| Title |
Biogeochemical Properties of a Forest Stream Dissolved Organic Matter at Mt. Jeombong, a Korean Long-term Ecological Research (KLTER) Site |
| Authors |
이규연(Kyuyeon Lee) ; 차지연(Ji-Yeon Cha) ; 이은주(Eun-Ju Lee) ; 이승철(Seung-Cheol Lee) ; 손승우(Seungwoo Son) ; 김성환(Sunghwan Kim) ; 김현준(Xuanjun Jin) ; 최준원(Joon Weon Choi) ; 오능환(Neung-Hwan Oh) |
| DOI |
https://doi.org/10.15681/KSWE.2025.41.1.54 |
| Keywords |
Biogeochemistry; Carbon; Dissolved organic carbon; Forest stream; Isotopes; KLTER |
| Abstract |
The composition of stream water is the result of various biogeochemical reactions occurring within watersheds. Since 64% of South Korea is covered by forests, studying the components of forest streams is essential to understand the biogeochemical cycling in terrestrial ecosystems. Dissolved organic matter (DOM) is a key subject both in carbon cycle and aquatic ecosystem management. We analyzed stream water practically every month (excluding winter) at the V-notch weir of Mt. Jeombong, the national long-term ecological research site, from 2019 to 2023 when it did not rain. The stream water had no significant seasonal variation, and the concentration of dissolved organic carbon (DOC) was generally low (mean: 1.2 mg L-1). The mean SUVA254, stable carbon isotope ratio, radiocarbon isotope ratio, sum of lignin phenols (Λ8), aromatic carbon ratio using 1H NMR analysis, lignin-like substance ratio, and tannin-like substance ratio of the stream water were 3.6 L mg-1 m-1, -27.0‰, 13.7‰, 1.27 mg/(100 mg of organic carbon), 6.1%, 78.0%, and 13.3%, respectively. The results demonstrate that recently photosynthesized unsaturated organic compounds from dominant C3 plants (angiosperms) in the watershed, can be the main components of stream DOM regardless of the season under near baseflow conditions. However, when snow and ice melted in spring and flowed through the soil layer into the stream, DOC concentration and lignin phenol content increased, indicating the strong role of hydrology on stream DOM dynamics. The results indicate that employing multiple advanced techniques is crucial for understanding changes in DOM quality within Korea’s forest ecosystems. |