• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.548-556
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• 2022

In this study, basic data were obtained to determine the optimal cultivation method to achieve stable fruiting and yield increase in "Cheonhwang" jujube trees. Accordingly, thefructification, fruit characteristics, and yield according to tree age were analyzed. The mean (and range of) tree height, crown area, stem diameter near the root, clear stem length, number of main branches, and distance between main branches were 235.6 (217.4-253.8) cm, 3.5 (3.1-4.1) m², 5.5 (4.0-7.1) cm, 70.6 (66.2-72.7) cm, 9.7 (8.6-10.5), and 10.4 (7.9-14.2) cm, respectively. Correlationanalysis results indicated that tree age was positively correlated with crown area, stem diameter near the root, and clear stem length but not with the number of main branches. The mean number (and range) of fruit per fruit-bearing mother shoot and tree were 18.3 (16.7-18.3) and 170.7 (157.9-178.3), respectively. Tree age was not significantlycorrelated with fruiting characteristics (i.e., the numbers of fruit-bearing mother shoots per main branch, fruit-bearing shoots per fruit-bearing mother shoot, fruit per fruit-bearing shoot, and fruit per tree). Given that the shape of jujube trees is constantly managed according to the growing area and greenhouse type, the tree growth characteristics were more affected by tree management techniques than by tree age. The mean (and range of) fruit weight, fruit hardness, and soluble solid content were 28.6 (27.7-30.3) g, 29.4 (28.5-30.4) N, and 20.4 (19.3-21.0) °brix, respectively, and these fruit characteristics were not significantly correlated with tree age.The average yield per tree of the 'Cheonhwang' jujube cultivar was 4.9 (4.8-5.0) kg, which was not significantly correlated with tree age.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.273-281
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• 1999

In this study, linear programming (LP) was applied to solving for optimal harvesting schedules of multiple-use forest management in Mt. Kari area managed by Chunchun National Forest Station. Associated with the geographic characteristics, the study area was classified into 4 large management units or watersheds and simultaneously applied were the site-specific levels of management constraints : nondeclining yield, initial cut for existing stands, % cut area, the volume of soil erosion, timber production and carbon storage, ending inventory condition and % area species selection for regeneration. The problem was formulated using both Model I and Model II techniques. In this paper, the formulations are presented and the results of the optimal solutions are discussed for comparison purposes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.602-607
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• 2018

The destruction of forests requires continuous management due to the risk of disasters such as landslides and landslides. However, existing forest inspection methods are inefficient as they require a lot of manpower and time. Recently, drones are attracting attention as an effective way to construct and utilize spatial information. The size of the drone-related industrial market is rapidly increasing. In this study, we attempted to increase the efficiency of forest investigation utilizing drones. The study area was photographed through the use of drones, and ortho image and DSM were generated through data processing. Study results found that it was possible to calculate the area and the volume for the forest damaged area effectively by employing drones, and suggested the applicability of drones. In the future, it is expected that the method of analyzing the forested area using drones can save manpower and time compared to existing methods.

• Environmental and Resource Economics Review
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• v.26 no.2
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• pp.229-255
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• 2017

This study empirically estimates the impacts of climate change on forest composition in Korea using a fractional data regression model, and forecasts the change in forest composition in the 2040s and 2090s based on the IPCC climate change scenarios. Unlike the forest science studies that incorporate mostly only ecological variables as the determinants of forest composition, we take into account regional level socio-economic and forest management variables as well. Our estimation results found that not only environmental factors but also socio-economic and forest management related factors strongly affect the composition of Korean forest. Based on the estimation results and IPCC scenarios on climate change, we predict that the share of currently dominant coniferous forest will decline in the future under all scenarios. About 10% of total forest area is likely to be converted from coniferous forest into broadleaved forest until 2090s under the scenario RCP 8.5. It is also predicted that there will be a substantial regional variation in the effects of climate change on forest composition, and the coniferous forests in the inland regions will decline more dramatically.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.4
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• pp.99-112
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• 2021

This study was performed to predict spatial change of future forestland area in South Korea at regional level for supporting forest-related plans established by local governments. In the study, land use was classified to three types which are forestland, agricultural land, and urban and other lands. A logistic regression model was developed using transitional interaction between each land use type and topographical factors, land use restriction factors, socioeconomic indices, and development infrastructures. In this model, change probability from a target land use type to other land use types was estimated using raster dataset(30m×30m) for each variable. With priority order map based on the probability of land use change, the total annual amount of land use change was allocated to the cells in the order of the highest transition potential for the spatial analysis. In results, it was found that slope degree and slope standard value by the local government were the main factors affecting the probability of change from forestland to urban and other land. Also, forestland was more likely to change to urban and other land in the conditions of a more gentle slope, lower slope criterion allowed to developed, and higher land price and population density. Consequently, it was predicted that forestland area would decrease by 2027 due to the change from forestland to urban and others, especially in metropolitan and major cities, and that forestland area would increase between 2028 and 2050 in the most local provincial cities except Seoul, Gyeonggi-do, and Jeju Island due to locality extinction with decline in population. Thus, local government is required to set an adequate forestland use criterion for balanced development, reasonable use and conservation, and to establish the regional forest strategies and policies considering the future land use change trends.

