• Journal of Korean Society of Forest Science
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• 제85권2호
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• pp.316-324
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• 1996

This study was conducted by relative time study to identify the allowance time and basic work time, which is together composed of the total work time, in the wage composition and work process composition. This study was done for the case of a basic one person a group from thinning treatment for some conifer species such as Japanese red pine, Japanese larch, pitch pine and Korean pine. 1. In order to apply the Japanese allowance time of four species to the general conifer case, the maximum value of allowance time composition value among those of four species was selected. The results are as follows: delay time for person 1.8%, rest time 14.1%, delay time for machine 12.5% and wating time 0.4%. The some of ratios of adjustment allowance time is 28.8%. 2. Estimated wage basis time table, which can be used for wage table or process table, was prepared by adding up adjusted general allowance time and standard work time estimated by estimation equation for each species through the time study.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.217-222
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• 2007

Since 1973, we attain a successful achievement of nation-wide afforestation such as a thick forest and heaped-up leaves. However, the higher of the formation density in forest, the more dangerous to be a large-scale forest fire whenever fire occurs. According to the type of forest in the country, 42% of the forest is occupied by conifer forest that are highly flammable, and the distribution of forest age is in a transition period from immature forest to mature one. And the structure is too weak to the forest fire for the occurrence and spread because there are too many scrub and shrub trees in the forest. As a matter of course, it is on the increase of the thinning-forest that can shift the forest structure from a weak on forest fire to a strong one nowaday. In other words, thinning-forest has primary purposes such as the promotion of producing forest trees, production of excellent timbers, and build-up of public forest area. Furthermore, in some reports, the reduction of ladder fuel by eliminating the vertical/horizontal fuel in a forest and ensuring spaces in the forest can decrease the occurrence of forest fire and the risk of spread of burning as by-effect. Therefore, this study is designed to clarify the relation with the risk of forest fire by an on-spat-investigation of the characteristics of forest composition on the thinning and the non-thinning area.

• Journal of The Geomorphological Association of Korea
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• 제17권2호
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• pp.53-61
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• 2010

In this study, pollen analysis and a dating were performed on the alluvial deposits in the Tangjeong Plains in Asan-Si, Chungcheongnam-Do. Specimens were collected at the altitude of about 12m, which belongs to the mid-forest belt in the cool temperate zone. The followings show the results. In general, the target zone passed through TJ-I (the coniferous forest age in which the Pinus forest was dominant), TJ-II (the mixed conifer and deciduous broad-leaved forest age in which Pinus and Quercus were dominant) and TJ-III (the coniferous forest age in which the Pinus was dominant) respectively. TJ-II was subdivided into TJ-IIa and TJ-IIb. TJ-I is presumed to be between about 2,810 and 1,500yrB.P.; TJ-IIa to be between about 1,500 and 1,370yrB.P.; and TJ-IIb to be between about 1,370 and 770yrB.P. As for TJ-III, it is presumed to begin after about 770yrB.P. In comparison with the nationwide pollen zone during the Postglacial, TJ-I and TJ-II are contrasted with the R-IIIa period and also TJ-III is contrasted with RIIIb (so-called human interference age). It is also presumed that Pinus luxuriated there after about 770yrB.P. as forests began to be markedly destroyed in the Tangjeong Plains.

• Journal of Forest and Environmental Science
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• 제26권3호
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• pp.219-223
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• 2010

It has long been recognized that wild vegetation are sort of improving fitness. Many peoples are now ingesting them instead of the vegetables that are grown in green house. In this regard, Parasenecio firmus, which is considered to be one of the rare species in Korea, has been given a lot of attentions as edible green plants recently. Hence it may be necessary to provide the information people who want to commercially cultivate the plants. Regarding appropriate forest stands that are fit for the cultivation. Firstly, we collected the seeds from 4 natural habitats to find out how many seeds are fully matured in the natural conditions. The quality of the seeds collected were found to be very low. However, it appeared as clear differences when screened seeds were grown in covered seed beds over winter. In this case the germination rate of the seeds was 95%, indicating that there may be no difficulty for mass production of plantlets. Secondly, in the field of planting test in an appropriate cultivating site among 6 of forest stands, those in Pinus koraiensis stand were the highest in survival rate, but somewhat low with those in Quercus mongolica and broad-leaved stands. Thus, it was demonstrated that forest stands dominated with conifer like P. koraiensis are more appropriate for the cultivation of P. firums.

