

Daejeon, South Korea

National Forestry Cooperative Federation

Daejeon, South Korea
Time filter
Source Type

Kawaike K.,Kyoto University | Nakagawa H.,Kyoto University | Kim N.,National Forestry Cooperative Federation | Zhang H.,Kochi University
River Sedimentation - Proceedings of the 13th International Symposium on River Sedimentation, ISRS 2016 | Year: 2017

In numerical simulations of debris flow and evaluations of sabo dam mitigation effects, one of the most important issues is the estimation of overflow discharge across a sabo dam. In this study, under the assumption that complete overflow and free overfall equations are applicable to a one-dimensional (1D) simulation of debris flow, the coefficients of these equations are derived from a regression analysis of experimental results and validated by comparing them with experimental results with two sabo dams.The proposed coefficients for both the equations are related to sediment concentration, which reproduced the time change of flow discharge and sediment concentration overflowing the sabo dam better compared to the conventional values of those coefficients. © 2017 Taylor & Francis Group, London.

Byun J.G.,RWTH Aachen | Lee W.K.,RWTH Aachen | Lee W.K.,Korea University | Kim M.,Korea University | And 10 more authors.
Journal of Plant Ecology | Year: 2013

AimsThis study aimed to develop radial growth models and to predict the potential spatial distribution of Pinus densiflora (Japanese red pine) and Quercus spp. (Oaks) in South Korea, considering topographic and climatic factors.MethodsWe used a dataset of diameter at breast height and radial growth estimates of individual trees, topographic and climatic factors in systematic sample plots distributed over the whole of South Korea. On the basis that radial growth is attributed primarily to tree age, we developed a radial growth model employing tree age as an explanatory variable. We estimated standard growth (SG), defined as radial growth of the tree at age 30, to eliminate the influence of tree age on radial growth. In addition, SG estimates including the Topographic Wetness Index, temperature and precipitation were calculated by the Generalized Additive Model.Important FindingsAs a result of variogram analysis of SG, we found spatial autocorrelation between SG, topographic and climatic factors. Incremental temperature had negative impacts on radial growth of P. densiflora and positive impacts on that of Quercus spp. Precipitation was associated with positive effects on both tree species. Based on the model, we found that radial growth of P. densiflora would be more vulnerable than that of Quercus spp. to climatic factors. Through simulation with the radial growth model, it was predicted that P. densiflora stands would be gradually replaced with Quercus spp. stands in eastern coastal and southern regions of South Korea in the future. The models developed in this study will be helpful for understanding the impact of climatic factors on tree growth and for predicting changes in distribution of P. densiflora and Quercus spp. due to climate change in South Korea. © 2013 © The Author 2013.

Nam K.,Korea University | Lee W.-K.,Korea University | Kim M.,Korea University | Kwak D.-A.,Korea University | And 7 more authors.
Science China Life Sciences | Year: 2015

This study analyzes change in carbon storage by applying forest growth models and final cutting age to actual and potential forest cover for six major tree species in South Korea. Using National Forest Inventory data, the growth models were developed to estimate mean diameter at breast height, tree height, and number of trees for Pinus densiflora, Pinus koraiensis, Pinus rigida, Larix kaempferi, Castanea crenata and Quercus spp. stands. We assumed that actual forest cover in a forest type map will change into potential forest covers according to the Hydrological and Thermal Analogy Groups model. When actual forest cover reaches the final cutting age, forest volume and carbon storage are estimated by changed forest cover and its growth model. Forest volume between 2010 and 2110 would increase from 126.73 to 157.33 m3 hm−2. Our results also show that forest cover, volume, and carbon storage could abruptly change by 2060. This is attributed to the fact that most forests are presumed to reach final cutting age. To avoid such dramatic change, a regeneration and yield control scheme should be prepared and implemented in a way that ensures balance in forest practice and yield. © 2015, The Author(s).

Kim J.-H.,Kangwon National University | Jang J.-H.,Kangwon National University | Ryu J.-Y.,National Forestry Cooperative Federation | Hwang W.-J.,Korea forest Research Institute | And 2 more authors.
Journal of the Korean Wood Science and Technology | Year: 2013

