On April 29, 2021 (1st), June 2 (2nd), and August 17 (3rd), we surveyed benthic macroinvertebrates fauna at Muljangori-oreum wetland in Bonggae-dong, Jeju Island, Korea. Muljangori-oreum wetland was divided into four areas. The survey was conducted in three accessible areas (areas 1-3). As a result of habitat environment analysis, the average monthly temperature from 2017 to 2021 was the highest in July and August and the lowest in December and February. This pattern was repeated. As a result of analyzing changes in vegetation and water surface area through satellite images, normalized difference vegetation index (NDVI) increased from February to July and decreased after July. Normalized difference water index (NDWI) was analyzed to show an inverse relationship. A total of 21 species from 13 families were identified in the qualitative survey and a total of 412 individuals of 24 species from 15 families were identified in the quantitative survey. A total of 26 species from 17 families, 8 orders, 3 classes, and 2 phyla of benthic macroinvertebrates were identified. The dominant species was Chronomidae spp. with 132 individuals (32.04%). Noterus japonicus was a subdominant species with 71 individuals (17.23%). As a result of comparative analysis of species identified in this study and the literature, it was confirmed that species diversity was high for Coleoptera and Odonata. Main functional feeding groups (FFGs) were found to be predators. Habitat orientation groups (HOGs) were found to be swimmers. In OHC (Odonata, Hemiptera, and Coleoptera) group, 17 species (73.91%) in 2021, 23 species (79.31%) in 2016, 26 species (86.67%) in 2018, and 19 species (79.17%) in 2019 were identified. Cybister japonicus, an endangered species II, was confirmed to inhabit Muljangori-oreum wetland in the literature. Ten individuals (2.43%) were also confirmed to inhabit Muljangori-oreum wetland in 2021. Therefore, continuous management and habitat protection are required to maintain the habitat environment of C. japonicus in Muljangori-oreum wetland.

클라우제비츠는 『전쟁론』에서 전쟁은 개별 상황마다 그 본질을 약간씩 변화시키기 때문에 카멜레온과도 같다고 보았다. 클라우제비츠의 이러한 주장은 모든 것이 불확실한 전쟁 상황에서 다양한 요소들이 상호작용을 하여 승패에 영향을 미칠 수 있음을 언급한 것이다. 이 글에서는 불확실성 의 요인이 되는 우연과 마찰, 정보, 위험, 육체적 고통을 토대로 이를 해 소하기 위한 5가지 방안을 도출하여 제1연평해전과 연평도 포격전 사례를 분석하였다. 분석 결과 첫째, 실전적 교육훈련, 둘째, 과감한 권한 위임, 셋째, 부대 운용의 융통성, 넷째, 간단없는 작전지속 지원, 다섯째, 피아 전술 전기 숙달 등을 통해 불확실성을 해소하고 전승을 달성할 수 있었음 을 확인할 수 있었다. 이것이 한국군에 주는 함의로는 첫째, 창의적인 사 고력과 탄력적인 부대지휘 능력을 배양하기 위한 교육훈련의 필요성, 둘 째, 전술교리 적용에 융통성 없이 집착하는 문화 지양, 셋째, 군인으로서 ‘인생의 첫 전투’를 어떻게 수행할 것인가에 대한 준비가 필요하다. 비록 군사과학 기술이 발전하여 전장 상황을 가시화할 수 있게 되더라도 전쟁 의 근본적인 본질인 불확실성은 전쟁 수행에 커다란 영향을 미치는 변수 라는 것을 망각해서는 안 될 것이다.