• Journal of Korean Society of Forest Science
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• v.61 no.1
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• pp.60-68
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• 1983

Ever since the day of pre-modernized society where the farming skill had been in the stagnant condition, the common farmwoodlands have been utilized in common (collectivelly) by villagers in order to harvest farmwoodlands and fuelwoods. Later, during the process of modernization, most of the common farmwoodlands were transferred into national or public forests by the administrative enforcement, but there were still various types of village (common) forests such as the common forests owned by joint owners, village block associations, village forest productive societies, Village Forestry Association(V.F.A.), and the national or public forests leased to V.F.A. As Village Forestry Association is organized with a few villages, each of common forests ow nod to the villages is obliged to be diversely controlled by other managers than the chief of V.F.A. Therefore, it is to be desired that the control of common forests should be under Gun Forestry Association Union. While the rate of the use of common forests for fuelwoods and cemetery has been considerably high, villagers wish to promote the timber forest establishment through the collective management by their improved farming skills and economical situations. In these present circumstances the village forest productive societies should be guided to work in closer cooperation with Gun Forestry Association Union. Since the management of common forests is still extensive, it still remains in the semi-management condition under which we can not find any management plan or measure to control forest damage. Especially the small area common forests should have appropriate size for the joint management. This will promote the forest productivity through the lease for reforestation of disposable national forests or public county forests and the contracts for profit sharing. Today owing to increasing forest value, frequent dispute has occurred on the common right telated to the village forests and rationalization of forest management has been disregarded. If a necessary measure were taken to control the dispute such as transferring the registeration right of ownership to the village forest productive society, the confidence of local inhabitants can be regained and the productivity of forests can be naturally increased.

• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.330-344
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• 2022

While deforestation and forest degradation has continued globally, global society has been making efforts to prevent deforestation towards sustainable development. Reforestation in developing countries is linked to Sustainable Development Goals (SDGs) such as climate change mitigation, conservation of biodiversity, eradication of poverty and upholding of human rights. Forest official development assistance (ODA) restores the global forest land, and increases the public benefit. Bilateral forest ODA projects of the Republic of Korea have gradually increased and most of those projects have currently been concentrated in Asian countries. Selecting recipient countries for forest ODA requires more comprehensive approach since the global goals for sustainable development has been widely adapted to ODA strategic plans. We proposed potentially promising countries that are eligible for receiving 'Green ODA' in perspective of economic, social and environment to implement reducing emissions from deforestation and degradation (REDD+), conserving biodiversity, and combating desertification. As a result, the study suggests that forestry cooperation could be expanded from Asian countries more toward South America and African countries. In addition, we emphasized the need to promote convergence and integration with green technology to fundamentally solve the negative impacts of deforestation such as food, energy, water resource shortages, and forest fires. We advocated expanding bilateral ODA in the forestry sector through diversification of project activities, financial sources, and participants. Our study can contribute to the provision of basic information for establishing long-term strategies to expand bilateral cooperation in the forestry sector.

• Journal of Cadastre & Land InformatiX
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• v.46 no.1
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• pp.87-100
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• 2016

The acquisition of the forest resource information has depended on a partial sampling method or aerial photographs which demand a lot of effort and time because of the vast areas and the difficult approach. For the acquisition of the forest resource information, there have been the optical remote-sensing and the multi-spectrum image to offer only horizontal distributions of trees, but a new technological approach, such as Airborne LiDAR, is more necessary to acquire directly three dimensional information related to the forest terrains and trees' features. This paper proposes an algorithm for the forest information extraction such as trees' individual numbers and the heights of trees by using LiDAR data. Especially, this proposed algorithm adopts a region growing method for the extraction of the vegetation-point and extracts the forest information using morphological features of trees.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.299-304
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• 2010

Depending on the progress of the surveying and information processing technology, the rapidly developing field of spatial information and the 3D real world spatial information for a variety of content on the computer was able to easily access. In this research, to study on the spot or to use aerial photographs to measure trees of the acquired data, calculate the trees height, forest area and capacity, determine the distribution of the density of acquired points in the forest and analyze accurate and objective information was acquired. The United States, Canada and so on through the capacity of trees biomass, forest resource analysis, time series monitoring, wildfire behavior modeling and applied research and has been declared. During worldwide is increasing interest in forest resources. In nationally, extensive research and analysis of the forest consists of the correct management and protection of forest resources to be effective.

• Korean Journal of Remote Sensing
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• v.25 no.4
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• pp.311-320
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• 2009

This study was carried out to estimate forest biomass and to produce forest biomass thematic map for Muju county by combining field data from the 5$^{th}$ National Forest Inventory (2006-2007) and satellite data. For estimating forest biomass, two methods were examined using a Landsat TM-5(taken on April 28th, 2005) and field data: multi-variant regression modeling and t-Nearest Neighbor (k-NN) technique. Estimates of forest biomass by the two methods were compared by a cross-validation technique. The results showed that the two methods provide comparatively accurate estimation with similar RMSE (63.75$\sim$67.26ton/ha) and mean bias ($\pm$1ton/ha). However, it is concluded that the k-NN method for estimating forest biomass is superior in terms of estimation efficiency to the regression model. The total forest biomass of the study site is estimated 8.4 million ton, or 149 ton/ha by the k-NN technique.