The role played by reservoirs in the biogeochemical cycles of elements is a subject of ongoing debate. Recent research has revealed that reservoirs emit significant levels of greenhouse gases. To assess the importance of reservoirs in monsoon climate areas as a source of methane gas into the atmosphere, we investigated variations in organic carbon (OC) input into the reservoir, oxic state changes, and finally the amount of methane emitted (focusing on the ebullition pathway) in Lake Soyang, which is the largest reservoir in South Korea. Total organic carbon (TOC) concentrations were higher during summer after two years of heavy rainfall. The sedimentation rates of particulate organic carbon (POC) and particulate organic nitrogen (PON) were higher in the epilimnion and hypolimnion than the metalimnioin, indicating that autochthonous and allochthonous carbon made separate contributions to the TOC. During stratification, oxygen depletion occurred in the hypolimnion due to the decomposition of organic matter. Under these conditions, H2S and CH4 can be released from sediment. The methane emissions from the reservoir were much higher than from other natural lakes. However, the temporal and spatial variations of methane ebullition were huge, and were clearly dependent on many factors. Therefore, more research via a well-organized field campaign is needed to investigate methane emissions.

한국산 호박과 일본산 호박을 주서로 갈아서 30분간 끓인 다음 착즙, 원심분리하여 당을 분석하였다. 한국산 호박의 수크로오스 함량은 0.41%, 프룩토오스는 0.54%, 글루코오스는 0.61%, 전분은 0.68%를 나타냈다. 일본산 호박은 수크로오스 2.60%, 프룩토오스 2.76%, 글루코오스 1.91% 전분 1.22%를 나타냈다. 다른 소당은 검출되지 않았다. 일본산 호박 전분을 NMR로 분석한 결과 α-1, 4-글루코시드 결합만 나타냈으며, 요오드반응의 흡광도는 아밀로오스(DP 117)의 86%를 나타내 아밀로오스만으로 구성된 것으로 나타났다. 카르바졸법으로 펙틴 함량을 분석한 결과 한국산 호박은 6.29%, 일본산 호박은 2.67%를 나타냈다.