우리나라 난온대 도서지역을 광범위하게 조사해 TWINSPAN분석을 통해 식생을 유형화한 후에 유형별 입지환경과 군집구조 특성을 밝혔다. 이를 바탕으로 식생유형별 복원전략을 도출하여 난온대림 복원계획의 방향성을 제시하고자 했다. 식생유형은 명료하게 8개로 나뉘었는데 군락Ⅰ∼Ⅳ는 후박나무, 구실잣밤나무 등이 우점한 양호한 상록활엽수림 이었다. 반면, 군락Ⅴ∼Ⅷ은 곰솔림과 낙엽활엽수림, 인공조림지로 난온대 지역의 퇴행천이 식생이었다. DCA분석 결과로 도출된 환경요인은 해발고(최한월 평균기온)와 해안선에서 거리(내염성)였다. 2가지 환경요인에 따라 후박나무 림, 구실잣밤나무림, 가시나무류림 유형으로 난온대림 분포패턴이 명료해졌다. 3가지 식생유형을 복원대상지의 입지환 경을 고려해 복원목표 식생으로 적용하는 것이 합리적이다. 군락Ⅴ∼Ⅷ에는 곰솔, 낙엽활엽수 등이 수관층을 형성했는 데 종자 확장력이 강한 상록활엽수종이 하층에 빈번하게 출현해, 상록활엽수림으로 식생천이 가능성이 컸다. 도서지역 에 산림이 사라진 황폐지는 협소하지만, 곰솔림과 낙엽활엽수림 등의 퇴행천이된 식생이 대면적을 이룬다. 이곳을 상록활엽수림으로 갱신하는 복원전략이 탄소중립 실현과 생물다양성 증진 측면에서 효과성이 더 클 수 있다.

n this research, the dose rate was measured using backpack-type scan survey device at 4 sites on Jeju Island, and the radioactivity ratio for each nuclide was evaluated using an high-purity germanium (HPGe) detector. As a result of measuring the dose rate with a backpack-type scan survey device, the average dose rate was the lowest in the measurement site 3 at 0.049 Sv/h, and the highest in the measurement site 1 at 0.066 Sv/h. The average dose rate of the 4 sites on Jeju Island was 0.056 Sv/h, and the dose rate on Jeju Island was lower than that of other regions. The data acquired by scan survey were interpreted using classed post and gridding function of surfer program. The radioactivity ratio of each nuclide in the gamma spectrum measured by the HPGe detector was the highest for K-40 with an average of 87.62%, and the lowest for Pb-214 with an average of 0.63%. In the case of the Jeju Island site, Cs-137 was detected, and the average radioactivity ratio of Cs-137 was 3.27%, which was the background level. The results of this research can be used as basic data on the radioactivity ratio for each nuclide and dose rate at the Jeju Island site. Further studies on the assessment of dose rates and radioactivity ratios in other regions are needed.

This study presents distribution of naturally occurring radioactive materials in groundwater in Jeju island. Radon (222Rn) and potassium (40K) concentrations were performed by using RAD H2O of RAD7 and 940 Professional IC Vario, respectively. In addition, the activities of uranium and thorium nuclides were analyzed by ICP-MS. All of the groundwater samples were collected from 29 sites from August to October 2022. The radon concentrations in groundwater were in the range of 0 to 60 Bq L-1, and there was no groundwater exceeding the range of 148 Bq L-1 proposed by the US EPA. The distribution of uranium in groundwater varied from 0 to 0.6 μg L-1 and did not exceed 30 μg L-1, thresholds indicated by the US EPA.

In the coastal areas of Jeju Island, composed of volcanic rocks, saltwater intrusion occurs due to excessive pumping and geological characteristics. Groundwater level and electrical conductivity (EC) in multi-depth monitoring wells in coastal areas were characterized from 2005 to 2019. During the period of the lowest monthly precipitation, from November 2017 until February 2018, groundwater level decreased by 0.32-0.91 m. During the period of the highest monthly precipitation, from September 2019 until October 2019, groundwater level increased by 0.46-2.95 m. Groundwater level fluctuation between the dry and wet seasons ranged from 0.79 to 3.73 m (average 1.82 m) in the eastern area, from 0.47 to 6.57 m (average 2.55 m) in the western area, from 0.77 to 8.59 m (average 3.53 m) in the southern area, and from 1.06 to 12.36 m (average 5.92 m) in the northern area. In 2013, when the area experienced decreased annual precipitation, at some monitoring wells in the western area, the groundwater level decreased due to excessive groundwater pumping and saltwater intrusion. Based on EC values of 10,000 μS/cm or more, saltwater intrusion from the coastline was 10.2 km in the eastern area, 4.1 km in the western area, 5.8 km in the southern area, and 5.7 km in the northern area. Autocorrelation analysis of groundwater level revealed that the arithmetic mean of delay time was 0.43 months in the eastern area, 0.87 months in the northern area, 10.93 months in the southern area, and 17.02 months in the western area. Although a few monitoring wells were strongly influenced by nearby pumping wells, the cross-correlation function of the groundwater level was the highest with precipitation in most wells. The seasonal autoregressive integrated moving average model indicated that the groundwater level will decrease in most wells in the western area and decrease or increase in different wells in the eastern area.

