• Korean Journal of Remote Sensing
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• v.36 no.5_4
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• pp.1209-1220
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• 2020

In the case of forest areas, the installation of ground control points (GCPs) and the selection of terrain features, which are one of the unmanned aerial photogrammetry work process, are limited compared to urban areas, and safety problems arise due to non-visible flight due to high forest. To compensate for this problem, the drone equipped with a real time kinematic (RTK) sensor that corrects the position of the drone in real time, and a 3D flight method that fly based on terrain information are being developed. This study suggests to present a method for investigating damage using drones in forest areas. Position accuracy evaluation was performed for three methods: 1) drone mapping through GCP measurement (normal mapping), 2) drone mapping based on topographic data (3D flight mapping), 3) drone mapping using RTK drone (RTK mapping), and all showed an accuracy within 2 cm in the horizontal and within 13 cm in the vertical position. After evaluating the position accuracy, the volume of the landslide area was calculated and the volume values were compared, and all showed similar values. Through this study, the possibility of utilizing 3D flight mapping and RTK mapping in forest areas was confirmed. In the future, it is expected that more effective damage investigations can be conducted if the three methods are appropriately used according to the conditions of area of the disaster.

• Korean Journal of Environment and Ecology
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• v.31 no.3
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• pp.318-328
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• 2017

In order to provide basic data for the ecological management of forest vegetation in Southern Naeyeon Mountains, A total of 149 sample plots were selected and vegetation survey was carried out by the phytosociological method of the ZM school to classify vegetation types and to grasp ecological characteristics. The forest vegetation was divided into 10 types in terms of species composition, and had a unit hierarchy of 2 community groups, 4 communities, 6 sub-communities and 6 variants. A total of 19 types of physiognomic vegetation were identified based on uppermost dominant species, of which 18 were natural vegetation and 1 was artificial vegetation. As a result of the analysis of the importance values of constituent species, Quercus mongolica, a potentially natural vegetation element, was found to be relatively more important in most stands than other species, and excluding the artificial interference, most of the areas except for some sites would be changed to Q. mongolica forest. In order to understand the spatial distribution of forest vegetation, 1/5,000 large-scale physiognomic vegetation map was created by the uppermost dominant species. As a result, natural vegetation accounted for 98.2%, the number of vegetation patches was 733 and the average area per patch 3.93ha.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.220-225
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• 2012

This study was carried out to clarify the impact of land use (Castanea crenata, Pinus densiflora and Plantation Land) on soil runoff in small watershed. The soil runoff showed in order of plantation land, Castanea stand and Pinus stand. The resulting models in linear equations of three stands were able to account for 70%, 60% and 60% respectively. The relationship between soil runoff and forest environmental factors was a positive correlation at 1% level with slope, forest type, soil hardness, watershed area, stream length and at 5% level with accumulative rainfall, but was negative correlation at 1% level with coverage. The main factors that affected soil runoff in small watershed showed in order of coverage, accumulative rainfall and stand type. In the stepwise regression between soil runoff and forest environmental factors, the estimation equation is as follow; Y = 31.250 - 1.140(Coverage) + 0.413(Accumulative rainfall) + 20.829(Forest type). The results indicates that dangerous areas of landslide and soil runoff by land use could be applied to the mitigation measures such as afforestation, erosion check dam and revetment for erosion control and water quality management in small watershed.

