• Current Research on Agriculture and Life Sciences
• /
• v.19
• /
• pp.31-37
• /
• 2001

Uyeki(1928) classified Pinus densiflora into six ecotypes(Northeastem type, Middle-southern flat type, middle-southern upland type, Wibong type, Ankang type, and Geumgang type) based on the pine tree type. The bark color of Geumgang type was ash-brown color on the lower parts of stem and yellowed color on the upper parts of stem. We investigated the physicochemical properties of soil forests to obtain basic data for preservation of exellent pine (Pinus densiflora for. erecta Uyeki). The results were as follows; The soil texture of the Pinus densiflora for. erecta Uyeki forests were showed nearly as sandy loam, that is, sand, silt and clay were consisted of 72%, 15% and 13%, respectively. Soil acidity(pH 4.6) was lower than Korea average forest soil acidity(pH 5.2). The average contents of available phosphate was 11.7ppm at Sokwang-ri, 26.8ppm at Mt. Eungbong, 24.2ppm at Mt. Kumma. It was the lowest at Uljin(4.6ppm). The contents of carbon was 6.2% at Mt. Chungok, 6.1% at Mt. Eungbong. This value was more than average of Korea forest soil.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.52 no.3
• /
• pp.1-7
• /
• 2010

The ichthyofauna and passing efficiency of fishways were surveyed in Geumgang estuary from May to October in 2009. The fishes collected were classified into 24 species, 23 genera belonging to 8 families. These 24 species consist of 17 freshwater fish species, 3 migration fish species and 4 peripheral freshwater fish species. Seasonal function of fishways showed the migration from May to June and returning to the reservoir of fishes be washed out to sea when sluice gate open by rainfall in July and August. Most of the fishes catched in fishways moved from middle tide to high tide except for July. Fishes ascended fishways between the middle ebb tide and the ebb tide only July, because small freshwater swim against the fishway for leaching the reservoir through the newly formed flow when the water level at the fishway kept dropping. Small fishes that body length less than 200 mm mainly used gabion type fishways and fishes over 200 mm utilized a cascade type fishways. Based on the total individuals collected, the efficiency of the fishway was 1 % for the anadromous fish and over 80 % for freshwater fish. Therefore, it is concluded that ecological function of the fishway in the Geumgang estuary dike be very important not only for fish migration but also freshwater fishes's returning.

• Journal of People, Plants, and Environment
• /
• v.23 no.3
• /
• pp.293-304
• /
• 2020

Background and objective: This study was carried out to assess the relationship between the internal and external environments and the ecological items in five sites with a high level of artificial use intensity prior to the establishment of Geumgang River riparian ecological belts. Methods: The sites were classified into forest type, cultivated land type and urbanized type in accordance with their respective locational types. Ecological items including plant ecology such as proportion, naturalization index and urbanization index of native species were analyzed and animal ecology such as the number of species and population of wild birds, amphibians and reptiles, mammals, and butterflies and dragonflies, which are indicator insects, were investigated. In addition, species diversity indices of wild birds, butterflies and dragonflies found in all the subject lands were computed. Results: Among the plant ecological items, the ratio of native species in the forest type was higher than 90%, which was a satisfactory level, while the naturalization and urbanization indices were less than 10%. The number of species in the animal ecological characteristics was reduced in the order of forest type, cultivated land type and urbanized type. As the results of correlation analysis, the internal area of the planted area showed a negative correlation with the total of individuals. The area of grasslands showed a positive correlation with the number of dragonfly species and the total number of individuals, thereby illustrating that wet grasslands have positive effects. The area of surrounding forests, as an external environment, had a negative correlation with the urbanization index (UI) but a positive correlation with the inhabitation of butterflies and the total number of species. Conclusion: The results confirmed the need for more diversified special compositions including planted land, grassland, wetland, bodies of water and waterways within the subject land in the wetland ecological belt along with the need for surrounding forest location and preservation from the perspective of purchase and restoration of land for enhancement of wider biodiversity in the future.

