• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.240-245
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• 2011

Vegetation changes were studied for 16 yr in clearcut logged Pinus densiflora forests in the southern Gangwon-do province in Korea by applying chronosequence approach. Ambient temperature and relative humidity, Detrended Correspondence Analysis (DCA), Multiple Responses Permutation Procedure (MRPP), Indicator Species Analysis (ISPAN) were used to examine successional trajectory and compositional changes. After clearcutting, canopy openness was increased abruptly at three folds (1yr 68.3% and R1 23.0%) and then decreased, but relative moisture was slightly decreased (6%) compare to control site. In the result of DCA, right after clear cutting, vegetation composition was developed heterogeneously compared to control sites, and then approached to control sites within 16 years. Based on MRPP, species composition of each developmental stages (1yr, 3yr, 10yr and 16yr) revealed signigicant differences to that of control vegetation (R1, R3, R10 and R16). Indicator species in 1yr and 3yr samples included various woody species rather than herbaceous species, but in 10yr and 16yr, herbaceous were more abundant. Earlier succession of pine forests likely can explain to Initial Floristic Composition (IFC) Model.

• Korean Journal of Environment and Ecology
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• v.36 no.4
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• pp.413-421
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• 2022

This study was conducted to identify the vegetation structure of the Abies nephrolepis forests by analyzing species composition in Mt. Doota and Mt. Cheongok in the Gangwon region with the phytosociological method. In order to perform a field investigation, 18 survey areas with an area of about 400 m2 were set up for the stands where A. nephrolepis grow wild. Communities were classified through TWINSPAN and visualized using DCA (Detrended Correspondence Analysis). Species diversity analysis, importance value analysis, and DBH class analysis were employed to identify the characteristics of each community. As a result, the A. nephrolepis forests in Mt. Doota and Mt. Cheongok have been classified into 4 communities; GroupI, II, III and IV. GroupIis Quercus mongolica-A. nephrolepis competitive forest dominated by Q. mongolica and A. nephrolepis in the order. Group II is A. nephrolepis-Betula ermanii competitive forest dominated by A. nephrolepis, Sorbus commixta, and B. ermanii in the order. Group III is dominated by A. nephrolepis, but is expected to have competition between A. nephrolepis and Q. mongolica in the future due to the mass occurrence of Q. mongolica saplings. A. nephrolepis, S. commixta, and Q. mongolica are the dominant species in Group IV, and A. nephrolepis is the major dominant species in all layers. The species diversity of the A. nephrolepis forests in Mt. Doota and Mt. Cheongok is lower than other A. nephrolepis forests in Mt. Seorak, Maruguem, and Mt. Odae. It is necessary to establish conservation measures and to continuously monitor the A. nephrolepis forests in Mt. Doota and Mt. Cheongokis due to the harsh environment and the competition that may occur between A. nephrolepis and deciduous trees such as Q. mongolica in the future.

• Journal of the Korean Wood Science and Technology
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• v.32 no.2
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• pp.90-95
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• 2004

Pitch pine (Pinus rigida) has been planted in Korean forests for several decades, primarily for erosion control and use as a fuel supply. To enhance its value, and especially potential use as lamina for structural glued laminated timber (glulam), log quality and lumber yield of pitch pine were evaluated in this study. Trees from pure pitch pine stands with an average diameter at breast height of 32 cm were felled and bucked into 3.6m long 15 cm minimum butt-end diameter logs. Over 80% of the logs were classified to No.2 or No.3 visual grade group. Upon sawing total lumber yield was 55.2%, 39.9% for structural glulam lamina, 7.2% for louver, and 8.1% for miscellaneous use. The final lumber yield for manufacturing structural glulam, after cross-cutting to eliminate knots and finger jointing, was only 15.3%. To enhance this manufacturing yield requires that the rate of knot-included lumber used as lamina be raised. However arrangement of the knot-included lamina, whose mechanical properties need to be accurately evaluated, must be optimized to minimize any reduction to the structural glulam strength. The log quality and lumber yield of pitch pine evaluated in this study are expected to facilitate proper planning for wood product manufacture in the Korean lumbering and glulam industrial field, which has not previously dealt with this species.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.55-64
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• 2000