• Journal of Korean Society of Forest Science
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• 제94권5호통권162호
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• pp.321-329
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• 2005

Based on the data representing four typical Korean pine forest types, the age structure, DBH distribution, species composition, and forking rule were systemically analyzed for old-growth Korean pine forest in Liangshui Nature Reserve, northeast China. The age structure of Korean pine trees was strongly uneven-aged with one dominated peak following normal distribution, and age of trees varied from 100 to 180 years within a stand. The DBH and height differences in same age class (20 years) varied from 28 cm~64 cm and 5 to 20 m, respectively. Many conifer and hard wood species, such as spruce, fir, costata birch, basswood, oak, and elm, were mixed with dominated trees of Korean pine. The canopy of the old-growth Korean pine forest can be divided into two layers, and differences of mean age and height between Layer I and Layer II were ranged 80~150 years and 7~13 m, respectively. The Weibull function was used to model the diameter distribution and performed well to describe size-class distribution either with a single peak in over-story canopy and inverse J-shape in under-story canopy for old-growth Korean pine stands. The forking height of Korean pine trees ranged from 16m to 24 m (mean 19.4 m) and tree age about 120 to 160 years old. The results will provide a scientific basis to protect and recover the ecosystem of natural old-growth Korean pine and also provide the model in management of Korean pine plantation.

• Journal of environmental and Sanitary engineering
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• 제21권4호
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• pp.39-48
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• 2006

In Juam basin, the ratio of non-point pollution source among pollutant loading of basin was significantly high, since the utilization level of land was high. In addition, the most pollutants were not treated and flowed out. In this study, the correlation between non-point source pollutants from the forest area and increasing algae was investigated. 1. Chl-a concentration flowed out to runoff from forest area and stream water was low as $0.1{\sim}20.3{\mu}g/{\ell}$ and $0.1{\sim}9.3{\mu}g/{\ell}$, respectively, and chl-a concentration ($0.1{\sim}28.5{\mu}g/{\ell}$) of branch stream was higher $5{\sim}7$ times than that of runoff from forest area. 2. In correlation between runoff from forest area and Juam lake water, annual chl-a concentration of area front Juam dam was higher twice than forest area. 3. In runoff from forest area within Juam basin, flagellate, green, diatom and blue algae occupied $33.0{\sim}41.7%$, $22.2{\sim}30.8%$, $17.3{\sim}22.5%$ and $13.7{\sim}17.6%$, respectively. 4. In runoff from forest area, both green and diatom algae were maintained constantly irrespectively of season, and flagellate algae dominated since August. 5. In characteristics by forest tree types, four types algae were inhabited in mixed forest, and flagellate algae were higher in conifer and broadleaf forest than in other area. And green algae in herbaceous forest were higher than other area.

• The Plant Pathology Journal
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• 제28권3호
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• pp.311-316
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• 2012

Fusarium root disease can be a serious problem in forest and conservation nurseries in the western United States. Fusarium inoculum is commonly found in most container and bareroot nurseries on healthy and diseased seedlings, in nursery soils, and on conifer seeds. Fusarium spp. within the F. oxysporum species complex have been recognized as pathogens for more than a century, but attempts to distinguish virulence by correlating morphological characteristics with results of pathogenicity tests were unsuccessful. Recent molecular characterization and pathogenicity tests, however, revealed that selected isolates of F. oxysporum are benign on Douglas-fir (Pseudotsuga menziesii) seedlings. Other morphologically indistinguishable isolates, which can be virulent, were identified as F. commune, a recently described species. In a replicated greenhouse study, inoculating Douglas-fir seedlings with one isolate of F. oxysporum prevented expression of disease caused by a virulent isolate of F. commune. Moreover, seedling survival and growth was unaffected by the presence of the F. oxysporum isolate, and this isolate yielded better biological control than a commercial formulation of Bacillus subtilis. These results demonstrate that an isolate of nonpathogenic F. oxysporum can effectively reduce Fusarium root disease of Douglas-fir caused by F. commune under nursery settings, and this biological control approach has potential for further development.