• Journal of Microbiology
• /
• v.40 no.4
• /
• pp.335-339
• /
• 2002

Partial sequences of 16S rRNA gene of five chroococcalian blue-green algal strains, Aphanothece nidulans KCTC AG10041, Aphanothece naegelii KCTC AG10042, Microcystis aeruginosa KCTC AG10159, Microcystis ichthyoblabe KCTC AG10160, and Microcystis viridis KCTC AG10198, which were isolated from water from the Geumgang River, were determined and were inferred their phylogenetic and taxonomic positions among taxa of order Chroococcales. Most taxa of Chroococcales whose partial 16S rRNA gene sequences were aligned in this study, are clustered with other related taxa. Aphanothece nidulans KCTC AG10041 and Aphanothece naegelii KCTC AG10042 made a cluster with other European species of these genera, which supported 100% of the bootstrap trees with a very high sequence similarity (97.4-99.4%) in this study. Three strains, Microcystis aeruginosa KCTC AG10159, M. ichthyoblabe KCTC AG10160, and M. viridis KCTC AG10198, formed a cluster with other Microcystis spp. supported 100 % of the bootstrap trees with a similarity of 97.0-99.9% except for two strains. However, this phylogentic tree made no resolution among the species of Microcystis spp. The topology of the tree reconfirmed the taxonomic status of three species of Microcystis, identified in this study based on the morphology, as three colonial types of Microcystis aeruginosa com. nov. Otsuka et al. (1999c). The genera of chroococcalian cyanophytes are heterogeneously clustered in these sequence analyses. We suggest that more molecular studies on the genera of Chroococcales with reference strains, widely collected from restricted geographic or environmental ranges, get accurate taxonomic or phylogenetic determinations.

• Journal of Korean Society of Forest Science
• /
• v.94 no.6
• /
• pp.441-445
• /
• 2005

Researches on estimating national-scaled forest biomass are being carried out to quantify the carbon stock of forests with the Kyoto Protocol. In general, estimates of national-scaled forest biomass are based on forest inventory data which provides estimates of forest area, stem volume, and growth of stem by age classes. Estimates of forest biomass are, however, obtained by converting stem volumes to dry weight with stem density and thereafter to whole tree biomass with biomass expansion factors (ratios of whole tree dry weight to stem dry weight). Pinus densiflora is widely distributed and one of the most economically important timber species in Korea. The species are largely grouped into two ecotypes of Geumgang and Jungbu. Stems of Geumgang type trees are straight and high compared to those of Jungbu type trees. The objective of this study was to determine and compare stem density and biomass expansion factors fore two ecotypes of Pinus densiflora according to stand age. Stem density of both ecotypes of Pinus densora increased and biomass expansion factors of them decreased with increasing tree age. In he same age class, stem density and biomass expansion factor of Geungang type Pinus densiflora were lower than those of Jungbu type Pinus densiflora. There were statistically significant differences in stem density and biomass expansion factors between Geumgang type and Jungbu type Pinus densiflora in 0-20-year-old stands and 40-60-year-old stands. Our results suggested that the reliability of the national forest biomass inventory could be improved by applying the ecotype- and age-dependent stem density and biomass expansion factors.

• Journal of People, Plants, and Environment
• /
• v.24 no.4
• /
• pp.389-401
• /
• 2021

Background and objective: The purpose of this study is to investigate the ecological status of six areas around Geumgang River that used to be farmlands before they were restored as a riverine ecobelt. This study aims to analyze the correlation between the location environment and ecological status of the sites to identify the environmental factors affecting them. Methods: The sites are classified into four types according to restoration: terraced paddy fields, flat paddy fields, artificial wetland, and landscape forest. The survey items were divided into land use status, plant ecology, and animal ecology. Results: In terms of plant ecology, terraced paddy fields showed favorable naturality with the rate of native species above 90% and the naturalization index below 10%. In terms of animal ecology, the total number of species found in these areas was biggest in terraced paddy fields, followed by flat paddy fields, artificial wetland, and landscape forest. Regarding species diversity, terraced paddy fields also showed abundant species with an average of 1.05 to 1.09. The results of the correlation analysis showed that the forest area around the sites had the most significant effect on species diversity. The grassland and open water area showed a positive correlation with the total number of animal species and the number of dragonflies, confirming that the marshy grassland had a positive effect. As the cultivated land and urbanized area around the sites increased, it had a negative effect on the distribution of native species and the number of animal species that appeared, and a positive effect on the naturalization index. Conclusion: It is necessary to establish preemption and restoration plans for sites such as grasslands adjacent to the forest and terraced paddy fields in order to promote resilience of the diverse species returning to the purchased lands.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2004.03b
• /
• pp.274-281
• /
• 2004

In this paper, the existing Stokoe type torsional shear equipment is modified to saturate the specimen and measure excess pore water pressure during undrained testing. Two types of sands, Geumgang and Toyoura sands, were collected and TS tests were performed at various densities drainage conditions, and confining pressures. The cyclic threshold shearing strains were estimated based on the variations of shear modulus, material damping ratio and pore pressures with loading cycles. The effects of relative density, confining pressure, and drainage condition on the cyclic threshold shearing strains were investigated.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.50 no.1
• /
• pp.1-19
• /
• 2022