Anatomical characteristics of White Jabon (Arthocephalus cadamba) and Red Jabon (Arthocephalus macrophyllus) were investigated by IAWA hardwood feature list. Both species were diffuse-porous, and radial multiple pore with 2∼3 rows was mostly observed. Tangential diameter of vessel lumina was 100 to 200 μm, and vessels per square millimeter were 5 to 20. White Jabon has more vessels than Red Jabon. The number of solitary pore per square millimeter in both species was similar, but more pore multiple was observed in White Jabon. Axial parenchyma diffuse was observed in both species, but axial parenchyma of White Jabon was hardly identified on the cross section. Rays were classified into "body ray cells procumbent with over 4 rows of upright/square marginal cells" type and partly "all ray cells upright and/or square" type on radial section. Ray width 1 to 3 cells and 1 to 2 cells observed in White Jabon and Red Jabon, respectively. Ray height of White Jabon was 420 μm and Red Jabon 474 μm. Fiber length was the range of 900 to 1,600 μm in both species, and it showed a tendency to increase from pith to bark. Consequently, it is considered that pore multiple, ray width and axial parenchyma are to be suggested the keys for identification of both species.

Kim J.-H.,Kangwon National University | Jang J.-H.,Kangwon National University | Ryu J.-Y.,National Forestry Cooperative Federation | Febrianto F.,Bogor Agricultural University | And 2 more authors.
Journal of the Korean Wood Science and Technology | Year: 2014

The physical and mechanical characteristics of 10 Indonesian wood species were investigated. Mangium, Gandaria and Rambutan showed higher density. Mangium, Gandaria and Mangga appeared lower in shrinkage, and the ratio of tangential/radial was low in Albizia, Kupa and Mangga. The compression strength parallel to the grain and hardness were high in Mangium and Nangka. Gmelina, Mangium, Gandaria, Kupa, Nangka and Rambutan had valuable properties for commercial wood materials. Consequently, it is considered that the results of this study could be useful basic data for the improved use of planted and promising species in Indonesia.

Kwak D.-A.,Korea University | Lee W.-K.,Korea University | Son Y.,Korea University | Choi S.,Boston University | And 7 more authors.
Forest Science and Technology | Year: 2012

This study was performed to estimate the forest cover and volume change using the potential forest cover map and National Forest Inventory (NFI) data of South Korea. The regression models were developed to predict mean diameter at breast height (DBH), tree height (h) and number of trees (Nha) for Pinus densiflora, Pinus koraiensis, Pinus rigida, Larix kaempferi, Castanea crenata and Quercus spp. stand using NFI data. The second step was to prepare potential forest cover maps after 50 and 100 years using the Hydrological and Thermal Analogy Groups (HyTAGs), and then we compared the produced map with the present forest cover map. For the area where forest cover is changed after 50 years, therefore, the volume could be calculated using regression models and DBH and tree height estimated by "age class 1" in this study. On the other hand, the volume of unchanged forest area could be predicted with DBHk+5 and Nhak+5 adding age class 5 (50 years) to the present age class k on the forest cover map. The forest volume after 100 years was also calculated with the same process of after-50 years. As a result, it was predicted that the forest cover would be changed rapidly into Quercus spp. forests for the coming 100 years, accompanying the diminution of coniferous forest. The forest volume would dramatically decrease by 358,719,160 m3 for the coming 50 years because about 80% of coniferous forests are changed into young forests of Quercus spp. by climate change. The forest volume after 100 years would increase to 315,810,920 m3 due to the growth of young forest during 50 years. However, it should be noted that the change of forest cover and volume was estimated without the consideration of mortality, thinning, and tree planting in this study. © 2012 Korean Forest Society.

Kang H.M.,Chonbuk National University | Choi S.I.,Sunchon National University | Ryu J.Y.,National Forestry Cooperative Federation | Lee C.K.,Gyeongnam National University of Science and Technology | Sato N.,Kyushu University
Journal of the Faculty of Agriculture, Kyushu University | Year: 2013

This study intended to seek measures to enhance competitive power and reduce production cost of Korean wood pellet industry through analysis of wood pellet manufacturing cost. For this, the manufacturing cost, total amount of material cost, labor cost, and other expenses occurred in manufacturing process, was analyzed and sensitivity analysis was conducted to understand change of the manufacturing cost depending on material use pattern change and output increase. As the results, it was analyzed that a factor giving the largest effect to the manufacturing cost of wood pellet was material cost and output. Especially, for the material cost, it was identified as more efficient method to reduce the manufacturing cost to produce wood pellet by mixing lumbering byproducts (sawdust) and forest management products (lumbers) in appropriate ratio rather than to use only lumbering byproducts or forest management products. In addition, because material cost per ton is calculated by dividing labor cost and expenses by output, it was identified as a measure to save the manufacturing cost to maintain output corresponding to production capacity of the manufacturer.

Loading National Forestry Cooperative Federation collaborators
Loading National Forestry Cooperative Federation collaborators