• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1489-1495
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• 2020

Gotjawal, Jeju Island, Korea is a lava-formed forest with low soil content that is unique in the world. Around 6 percent of the Jeju Iand is classified as a lava-based specific forest. The forest has been gradually disappearing during the last several decades, with approximately one half having been destroyed. Our study undertakes a detailed analysis of the landscape of the lava subsidence, and describes the fungi, vegetation, and soils of Cheongsu Gotjawal. Soil samples from the Gotjawal were collected, and soil analyses as well as pyrosequencing of the internal transcribed spacer gene for fungal communities were performed. Soil fungal communities are represented by Discisedars, Fusarium, Pleochaeta, and Fuscoporia genera. Endemic vegetation of the Gotjawal includes the plants Pleris critical, Machilus japonica, Quercus glauca, Arachniodes aristata, and Neocheiropteris ensata. Results of soil analysis indicate sandy loam with 31.70% organic matter, and 1.36 mg/kg of total nitrogen. This fundamental information can help understand the invaluable and unique nature of Cheongsu Gotjawal, and the necessity for more studies on Gotjawal.

• Korean Journal of Plant Taxonomy
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• v.49 no.3
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• pp.215-223
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• 2019

Recently, it has become known that Gotjawal terrain is an important area, therefore the study on this area has conducted in the geological, ecological, and cultural aspects. The studies on bryophytes of Gotjawal, however, have not been sufficiently performed. This study presents a survey on the bryophytes of the evergreen broad-leaved forest of Cheongsu-ri at Hangyeong Gotjawal in the southwestern part of Jejudo Island, Korea. A total of 72 taxa belonging to the Bryophyta (18 families 43 genera 55 species) and Marchantiophyta (11 families 13 genera 17 species) were determined and the liverwort index was 23.6%. Predominant life-form was weft. The rates of the bryophytes dominating in mesic to hygric sites were higher than the bryophytes mainly observed in xeric habitats. These values indicate that the forests are widespread and dense in this study area. Upon an investigation of the substrates, the bryophytes on rocks were most diverse. The results appear to stem from the fact that volcanic rock masses of various sizes lay scattered over the study area, offering numerous micro-habitats for bryophyte due to one of the characteristics of Gotjawal. We suggest that more detailed studies should be conducted at the regional scale to establish the bryophyte flora of Gotjawal and the evergreen broad-leaved forests on Jejudo Island.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.2
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• pp.136-143
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• 2015

Gotjawal areas have the unique ecosystem and we need to approach as the inhabit of animals to conserve Gotjawal. This study was conducted in Hangyeong-myeon Cheongsu-ri located in the western part of Jeju Island belonging to Hangyeong Andeok Gotjawal Zone and Jocheon-eup Seonheul-ri located in the eastern part of Jeju Island belonging to Jocheon Hamdeok Gotjawal Zone. Survey on advent of the birds was done twice a month from February 2013 to December 2014. A total of 66 species and 4,140 individuals in two Gotjawals were observed during the survey period. In Seonheul Gotjawal area, 53 species and 1,907 individuals were observed while it was 49 species and 2,233 individuals in Cheongsu Gotjawal area. The number of species between two Gotjawal areas was not significantly different, but the number of individuals between two Gotjawal areas was significantly different. Thirty-six species were found in both Gotjawal areas as common species and the index of similarity was 0.7. A total of 23 species were classified as the residents, 15 species as the winter visitors, 16 species as the passage migrants, 11 species as the summer visitors, and 2 species as the vagrant. Twelve species as legally protected birds including the natural monument and the endangered species were found and 8 species were found in Seonheul Gotjawal area while it was 10 species in Cheongsu Gotjawal area. The species that directly using a wetland or food resources related to water were 12 in the Seonheul and 6 species were observed in the Cheongsu Gotjawal area, but there is no significant difference between two Gotjawal areas. However, the number of individuals in Seonheul Gotjawal area was significantly higher than in that of in Cheongsu Gotjawal area. We need to research the wetlands and micro climatic condition existing in Gotjawal forests to find the cause of difference of two areas and this difference must be considered as an important indicator for the protection of Gotjawal forests.

• Journal of Environmental Science International
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• v.31 no.12
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• pp.1013-1025
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• 2022

This study was carried out to analyze water cycle characteristics and evaluate water retention function in Jeju Gotjawal forest from 2013 to 2017. The average ratio of throughfall, stemflow, interception loss in Seonhul Gotjawal (SH) and Cheongsu Gotjawal (CS) was 43.1%, 15.8%, and 41.1%, respectively. Rainfall-throughfall, rainfall-stemflow, and rainfall-interception loss were expressed as linear regression equation (p<0.001). The comparison results showed that SH was higher than CS (p<0.05), indicating that the canopy area had an important effect on the difference in stand structure. The average water resources retention rate of the Gotjawal region was 41.9%, which is similar to the total water resources retention rate (40.6%) of Jeju Special Self-Governing Province (JSSGP). Currently, the development of Gotjawal is in progress in JSSGP. The development of Gotjawal will lead to a decrease in the water resources retention rate due to changes in the surface environment such as an increase in impervious areas, which will affect the total groundwater content of JSSGP. Therefore, the conservation of the Gotjawal area is judged to be very important from the point of view of water conservation.

• Journal of Environmental Science International
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• v.28 no.11
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• pp.917-925
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• 2019

All of the animals and the plants in ecosystem are intimately connected to one another and the changes of forests and surroundings affect directly wild animals. This study was conducted at Hangyeong-myeon Cheongsu-ri located in the western part of Jeju Island belonging to Hangyeong Andeok Gotjawal Zone and Jocheon-eup Seonheul-ri located in the eastern part of Jeju Island belonging to Jocheon Hamdeok Gotjawal Zone. The survey on advent of birds was carried out twice a month from January 2014 to December 2015. We divided habitat environments into three survey sites such as a forest, a shrub forest and a farmland. A total of 65 species and 4,802 individuals were observed during the survey period. In a forest, 36 species and 1,287 individuals were observed while A shrub forest had 40 species and 1,554 individuals. And in a farmland, 41 species and 1,961 individuals were observed. The only 10 species were observed in forest and the only 7 species in shrub forest and the only 10 species in farmland. The species diversity and the evenness of a farmland were the highest, and the species richness was the highest in a shrub forest, and the dominance of a forest was the highest among the three areas. The similarity index between a shurb forest and a farmland was high while that between a forest and a farmland was low. The similarity index related with breeding appeared that a forest and a farmland was different from each other.