• Asian Journal of Turfgrass Science
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• 제10권1호
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• pp.71-80
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• 1996

Fourteen dictyostelids(12 species of genus Dictyostelium. 2 species of genus Polysphonylium) oc-curred in Mt. Chiri Korea. Soils samples were collected from the nine sites. In the broadleaved-deciduous forests and conifers, common species of cellular slime molds are Dictyostelium mucoroides, and D. brefeldianum. Only two species are above 30 in importance value and above 50% in presence. Dominant species in the broadleaved-deciduous forests is D. mecoroides wheras in the conifer forests is D. brefeldianum which was not common until now in Korea, found in the low elevation either. In addition, Five cellular slime molds occured in the Miscanthus sinensis community: 4 species of genus Dictyostelium and 1 species of genus Polysphonylium. Dominant species is D. purpureum. Importance value is very high, 85. This Result is exceptively unusual. It dind't occur in the other sites. Correlation between the altitudes and the occurrence and distribution of dictyostelids was not accurate. Merely dominant species were different according to forest types and organic matter contents in soil. Cellular slime molds have different favorite forest types. And the growth and germination are dependent on the soil enviroryrnental conditions and soil quility. Key words:Dictyostelids, Mt. Chiri D. mecoroides, D. brefeldianum. D. purpureum. Soil quility, Favorite forest type, Soil environmental condition.

• Proceedings of the KSRS Conference
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• 대한원격탐사학회 2006년도 춘계학술대회 논문집
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• pp.267-270
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• 2006

본 논문은 국산 고해상도 위성화상의 활용 일환으로 산불피해림의 정밀정성정보를 제공하기 위한 낙엽송 및 리기다 소나무의 산불피해등급 육안판독열쇠에 관한 연구이다. 본 육안 판독열쇠는 낙엽송과 리기다 소나무의 산불피해등급 판별을 위해 4가지 요소, 즉 색, 형태, 구조 그리고 질감에 기초로 개발하였다.

• Current Research on Agriculture and Life Sciences
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• 제2권
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• pp.42-55
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• 1984

The direction of scientific researches on tree improvement and forest management in several universities and research institutes in Japan can be summarized as follows: They put a great emphasis on sugi, Cryptomeria japonica and cypress, Chamaecyparus oblusa which are two major conifer species largerly planted in the Japanese forestry. In the research of sugi, a great concern has been made in evaluating inheritance of forest tree, quantitative characters and genetic parameter of growth, and in breeding for resistance to diseases and insects and to all the natural calamities. Interaction between environmental conditions and genetic nature of tree can be concerned factors in relation with forest damage, together with silvicultural conditions and pest infestation. Selfing hybrids of $F_1$ made from crossing twisted-leaf sugi, defomity leaf type and midori sugi, normal leaf type segregated the normal needle, twisted needle, green leaf and albino leaf type. It seemed that separation of many defomity individuals can be governed by two dominant complementary genes and from the near loci of which it was detected lethal genes. 52% of Japanese forestry is occupied by the small forest landowners like Korean forestry. This made difficulty for forest improvement such as progressive afforestation and for capital accumulation form forestry. The Forest Corporation was established at first in 1959 to aming at productive forestry structure and forest management, and afforestation. For these purpose, 35 Forest Corporations are at moment operating throughout Japan. However, investment in forestry business becomes less attractive since the wage in forest production duction increased in higher trend. than timber price. Therefore, an artifical afforestation becomes yearly decreased. At present. the self-sufficient rate of timber production in Japan is about 35%, and so a great effort is being made to increase self-sufficient rate of timber production.