• Journal of the Korean earth science society
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• v.26 no.7
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• pp.661-667
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• 2005

It was preliminarily considered that Jangdo wetland was a concave landform formed by the weathering of granite intruding Precambrian silicified metasedimentary rocks. Various granite-weathered topography was observed. The formation scenario of Jangdo wetland is as follows. By flood or slope mass movement of regolith, rock fragments were moved to form a low-relief slope landform. As a result, wetland was formed. By analyzing the slope soil and wetland sediment, we conjectured that Jangdo wetland depended on the influence of peripheral slope soil. In these concavelandform environment, the supply of water and organic materials was sustained for a long time to form a organicnondegradable wetland environment. In addition, the plants appropriate to this wetland environment were settled to thicken the wetland. This is how the present Jangdo wetland was thought to be formed.

• Mycobiology
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• v.48 no.5
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• pp.351-363
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• 2020

Here, we investigated fungal microbiota in the understory root layer of representative well-conserved geographically segregated natural wetlands in the Korean Peninsula. We obtained 574,143 quality fungal sequences in total from soil samples in three wetlands, which were classified into 563 operational taxonomic units (OTU), 5 phyla, 84 genera. Soil texture, total nitrogen, organic carbon, pH, and electrical conductivity of soil were variable between geographical sites. We found significant differences in fungal phyla distribution and ratio, as well as genera variation and richness between the wetlands. Diversity was greater in the Jangdo islands wetland than in the other sites (Chao richness/Shannon/Simpson's for wetland of the Jangdo islands: 283/6.45/0.97 > wetland of the Mt. Gariwang primeval forest: 169/1.17/0.22 > wetland of the Hanbando geology: 145/4.85/0.91), and this variance corresponded to the confirmed number of fungal genera or OTUs (wetlands of Jangdo islands: 42/283> of Mt. Gariwang primeval forest: 32/169> of the Hanbando geology: 25/145). To assess the uniqueness of the understory root layer fungus taxa, we analyzed fungal genera distribution. We found that the percentage of fungal genera common to two or three wetland sites was relatively low at 32.3%, while fungal genera unique to each wetland site was 67.7% of the total number of identified fungal species. The Jangdo island wetland had higher fungal diversity than did the other sites and showed the highest level of uniqueness among fungal genera (Is. Jangdo wetland: 34.5% > wetland of Mt. Gariwang primeval forest: 28.6% > wetland of the Hanbando geology: 16.7%).

• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.63-74
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• 2015

The purpose of this study is to provide the basis information for ecological conservation and restoration of Jangdo wetland conservation area through the survey of vegetation diversity and spatial distribution characteristics. Syntaxonomic account of plant communities were carried out field survey by Z.-M. school method at 14 sites and relationship analysis between plant community and environment variables with Principal Coordinate Analysis (PCoA). Based on the floristic composition, all the plots were classified into xeric and hydric type and arranged in seven plant communities. Spatial distribution of plant communities is determined primarily by the soil moisture condition and amount of organic matter. Hydric vegetation is around 8% ($7,337m^2$) of the protected area and distributed swamp forest of dominating willows under 18 years. Proliferation of willows are recognised extended from edge to centre after in 1990's caused by fallow and control of livestock grazing on wetland. Jangdo wetland will have to readjust the protection boundary because wet meadow zone and swamp forest have been distributed outside the protection area.

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.512-527
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• 2012

Jangdo Island (area $1.54km^2$) located in the western end of Dadohae Haesang National Park has been recognized as an prominent ecoregion possessing high moor and national biodiversity hotspot. In terms of the Z$\ddot{u}$rich-Montpellier School's phytosociology, we investigate the diversity of plant communities on the island and reevaluate the Jangdo wetland designated as Ramsar site. Ten physiognomic types of the Jangdo's vegetation were classified into 22 syntaxa (3 associations, 15 communities and 4 subcommunities). Jangdo wetland was actually denominated as 'eutrophic wetland' by Pharagmitetea and Orizetea rather than 'high moor'. Nevertheless, existence value of the Jangdo wetland is evaluated very high as a stepping stone for migratory birds and even plant dispersions. A new site of the northernmost distribution of Arachniodo-Castanopsietum sieboldii, which is a kind of cold-resistant phytocoenosis among the Camellietea japonicae of the warm-temperate broad-leaved forests, was described. Hosta yingeri-Carpinus turczaninovii var. coreana community and Carex wahuensis var. robusta-Juniperus chinensis var. procumbens community were described specifically as an endemic and an edaphic vegetation type, respectively. The unique Jangdo's vegetation reflects regional environmental conditions such as much higher frequency of frost-free days and the highest number of annual average foggy days in Korea and a well-developed aquifer in the depressed basin formed by differential erosion. We identified that human interventions (pasture, logging, forest fire, cultivation, etc.) has been involved intensively on every vegetation types, even though a rugged and inaccessible topography of the island. Particularly the Jangdo wetland has been recently threatened by fundamental distortion on hydrological system. We request an immediate establishment of the conservation prescription manual.

