• Economic and Environmental Geology
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• v.52 no.1
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• pp.49-64
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• 2019

SHRIMP U-Pb ages were analyzed for the detrital zircons separated from the Jangsan Formation of the Lower Paleozoic Joseon Supergroup in the Taebaeksan Basin and the Mungyeong area. Similar to the previously reported from Taebaeksan basin, the detrital zircons show strong peaks near the age of about 1.8-2.0 Ga and about 2.5 Ga. This indicates that the detrital zircons of the Jangsan Formation originated from the basement rocks of the Korean Peninsula. Although the age of the basement rocks on the Korean Peninsula is mainly concentrated in the 1.8-2.0 Ga, the age of about 2.5 Ga is clearly visible in the Jangsan Formation, suggesting that the age distribution of the basement rocks exposed to the surface at that time may be somewhat different from now. The detrital zircons of age-unknown Geumsusan Formation distributed between Danyang and Jecheon also show the U-Pb age distribution with a strong peaks around 1.8-2.0 Ga and 2.5 Ga, which is very similar to that of the Jangsan Formation, suggesting a possibility that the two formations are likely to be correlated.

• Korean Journal of Ecology and Environment
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• v.48 no.2
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• pp.129-138
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• 2015

Forest vegetation of Geumsusan (1,016.0 m) and Doraksan (964.4 m) in Woraksan National Park is classified into mountain forest vegetation. Mountain forest vegetation is subdivided into deciduous broad-leaved forest, mountain valley forest, coniferous forest, riparian forest, afforestation and other vegetation. Including 77 communities of mountain forest vegetation and 5 communities of other vegetation, the total of 82 communities were researched; mountain forest vegetation classified by physiognomy classification are 37 communities deciduous broad-leaved forest, 16 communities of mountain valley forest, 8 communities of coniferous forests, 1 community of riparian forest, 15 afforestation and 5 other vegetation. As for the distribution rate for surveyed main communities, Quercus variabilis and Quercus mongolica communities account for 33.031 percent of deciduous broadleaved forest, Cornus controversa community takes up 29.142 percent of mountain valley forest, Pinus densiflora community holds 64.477 percent of mountain coniferous forest holds. In conclusion, minority species consisting of Quercus variabilis, Quercus mongolica, Pinus densiflora, Quercus serrata and Cornus controversa are distributed as dominant species of the uppermost part in a forest vegetation region in Woraksan National Park. In addition, because of vegetation succession and climate factors, numerous colonies formed by the two species are expected to be replaced by Quercus variabilis, Quercus mongolica, Cornus controversa and Fraxinus mandshurica which are climax species in the area.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.202-219
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• 2017

The purpose of this study was to analyze the community structure of forest vegetation in Mt. Geumsusan belong to Woraksan National Park for providing basic information of ecological management. Data were collected by 41 plots from June to November in 2016 using Z-M phytosociology method, which was analyzed with vegetation types, mean importance value and coincidence method. As the results, the forest vegetation was classified into Quercus mongolica community group including Cornus controversa community, Castanea crenata community(Vegetation unit 3), Quercus variabilis community(Vegetation unit 4) and Q. mongolica community(Vegetation unit 5). C. controversa community was divided into two groups such as Ulmus davidiana var. japonica group(Vegetation unit 1) and Parthenocissus tricuspidata group(Vegetation unit 2). Mean importance percentage of vegetation unit 1 was showing Fraxinus rhynchophylla 14.9%, Morus bombycis 8.7% and Acer pictum subsp. mono 8.3%, that of unit 2 was Larix kaempferi 23.2%, C. controversa 20.1% and P. tricuspidata 6.5%, that of unit 3 was Q. mongolica 15.8%, C. crenata 13.4% and F. rhynchophylla 9.8%, that of unit 4 was Q. mongolica 26.6%, Q. variabilis 20.8% and Pinus densiflora 16.7%, that of unit 5 was Q. mongolica 48.3%, Styrax obassia 7.5%, F. rhynchophylla 5.3% in the order, respectively. Each vegetation unit was classified with dependance on environmental factors as 700m of altitude, $20^{\circ}$ of slope degree, middle slope of topography, 20% of bare rock, 30 taxa of present species, 80% of tree layer coverage rate and 20m of tree layer height. In conclusion, it was preferentially considered that development of peculiar and specific management methods with vegetation unit classified above should be needed for ecological and sustainable forest vegetation management.