• Journal of Korean Society of Forest Science
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• v.82 no.1
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• pp.1-6
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• 1993

This study was conducted to provide a fundamental information for a income raise of agricultural and mountain villagers and a policy planning by analyzing 145 chestnut producing farms in Korea. The results of this study are as follows : 1. Though the proportion of forest by-products in farm household economy was very slight, it is very important for agricultural and mountain villagers who have relatively lower income level to become a valuable income source. 2. As chestnut cultivating orchards have very small-scale that account for 50.0% of 0.5 to 1.0 hectares and 40.3% of 1.0 to 3.0 hectares reaching 90.3% of total farmers, the small-scale ownership makes the normality and rationalization of management difficult, and therefore the economity of scale has to be accomplished. 3. The difficulties on chestnut cultivating management were in order of the following ; Labour-power shortage(38.5%), desease and pest demage(24.8%), economity(15.2%), management(11.7%), inferiority of site condition(5.9%), technical acquirement(3.8%). 4. In the matter of storaging facilities, 87.6% of total surveyed farmers were recognizing the need of storaging facilities, but only 12.4 of surveyed farmers were possessing these facilities, and therefore the measurement has to be considered such as the forest associations invests to cold storaging facilities unable to privately invest, in order to increase a receiving price of producers.

• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.267-273
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• 2017

This study was conducted to construct a empirical yield table for Pinus densiflora in real forest. Since existing normal yield tables have been derived by studying and analyzing communities in ideal environment for tree growth, those tables provide more over-estimated values than ones from real forest. Because of this, there are some difficulties to apply the tables to empirical forest except for normal forest. In this study, therefore, we estimated stand growth for real forest on P. densiflora as the representative species of conifers. We used 1,957 sample plot data of P. densiflora in central Korea from National Forest Inventory (NFI) system, and analyzed through estimation, recovery and prediction in order by using Weibull function as a diameter distribution model. Weilbull and Schumacher models were applied for estimating mean DBH and mean basel area and it was found that the site index for P. densiflora in central Korea ranges from 8 to 14 at reference age 30. According to site 12 in the stand yield table, the Mean Annual Increment (MAI) of P. densiflora was $4.42m^3/ha$ at 30 years of age. Compared to existing volume table constructed before, it is showed that MAI of this study were lower. According to the paired t-test that is conducted with the gap of volume values between normal forest and real forest by site index and age, the P-value was less than 0.001 which is recognized to have a statistically significant difference. Based on the results in this study, it is considered to be helpful for practical management and management policy on P. densiflora in central Korea.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.705-713
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• 2007

The purpose of this study was to understand the organization and the forestry household income applied the result of 2005 Forestry Census and the Economic survey of Forest household in Korea. As a result of the analysis, there are 97,108 households of a forester in korea 2005. Full time forestry household occupied 7,925 families (8.2%), part time forestry household occupied 88,183 families (91.8%). Therefore, the most household of a forester is part time forestry household in korea. The average people of the household of a forester family is 2.7 people. The age of forest manager are sixties nearly, over sixty years old forest manager occupied 51,505 people (53%). The forest management period of forestry households is more than 6 months in 39,229 families (40.4%), less than 1 month in 7,216 families (7.4%). The average area of forestry households owning forest is 4.6ha. According to the type of business, logging families possesses 19.5 ha. The mean income of forestry households is \27,148,000. One of them, forestry income is \6,529,000, which occupied 24.1%. Furthermore, forestry households less than \5,000,000 forest product sales performance occupied 51,633 families, which is 64%. Forest operating costs is \6,566,000 mean per family. In addition, the number of a forestry household resident villages is 11,829 villages, where is 32.8% of whole villages in korea. There are 2,979 villages where reside forestry household in gyeongsangbuk-do.

• Journal of Korean Society of Forest Science
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• v.97 no.6
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• pp.611-616
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• 2008

The investigation was accomplished on the test area in Forest Practice Research Center in order to compare Point Grid method with Bufferring method in process of the calculation of the Actual Mean Skidding Distance with the GIS aided harvesting method. the investigation site amounted to 264.9 ha in area and 32.67 m in the road density, 306.1 m in road spacing. the Net Correction Factor (Kn) was 1.53 in both sides skidding. the theoretical mean skidding distance was 72.52 m. the shortest mean skidding distance amounted to 149.57 m with point grid method and 139.68 m with Buffering methode. skidding distance correction factor (Kr) was 2.15. actual mean skidding distance amounted to 251.51 m and factor of wood assortment skidding (Kg) was 3.29. when the tractor (Dongyang) and tower yader (Koller 303) are used on investigation site, the logging cost is calculated 11,808 Won with Tractor below 25% slope and 12,336 won with Tractor between 25~55% slope, 10,020 won with Tower Yarder more than 55% slope.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.328-333
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• 2006

