研究报告
叶琳琳,吴晓东,刘波,闫德智.长江感潮河段有机碳的潮汐和季节变化规律[J].环境科学学报,2022,42(7):338-346
长江感潮河段有机碳的潮汐和季节变化规律
- Tidal and seasonal variation in the concentrations of the organic carbons in the tidal freshwater reach of Changjiang River
- 基金项目：国家自然科学基金项目（No. 41871060）
- 作者
- 单位
- 叶琳琳
- 南通大学地理科学学院，南通 226000
- 吴晓东
- 中国科学院西北生态环境资源研究院冰冻圈科学国家重点实验室，兰州 730000
- 刘波
- 南通大学地理科学学院，南通 226000
- 闫德智
- 南通大学地理科学学院，南通 226000
- 摘要：以长江感潮河段─南通段为研究对象，于2019年逐月采集涨潮和落潮期间分层水体样品. 测定了颗粒有机碳（particulate organic carbon， POC）和溶解有机碳（dissolved organic carbon， DOC）浓度，并同步进行了不同营养盐添加的室内模拟实验，测定了生物可降解溶解有机碳（biodegradable DOC， BDOC）的浓度. 研究结果表明，底层POC浓度最高，中层POC浓度最低. POC浓度与潮高呈显著负相关，与水温没有显著相关性. 表层、中层和底层DOC浓度没有显著差异，DOC浓度均值为（7.55 ± 1.50） mg·L-1. 涨潮和落潮DOC浓度没有显著差异，DOC浓度与水温呈显著正相关. BDOC在DOC中的占比为40.88% ± 13.91%，不同营养盐添加处理的BDOC在DOC中的占比没有显著差异. BDOC浓度和潮高呈显著正相关. 这些研究结果表明，与POC 不同， DOC和BDOC具有显著季节变化规律. 长江下游潮汐作用对有机碳的分布具有重要影响，涨潮对POC产生稀释作用，但促进了DOC生物可降解性的升高.
- Abstract：Water samples at three depths at the flood and ebb peaks were collected monthly in the lower tidal reach of Changjiang River （Nantong section）. Particulate organic carbon （POC） and dissolved organic carbon （DOC） were analyzed， as well as biodegradable dissolved organic carbon （BDOC） with different nutrient amendments. These results showed a significant difference in POC concentrations among the different layers， with the highest concentration at the bottom and the lowest in the middle. POC concentrations were significantly negatively correlated with tide height and had no significant relationship with water temperature. No significant difference in DOC concentration was observed among the surface layer， middle layer and bottom. The averaged concentration of DOC in Nantong section was 7.55 ± 1.50 mg·L-1. The concentration of DOC showed no significant difference between the food peak and ebb peak. DOC concentration
s were positively correlated with water temperature. BDOC constitutes 40.88% ± 13.91% of DOC. No significant difference in BDOC concentration was observed among different nutrient amendments. A significant positive correlation was observed between BDOC concentration and tide height. These results suggested that different from POC， DOC and BDOC exhibit seasonal changes. The tide is an important factor in regulating both POC and DOC dynamics in the rivers section are affected by tide events， tide decreases POC concentration but increases biodegradable DOC in the freshwater tidal reach of Changjiang River.
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