• 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.

• Journal of Forest and Environmental Science
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• v.36 no.3
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• pp.255-258
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• 2020

Pine wilt disease (PWD) caused by pine wood nematode (PWN), Bursaphelenchus xylophilus, which is transmitted by Monochamus alternatus and M. saltuarius, is a serious threat to coniferous forests in the Northern Hemisphere, including Korea. The efficacy of abamectin and emamectin benzoate for preventing the PWD in the field and its effect on the vectors Monochamus alternatus and M. saltuarius (Coleoptera: Cerambycidae) were evaluated. An experimental plot was delimited, of which consists of Japanese red pine (Pinus densiflora) forest in South Korea, and trunk injection trials were made with abamectin and emamectin benzoate. Branches of each tree were collected, and are subsequently subjected to the analysis of residues for both nematicides. Results obtained in this study showed that abamectin and emamectin benzoate showed over 90% mortality at the recommended concentration after 6 days and 8 days, respectively. Consequently, it was found that both insecticides have a higher effect on the susceptibility and persistence of two vectors of PWD, M. alternatus and M. saltuarius feeding on branches of the trees, and its application by trunk injection is confirmed as an option for pine wilt disease management programs in Korea.

• The Korean Journal of Ecology
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• v.27 no.2
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• pp.67-71
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• 2004

This study was carried out to evaluate soil carbon and nutrient storage of three adjacent coniferous plantations (Larix leptolepis, Pinus densiflora and Pinus rigitaeda) growing on a similar site with a same planting age (42-year old) in the Sambong Exhibition Forests, Hamyang-gun, Gyungsangnam-do. The soil carbon concentration among three plantations was not significantly different in 0∼10cm soil depth, but other two depths (10∼20cm and 20∼30cm) showed higher carbon concentration in P. densiflora plantation than the other two plantations. The exchangeable cation concentrations (Ca and Mg) in 0∼10cm depth were significantly lower in L. leptolepis plantation than in the other two plantations, while nitrogen and phosphorus concentrations were not significantly different among three plantations except for nitrogen at 10∼20cm depth in P. rigitaeda plantation. Soil carbon storage in 0∼20cm depth of three plantations was unaffected by the stand types. Soil nutrient storage was not significantly different at each depth except for nitrogen storage at 10∼20cm depth in P. rigitaeda plantation because of the variation of bulk density and coarse fragment. This result demonstrates that soil carbon and nutrient concentrations among the plantations on a similar soil condition can be altered significantly by tree species effects over 40 years after plantation establishment.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.1 no.1
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• pp.68-73
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• 2020

Korean fir (Abies koreana) is an evergreen coniferous tree species that is unique to South Korea. A. koreana is found in a limited sub-alpine habitat and is considered particularly vulnerable to climate change. Identification of populations vulnerable to climate change is an important component of conservation programs. In this study, a heat stress-induced transcriptome RNA-seq dataset was used to identify a subset of six genes for assessment as candidate marker genes for ecologically vulnerable populations. Samples of A. koreana were isolated from ecologically stable and vulnerable regions of the Halla and Jiri mountains, and the expression levels of the six candidate markers were assessed using quantitative real-time polymerase chain reaction. All six of the candidate genes exhibited higher expression levels in samples from vulnerable regions compared with stable regions. These results confirm that the six high temperature-induced genes can be used as diagnostic markers for the identification of populations of A. koreana that are experiencing stress due to the effects of climate change.

• Korean Journal of Agricultural Science
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• v.27 no.1
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• pp.5-12
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• 2000

The main purpose of this study is to obtain spatial image information toward forest thinning process in Larix forest stands. Thirteen different alternatives were simulated to visualize on the basis of actual thinning work photos. The options were illustrated as photos produced by photoshop program. Each alternatives were evaluated by forest visitor group with total 244 respondents after reliability test. Spatial images of 13 thinning photos were measured by 12 semantic differential scale as broad -narrow, ordered-tangled, friendly-unfriendly, monotonous-divers, dry-refreshing, relieved -stifling, healthy-sickly, uniform-scattered, dead-alive, opened-closed, bent-straight, and beautiful-ugly. In comparison with thinning stands and natural stands, thinning works were visual improvement effects of spatial images. Seemingly, this trend is due to definite form beauty, straight and clear length form of coniferous forest, As can be expected, slash and downwood were negatively related to improvement effects of spatial images. The 60% ratio of stem/ tree height and 450-950 trees/ha was positive in attraction of spatial images. Results indicate how to conduct forest thinning system for spatial images on Larix forest stands.

• Korean Journal of Remote Sensing
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• v.37 no.2
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• pp.291-304
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• 2021

Updating a forest type map is essential for sustainable forest resource management and monitoring to cope with climate change and various environmental problems. According to the necessity of efficient and wide-area forestry remote sensing, CAS500-4 (Compact Advanced Satellite 500-4; The agriculture and forestry satellite) project has been confirmed and scheduled for launch in 2023. Before launching and utilizing CAS500-4, this study aimed to pre-evaluation the possibility of satellite-based tree species classification using RapidEye, which has similar specifications to the CAS500-4. In this study, the study area was the Chuncheon forest management complex, Gangwon-do. The spectral information was extracted from the growing season image. And the GLCM texture information was derived from the growing and non-growing seasons NIR bands. Both information were used to classification with random forest machine learning method. In this study, tree species were classified into nine classes to the coniferous tree (Korean red pine, Korean pine, Japanese larch), broad-leaved trees (Mongolian oak, Oriental cork oak, East Asian white birch, Korean Castanea, and other broad-leaved trees), and mixed forest. Finally, the classification accuracy was calculated by comparing the forest type map and classification results. As a result, the accuracy was 39.41% when only spectral information was used and 69.29% when both spectral information and texture information was used. For future study, the applicability of the CAS500-4 will be improved by substituting additional variables that more effectively reflect vegetation's ecological characteristics.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.540-547
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• 2011