This study was conducted to find the characteristics of photosynthesis, leaf and fruit by crown layers in Rubus coreanus Miq. Light compensation points were shown PPFD 33, 20 and $5{\mu}mol\;m^{-2}\;S^{-1}$ at upper, middle and lower layer, respectively. Light saturation points were appeared PPFD 1000, 500 and 200 and their net photosynthesis rate were 8.52, 5.25 and $3.60{\mu}mol\;CO_2\;m^{-2}S^{-1}$ at upper, middle and lower layer, respectively. Uiryeong 7 which was viny type showed higher net photosynthetic rate than others at upper layer. Songgye 6 which was upright type showed lower net photosynthetic rate than others at lower layer. Chlorophyll contents of middle layer had the highest value in the all layers and upper layer showed the lowest value. Most characteristics of leaf morphology were showed that middle and lower layer had higher value than upper layer. That trend was contrary to characteristics of photosynthesis by crown layers. However, dry weight per leaf area and most characteristics of fruit had the highest value at upper layer and that was similar to characteristics of photosynthesis by crown layers. Also, sugar contents of fruit showed the highest value at middle layer.

• Korean Journal of Remote Sensing
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• v.31 no.2
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• pp.77-83
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• 2015

Leaf water content is one of important indicators that shows states of vegetation. It is important to monitor vegetation water content using remote sensing for forest management. In this study, we investigated the degree of water stress in Korean peninsula with Normalized Difference Water Index (NDWI) to study the water content of vegetation canopy. We calculated the NDWI using SPOT/VEGETATION S10 channel data over forest from 1999 to 2013. We calculated Simple Moving Average (SMA) to remove temporal noises of NDWI in time series, and used standardized anomaly to investigate temporal changes. We classified the NDWI anomalies into three scales (low, moderate, and high) in order to monitor intuitively. We also investigated suitability of the NDWI as an evaluation criterion about water stress of vegetation canopy by comparing and verifying forest fires damaged area over 150 ha. Consequently, huge forest fire occurred 24 times during the study period. Also, negative anomalies appeared in every forest fire location and their neighboring areas. In particular, we found huge forest fires where NDWI anomalies were in 'high' scale.

• Journal of Korea Foresty Energy
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• v.22 no.2
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• pp.44-53
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• 2003

This study was conducted to develop new fertilizers which can be applied to various environmental conditions. Fertilizers with different levels of nitrogen, phosphorus and potassium, and different types and amount of combined fertilizers were used on 1-1 seedlings of Pinus densiflora, Larix leptolepis, Quercus acutissima, and Betula platyphylla var. japonica. Biomass, specific leaf area (SLA) and chlorophyll content of foliage were measured. Biomass of foliage, shoot, and root showed no differences among fertilization treatments. Biomass of double treatments of solid-combination fertilizer and UF combination fertilizer increased whereas those of triple treatments decreased. SLA ($\textrm{cm}^2$/g) of P. densiflora fo. the 6:4:1 treatment and L. leptolepis for the 3:4:1 treatment showed the highest with 59.2 and 110.0, respectively, but those of Q. arutissima and B. platyphylla var. japonica for the control showed the higher than other treatments with 207.5 and 202.0, respectively. Chlorophyll contents (mg/g) in the foliage of P. densiflora and L. leptolepis fertilized with the 6:4:1 treatment were 0.222 and 0.127, respectively, and these contents were higher than those of the 3:4:1 treatment with 0.211 and 0.082, respectively. These results suggested that the increased nitrogen fertilization had an effort on increase of chlorophyll contents.