This study was carried out to analyze the characteristics of pH and electrical conductivity(EC) at each stand and soil depth by the artificial acid rain sprinkling in the upper watershed of Mt. Palgong and furthermore to clarify the relationships between forest soil and water purification function. The results obtained in the experimental sites of Quercus acutissima and Larix leptolepis were summarized as follows ; 1. The average soil pH at each soil layer(0~5cm, 0~10cm, 0~20cm in depth) were 4.8, 4.3 and 4.5 for the Quercus acutissima soil and 5.15, 5.19 and 5.21 for the Larix leptolepis soil. The soil pH of Larix leptolepis stand was higher than that of Quercus acutissima stand. In addition, the deeper soil depth was, the higher soil pH was. 2. The soil solution pH of Larix leptolepis stand was higher than that of Quercus acutissima stand. It was due to the high soil pH of Larix leptolepis stand itself and the difference of humus layer thickness. 3. It took time to show the pH buffer capacity of forest soil after application of artificial acid rain in the forest soil. The pH value of soil solution in each experimental site was maximum at this time and then did not increase pH value any more. 4. Soil solution EC increased slowly with pH 3.0 treatment, but it decreased slowly with pH 5.0 treatment over time. It was assumed that the amount of the leached cation and the ions leading buffer action changed at the stands with ranges of acidity treatment. 5. From the trend of soil solution EC at each soil depth, it seemed that the water buffer capacity of the forest soil increased as the soil depth increased.

• Korean Journal of Remote Sensing
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• v.31 no.5
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• pp.385-394
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• 2015

Pine wilt disease has greatly damaged pine forests not only in East Asia including South Korea and China, but also in European region. The damage caused by pine wood nematode (Bursaphelenchus xylophilus) is expressed in bundles within stands and rapidly spreading, however, present field survey methods have limitations to detecting damaged trees at regional level. This study extracted the damaged trees by pine wilt disease using time series hyperspectral aerial photographs, and analyzed their distribution characteristics. Hyperspectral aerial photographs of 1 meter spatial resolution were obtained in June, September, and October. Damaged trees by pine wilt disease were extracted using Normalized Difference Vegetation Index (NDVI) and Vegetation Index green (VIgreen) of the September photograph. Among extracted damaged trees, dead trees with leaves and without leaves were classified, and the spectral reflectance values from the photographs obtained in June, September, and October were compared to extract new outbreaks in September and October. Based on the time series dispersion of extracted damaged trees, nearest neighbor analysis was conducted to analyze distribution characteristics of the damaged trees within the region where hyperspectral aerial photographs were acquired. As a result, 2,262 damaged trees were extracted in the study area, and 604 dead trees (dead trees in last year) with leaves in relation to the damaged time and 300 and 101 newly damaged trees in September and October were classified. The result of nearest neighbor analysis using the data shows that aggregated distribution was the dominant pattern both previous and current year in the study area. Also, 80% of the damaged trees in current year were found within 60 m of dead trees in previous year.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.567-582
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• 2022

Chainsaw use for motor-manual timber harvesting in South Korea is associated with worker safety issues. However, forestry operations such as timber harvesting have already been mechanized to reduce hazards to workers and increase productivity. This study analyzed the productivities and costs of felling and processing, felling and processing using an excavator-based stroke harvester for Pinus rigida and Quercus mongolica stands. To efficiently operate the stroke harvester, we developed a regression equation to estimate the productivities of felling and processing, felling, and processing operations,and we conducted sensitivity analysis of the operation costs using DBH and machine utilization. The felling and processing productivity was 6.53 and 4.02 m³/SMH for P. rigida a nd Q. mongolica, respectively, and the cost was 17,983 and 29,210 won/m³, respectively. The felling productivity for P. rigida a nd Q. mongolica wa s 40.9 and 23.0 m³/SMH, respectively, and the cost was 2,667 and 4,743 won/m³, respectively. The processing productivity for P. rigida and Q. mongolica was 8.25 and 7.75 m³/SMH, respectively, and the cost was 15,296 and 16,283 won/m³, respectively. In the developed regression equation, the DBH, traveling distance, and number of cuttings were found to be important factors (p<0.05). Therefore, it is necessary to construct a DB considering the various conditions and species associated with harvester operations, and further research is needed to increase the accuracy of predicting operation productivity and costs.

