Seasonal dynamics of sediment organic carbon storage for the upper streams of the Yangtze River

作者：Jianfeng Hou, Fei Li, Zhihui Wang, Xuqing Li, Rui Cao, Wanqin Yang · 发表于：Frontiers in Ecology and Evolution · 年份：2023 · DOI：10.3389/fevo.2023.1093448 · 被引用次数：8 · 研究领域：Hydrology and Watershed Management Studies、Hydrology and Sediment Transport Processes、Cryospheric studies and observations

Introduction Forest streams reserve more than 90% of the organic carbon (OC) in sediments, thus playing crucial roles in the global carbon cycle. Although forest streams are widely distributed across various forest regions, seasonal dynamics of OC in forest sediments have not been fully investigated. Methods Here, we sampled soils (0–5 cm) in 15 representative forest stream sediments for 5 critical periods (snowmelt season, early growing season, growing season, late growing season, and seasonal snow cover season) during a one-year investigation in a geologically fragile subalpine coniferous forest catchment in the upper reaches of the Yangtze River in Sichuan province and the OC concentrations were measured by potassium dichromate external heating method. Results The OC concentration of stream sediments ranged from 6.39 to 458.93 g kg −1 , and the average was 84.56 g kg −1 for 15 streams in 5 critical periods during a 1-year investigation. Correspondingly, their stocks ranged from 2.05 to 310.56 kg m −2 , and the average was 46.03 kg m −2 . The maximum and minimum OC stocks were consistently observed during the late growing season and the snowmelt season, respectively. Otherwise, the OC stocks ranged from 1.31 to 218.05, 1.29 to 182.64, and 0.99 to 190.38 kg m −2 for the upstream, midstream, and downstream sediments, and the average was 39.36, 36.58, and 37.93 kg m −2 , respectively. The average ratios of the OC stocks of the upstream and downstream ranged from 0.10–6.31, wit...