This study was conducted to compare classification accuracy by tree species using QuickBird imagery for pixel- and segment-based classifications that have been mostly applied to classify land covers. A total of 398 points was used as training and reference data. Based on this points, the points were classified into fourteen land cover classes: four coniferous and seven deciduous tree species in forest classes, and three non-forested classes. In pixel-based classification, three images obtained by using raw spectral values, three tasseled indices, and three components from principal component analysis were produced. For the both classification processes, the maximum likelihood method was applied. In the pixel-based classification, it was resulted that the classification accuracy with raw spectral values was better than those by the other band combinations. As resulted that, the segment-based classification with a scale factor of 50% provided the most accurate classification (overall accuracy:76% and ${\hat{k}}$ value:0.74) compared to the other scale factors and pixel-based classification.

• Korean Journal of Environment and Ecology
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• v.38 no.3
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• pp.277-292
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• 2024

In order to manage large-scale forest fires concentrated in Gangwon-do and Gyeongsangbuk-do with severe topographical heterogeneity, a decision-making process through efficient and rapid damage assessment using satellite images is essential. Accordingly, this study targets a large-scale forest fire that ignited in Gangneung and the Donghae, Gangwon-do on March 5, 2022, and was extinguished around 19:00 on March 8, to estimate the fire severity using dNBR and derive environmental factors that affect the grade. As environmental factors, we quantified the regular vegetation index representing vegetation or fuel type, the forest index that classifies tree species, the regular moisture index representing moisture content, and DEM in relation to topography, and then analyzed the correlation with the fire severity. In terms of fire severity, the widest range was 'Unbured' at 52.4%, followed by low severity at 42.9%, medium-low severity at 4.3%, and medium-high severity at 0.4%. Environmental factors showed a negative correlation with dNDVI and dNDWI, and a positive correlation with slope. Regarding vegetation, the differences between coniferous, broad-leaved, and other groups in dNDVI, dNIWI, and slope, which were analyzed to affect the fire severity, were analyzed to be significant with p-value < 2.2e-16. In particular, the difference between coniferous and broad-leaved forests was clear, and it was confirmed that coniferous forest suffered more damage than broad-leaved forest due to the higher fire severity in the Gangwon-do region, including Pinus densiflora, which are dominant species, as well as P. koraiensis, P. rigida and P. thunbergii.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.407-410
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• 1992

Changes in the concentrations of six low-molecular-weight organic acids extracted from hydrolysates of plant residues undergoing decomposition for 90 days under the laboratory condition were investigated. 1. Litters of deciduous and coniferous trees and wild grass cuttings were sampled for the study and concentrations of formic, acetic, succinic, tartaric, malic and citric acids were determined. The concentration of malic acid were negligible. 2. In the wild grass cuttings, the total concentration of low-molecular-weight organic acids decreased with the passage of decomposition. Monocarboxylic acids, I. e., formic and acetic acids, predominated over dicarboxylic and tricarboxylic acids. Formic and acetic acids appeared to be compensatory for each other. Concentration of citric acid increased at a remarkable rate. 3. The total concentration of organic acids in the hydrolysates of deciduous litter was shown to increase. The concentration of monocarboxylic acids was significantly higher in the end of the period of decomposition. Here again a compensatory relationship was observed between concentrations of formic and acetic acids. 4. There was comparatively little change exhibited during the period of experiment concerning the concentrations of organic acids from hydrolysates of decomposing coniferous litter. In contrast with the others, however, the concentration of succinic acid, a dicarboxylic acid, maintained the highest level.

• Journal of Korea Foresty Energy
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• v.23 no.2
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• pp.1-8
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• 2004

This study looked into the change of tree growth of seven forest growth monitoring plots which were set up at the Undulyeong Hongchungun Kangwondo, and was accomplished to offer the basic data for the forest administration calculating carbon storage and removal in the Undulyeong area. Annual height and DBH growth were slowly progressed in the Pinus koraiensis and Larix kaempferi stand which was young stand, but the growth rate of the other stands was lower than those young stand. The diameter class of the mixed forest and Qurcus mongilica stand was predicted to be similar to the now and Pinus koraiensis and Larix kaempferi stand was predicted to move now diameter class to the high diameter class because thickening growth speed of the those stands were rapid. Now the end of 2003, total carbon storage of the Undulyeong model forest increased 149,000TC$(2.7\%)$ compared with the previous year. Seeing by forest types, occupied broad-leaved forest$(50\%)$, mixed forest$(34\%)$ and coniferous forest. During in 2003, total carbon which was removed and stored according to growth of the forest was 156,813TC and net carbon removal(148,664TC) increased into 2,613TC$(1.8\%)$ compared with the previous year. Seeing by forest types, occupied coniferous forest$(3.3\%)$, mixed forest$(3.1\%)$, broad-leaved forest$(2.8\%)$. Resultingly, the Undulyeong model forest is acting to net removal resource when see as green-gas side and net carbon removal are showing the tendency to increase recently little by little.