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.391-413
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• 1994

The northernmost type of the monogolian oak forests in the Russian Far East was studied in terma of syntaxonomy and synchorology. Hand-sorting method, computer program TWIN-SPAN, CANOCO and SYN-TAX III were engaged for the classification and data analysis. Correlation between plant communitie and environmental factors was analyzed by DCA (Detrended Correspondence Analysis) using NeCD (Net Contribution Degree) of species. Three plant communities were recognized: the Abieti holophyllae-Quercetum mongolicae, the Lespedezo-quercetum mongolicas and the Rosa ussuriensis-Quercus mongolica communit. They were included into the alliance Jeffersonio-Quercion monogolicae which is representative to the cool-Temperate forests mixed by conierous and broadleaved trees in southern Sikhote Alin. Human impact was signified as the most important factor to interpret the disjunction of plant communities of which DCA ordination yielded sharp contrasting objects (i.e. stands and species). In the amhi-Tonghae region, alaogous vegetation types such as the Jeffersonio-Quercion monogolicae of Russian Far East, the Quercion grosseserratae of Japanese Hokkaido and the Pino koraiensis-Quercion monogolicae of Koream peninusula were reviewed in terms of similarity of species composition and stratum structure. It is signified that the Jeffersonio-Quercion monogolicae was one of the continental types more similar to Korean alliance that to Japanese one.

• Korean Journal of Microbiology
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• v.6 no.3
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• pp.92-92
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• 1968

1) The aim of present investigation is to elucidate the relation of the balance of the production and decomposition of the fir litter. in Kwangnung plantation stands. 2) The decay constant, K, of litters was 0. 185 for the fir stand at Kwangnung. 3) The mode for the accumulation of organic carbon ($C_a$) is $c_a$= $610(1-e^{-0.185t})$), and for the decay of organic carbon (C) C = $610(1-e^{-0.185t})$. 4) The time required for the decay of half of the accumulated organic carbon in the fir stand is 3. 74 years and for 99% of elimination 27.02 years. 5) The litters of Abies holophylla killed by heat and washed with alcohol-benzol, with hot water, or with both alcohol-benzol and hot water were incubated after inoculated with suspension of firwood soil. Plate counts were made of fungi and bacteria from time to time. 6) Removal of the alcohol-benzol soluble substance stimulates at the beginning of the decay the growth of fungi and also of bacteria. 7) Removal of the water soluble fraction is detrimental to the growth of fungi in particular. 8) The distribution of soil microbial population is higher in both F and H horizon of the fir plantation soil in Kwangnung. However, the number of soil microorganisms decreases with the depth in forest soil.

• Korean Journal of Microbiology
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• v.6 no.3
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• pp.93-99
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• 1968

1) The aim of present investigation is to elucidate the relation of the balance of the production and decomposition of the fir litter. in Kwangnung plantation stands. 2) The decay constant, K, of litters was 0. 185 for the fir stand at Kwangnung. 3) The mode for the accumulation of organic carbon ($C_a$) is $c_a$= $610(1-e^{-0.185t})$), and for the decay of organic carbon (C) C = $610(1-e^{-0.185t})$. 4) The time required for the decay of half of the accumulated organic carbon in the fir stand is 3. 74 years and for 99% of elimination 27.02 years. 5) The litters of Abies holophylla killed by heat and washed with alcohol-benzol, with hot water, or with both alcohol-benzol and hot water were incubated after inoculated with suspension of firwood soil. Plate counts were made of fungi and bacteria from time to time. 6) Removal of the alcohol-benzol soluble substance stimulates at the beginning of the decay the growth of fungi and also of bacteria. 7) Removal of the water soluble fraction is detrimental to the growth of fungi in particular. 8) The distribution of soil microbial population is higher in both F and H horizon of the fir plantation soil in Kwangnung. However, the number of soil microorganisms decreases with the depth in forest soil.

• The Korean Journal of Ecology
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• v.9 no.3
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• pp.123-133
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• 1986

Black pine, Pinus thumbergii, stands in southwestern Korea were investigated. The black pine forest with 90 percent or more in the relative basal area (black pine basal area/whole pine basal area, RBA) was found in the coastal area. However, from the coastal area to the inland. RBA of the pine was decreased because the competition with red pine (P. densiflora) and/or pitch pine (P. rigida). In 25 year-old plants at the coastal areas, the wood volume of black pine is twofold or more than that of red pine, fourfold or more than that of pitch pine. The optimum rotation period for the maximum yield of black pine is estimated to take 35 years, based on the site index calculated. The optimal temperature for the pine plantation in Korean peninula should be the area in over 105。C.month in warmth index. And the soil conditions with 50% of RBA or over were 0.025%~0.151% of soil salinity, 3~6% of organic matter content, pH value 4.50~5.04, 8.5~11.0 me/100g of C.E.C..