The Geumgang Pine (Pinus densiflora) Forest in Sogwang-ri, Uljin has traditionally been a pine tree protection area (prohibited forest) for timber production purposes, and is now designated and managed as a protected area for forest genetic resource conservation by the Korea Forest Service. This study, we analyzed topographical characteristics, existing vegetation, tree age, and plant community structure, and proposed a sustainable management method for the Geumgang Pine (Pinus densiflora) Forest in Sogwang-ri, Uljin for timber havesting purposes. The topographical characteristics of the target area were 36.7% ridges and 38.7% valleys; the ratio of ridges to valleys was similar, and the slopes formed 24.7% of the total area. The types of pine forest communities are divided into six types based on the progress of pine forest renewal, the competition with other species such as deciduous broadleaf trees, and the formation of layered structures. It has been confirmed that the age of the large-diameter pine trees (40~60cm in diameter) is approximately 60~70 years, which is relatively low. As a result of the analysis of the relative importance percentage and layered structure, differences depended on the progress of the pine forest renewal project, and not only the maintenance of the pine forest, but also the creation of a secondary growth forest, the density adjustment of pine trees, and the active management of competitive trees. The average basal area by the community was 12,642.1~25,424.4cm² for the tree layer and 1.8~1,956.5cm² for the low tree layer based on a quadrat of 400m². The difference in the basal area appeared to depend on the size and number of trees forming the tree layer and the degree of pine forest renewal (the degree of time elapsed after thinning pine trees). The average number of species that appeared in each community was 8.7-20.3; there were many species located in valleys, and the type competes with deciduous broadleaf trees due to the lack of management. The diversity of species ranged from 0.6915-1.0942, and was evaluated as low compared to pine communities in central temperate zones. In this paper, we determined the management goals of Geumgang Pine (Pinus densiflora) Forest in Sogwang-ri, Uljin to produce timber with high economic value, and suggested efficient vegetation management for continuous afforestation, the establishment of a timber production system, and improvement of wood production as a management direction.

• Korean Journal of Heritage: History & Science
• /
• v.38
• /
• pp.129-156
• /
• 2005

Increasing discovery cases of underground storage facilities made of earth, wood, or stone are being reported from the recent excavation survey of the Baekje relics. Accordingly, the purpose of this study is to examine the structure and function of the underground storage facilities of Baekje following a classification made by the type and building method as follows: plask shape, wooden box shape, and stone box shape. The plask shape storage is the most representative underground storage of Baekje that has been found in numerous relics more than 600 sets around Hangang(Han River) and Geumgang(Geum River) from the Hansung period to Sabi period in Baekje Dynasty. It is a historical artefact as a part of the unique storage culture of Baekje around Hangang and Geumgang from the 3rd to 7th Century. Considering its structure and the example of Chinese one, it might had been used for a long-term storage of grains and various other items including earth wares. The storage facility in wooden box shape and stone box shape are found mostly in the relics Of Sabi period. Thus it might had taken some functions of the storage in traditional pouch shape which had decreased after the 6th Century. In particular, the wooden box shape and stone box shape storage required enormous labor force to build owing to their structure and building method. Thus, they were considered to had been used for official purposes in province fortress and citadel artefact. The wooden box shape storage facility is classified into flat rectangular type and square type based on the structure, and into Gagu type(架構式) and Juheol type(柱穴式) based on the building method. It might had been decided according to the geography and geological feature of the place where the storage was to be built. Considering the examples of Gwanbuk-ri relics and Weolpyong-dong relics, the wooden box shape storage facility might had been used for various items depending on the needs, including foods such as fruits and essential provisions at the military base. Considering the long-term food storage, the examples in Japan, and the functional characteristics of the underground storage facility, there is a possibility that the wooden and stone box shape storage facilities had been built so as to safely store important items in case of fire. This study is only a rudimentary examination for the storage facility in Baekje. Thus further studies are to be made specifically and comprehensively on the comparison with other regions, distribution pattern, discovered relics and artefacts, and functions.

• Journal of the Korean association of regional geographers
• /
• v.14 no.1
• /
• pp.27-39
• /
• 2008

The propose of this research paper is to clarify the formative process of the lake-like swamps formed in channels of Nakdong-gang river and its tributary, Gumho-gang river. In order to understand the formative process of lake-like swamps, I compared topographical maps of three years(1918, 1962, 2005), analyzed the outline change of swamps, and draw their cross-sectional view and analyzed the horizontal distribution of particle size. Results of analysis are as follow. First, Saegang swamp and Geumgang swamps are residual swamps which are formed in abandoned distributary channels of braided reach. In braided reach, tributaries wind freely to create a new channel or to eliminate a old channel. Second, the Ssiksil swamp and Nat swamp are yazoo-type swamps. Their stream channels run parallel to the natural levees, as it blocks the waterway of a effluent tributary flowing from backward mountains to main stream. Third, the Secheon, Hochon and Jinchon swamps are backswamp behind natural levee. As main stream overflows, natural levee and back swamp are formed. Later flowing water of next bigger flood enter through natural levee into backswamp, create a channel following backswamp.