To isolate aerobically and identify the diversity of halophilic bacteria in the soil around two ports, Daepopogu and Hwasun Port, on Jeju island, a total 46 halophilic bacteria strains were isolated and phylogenetically analysed. The isolated strains were divided into 3 phyla, 8 families, 16 genera and 23 species. The main taxa was the Bacilli class, which included 50.0% of the strains with 3 families, 10 genera and 15 species of Bacillaceae, Exiguobacterium_f and Planococcaceae. The second taxa was the Gammaproteobacteria class, which included 45.7% of the strains with 4 families, 5 genera and 7 species of Aeromonadaceae, Halomonadaceae, Marinobacteraceae and Vibrionaceae. The isolated strains were tested for hydrolytic enzymes, amylase, lipase and protease activity, and 31 strains showed activity of at least one enzyme. Furthermore, auxin activity was determined in 7 strains. This study showed that the isolated strains have possible applications in the food and agricultural industries and have importance as a genetic resource in Korea.

The proposal in this paper outlines an idea for a Korean Peninsula focused Peace Cruise starting from Jeju World Peace Island and going up the eastern coast of the peninsula ， taking in a port or two in Japan (such as Fukuoka) to accommodate potential Korean-descended passengers there and ending at Wonsan, where a grove of Jeju King Cherry (Prunus Yedoensis var. Nudiflora) trees could be planted progressively as a welcome avenue for those on the peace cruise ship. This grove of Jeju King Cherry trees will grow each time a Jeju World Peace Island Peninsula Cruise arrives. Wonsan has been a holiday place for the DPRK for some time and with the permission of that country could become a limited and controlled international destination for Peace and, perhaps, other cruise tours. There are precedents internationally for special zones to be declared for specific activities. Such places frequently become economic development zones for the host country. After successful itineraries have been shown, the Jeju World Peace Island ship could extend its cruise north to ports on the Kamchatka Peninsula and west to Chinese ports interested in the concept

We investigated the effect of habitat environment and colony characteristics on floral bud development in Rhododendron brachycarpum native to Ulleung Island of Korea. Two habitats were considered. Habitat B had a remarkably higher altitude and steeper slope than habitat A. Therefore, fewer types of trees existed on the upper layers, and the density was low. Hence, the degree of light transmission within the community was higher in habitat B. Additionally, flowering ratio of shoots was higher in habitat B, and the amount of light was also relatively higher. The lower the amount of light, lesser the floral development, the higher the leaf area and the specific leaf area, lower the dry weight and chlorophyll content. The total carbohydrate (T-C) and nitrogen (T-N) in shoots are more important than the relative T-C and T-N ratios per leaf. Finally, this study revealed that the floral bud development and flowering of native rhododendrons are strongly associated with the degree of assimilate accumulation in shoots, and that sufficient assimilate accumulation in shoots is essential for stable flowering.

PURPOSES : The objective of this study is to develop regression models for surface distress (SD), rut depth (RD), and international roughness index (IRI) of Jeju Island local road by analyzing the correlations between the pavement performance and its influencing factors. METHODS : First, the differences between pavements in inland Korea and Jeju Island in terms of performance and influencing factors were investigated. Influencing factors were assigned to pavement sections on Jeju Island using the inverse distance weighting method, and the correlations between the pavement performance and influencing factors were analyzed. As a result, maximum temperature, heat wave days, annual temperature range, precipitation days, precipitation intensity, ESAL, etc. were determined as independent variables for the pavement performance prediction models. Multiple regression analysis was performed to develop the pavement performance models using the selected independent variables. RESULTS : The RD, maximum temperature, and precipitation days were determined to be the independent variables for the SD predictive model. The SD, maximum temperature, annual temperature range, heat wave days, and precipitation days were selected as independent variables of the RD prediction model. In addition, the RD, annual temperature range, heat wave days, precipitation days, and ESAL were selected as independent variables for the IRI prediction model. CONCLUSIONS : As a result of the study, an actual forecast model for SD, RD, and IRI was developed. Based on this model, it is possible to estimate the predictive value of the missing performance data in the studied interval. If the factors affecting performance are managed in terms of maintenance beyond a certain level, it can help those responsible for road maintenance to rationally select the maintenance method and timing.