• Journal of The Geomorphological Association of Korea
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• v.17 no.2
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• pp.63-76
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• 2010

The Jangdo wetland is located on a very gentle slope of the mountain area in Daejangdo island, Shinan-gun, Korea, in which the area of the watershed is estimated at 147,000 m². The wetland has been regarded as a peat bog without any sedimentological evidence. This study was conducted to analyze the geomorphological and sedimentological characteristics of the wetland. The geographic information system (GIS) was used to analyze the drainage system, and field surveys were conducted to measure the range and depth of wetland deposits. The grain size analysis, organic matter determination, elements analysis and radiocarbon dating were performed on samples from the wetland. As a result, the wetland deposits were about 30 cm deep on average, the mean grain sizes ranged from 50 to 500 μm, and the average C/N ratio was 11.5. The portion of organic matter it contained was only 5~26%, which did not satisfy the peat standards. The radiocarbon ages from the wetland deposits range 180±50 ¹⁴C yr BP to modern, which indicated that natural and anthropogenic interferences including agricultural activities have continuously happened. We conclude that the Jangdo wetland is still in its infancy, not a steady state, so that it could be very sensitive to a small disturbance.

• Korean Journal of Environment and Ecology
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• v.20 no.4
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• pp.407-414
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• 2006

This study was carried out to investigate soil properties, ordination, and vegetation of a forest wetland in Jangdo, Sinan-Gun. Peculiar species such as Epilobium pyrricholophum and Lycopus ramosissim us were found in the forest wetland of Jangdo, and Hosta yingeri and Carpinus turczaninovii for coreana that are an endemic species of Korea were also found. The vascular plants of 40 families 62 genera 57 species 9 varieties 1 form, total 67 taxa were accounted for. The communities were classified as Salix koreensis-Isachne globosa community, Isachne globosa community, and Miscathus sinensis var purpurascens community. Soil organic matter, total nitrogen, available phosphorous concentrations, and cation exchange capacity each ranged from 20.6 to 72.4%, 0.74 to 2.13%, 33.3 to 114.6 ppm, and 25.5 to 94.3 me/100g, respectively. Soil pH ranged from 5.10 to 5.42. Soil texture was clay loam. Results of the correlation between Jangdo forest community and environmental factor are as follows; Soil pH was the most effective factor for plant community distribution. The Salix koreensis-Isachne globosa community was found where it had the highest soil organic matter, nitrogen, and exchangeable Na, Ca, Mg concentration, ana CEC among the three communities. Miscathus sinensis var. purpurascens community was found where it had the lowest soil organic matter, nitrogen, and exchangeable Na, Ca, Mg concentration, and CEC among the three plant communities.

• Journal of the Korean Geographical Society
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• v.49 no.2
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• pp.221-244
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• 2014

We suggested several implications by examining geochemical properties of sediments in Simjeok, Jangdo, and Hwaeomneup mountain wetlands which are natural preservation areas. Geochemical properties of wetland sediments show that all wetlands were included in the type of fens, but their distribution patterns were different from one another. We classified three sub-groups of sediments using the two step cluster analysis on the ratio of exchangeable cations. Wetland sediments can be grouped into Ca-dominated, Mg-dominated, and K-dominated types. Simjeok wetland have Ca-dominated sediments, while the sediments of Jangdo wetland indicate the Mg-dominated and Ca-dominated characteristics. Hwaeomneup wetland is composed of K-dominated sediment mainly. Different properties in the ratio are affected by various environmental factors such as geological, pedological, and vegetational settings. Because these geochemical properties will be affected by climate change and human impacts, these will be environmental indicator in mountain wetlands and be used in wetland management. This scheme can be used for classification of mountain wetlands. Therefore, we should work on geochemical properties of wetland sediments and classification schemes based on geochemical properties not only to widen understanding in geomorphic system or ecosystem of mountain wetlands but to conserve mountain wetlands properly.

• Korean Journal of Environmental Biology
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• v.37 no.1
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• pp.109-118
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• 2019

This study was carried out to investigate the vegetation of wetland and terrestrial lands in Jangdo wetland conserved area in Korea and to analyze the characteristics of the vegetation changes in the recent years. From the plant community, there were evergreen broad-leaved forests of the Machilus thunbergii, Castanopsis cuspidata, and Machilus thunbergii-Castanopsis cuspidata communities. Moreover, there were deciduous broad-leaved forests of the Salix koreensis, Mallotus japonicus, Mallotus japonicus-Pueraria thunbergiana and Celtis sinensis communities. Additionally, there were shrub forests of the Rosa multiflora-Rubus hirsutus, grassland of Molinia japonica-Miscanthus sacchariflorus and Miscanthus sacchariflorus-Imperata cylindrica communities, and plantation forest of the Pseudosasa japonica community. The area of the wetland vegetation (15%) was much narrower than that of the terrestrial land vegetation (85%). Comparing these results with those of the past 10 years, the wetland plant communities decreased by one-third and the proportion of neutral or dry plant communities increased. In order to mitigate landization succession of the wetland and maintain native wetland vegetation in this area, the expansion of the Salix koreensis community must be controlled to a suitable scale. In addition, it is urgently required to remove the invasive non-wetland plants, such as Pseudosasa japonica and Pueraria thunbergiana.