Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science and Technology, Nanjing, 210044, China.
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science and Technology, Nanjing, 210044, China.
J Environ Manage. 2023 Oct 15;344:118626. doi: 10.1016/j.jenvman.2023.118626. Epub 2023 Jul 14.
Lakes are recognized as important sources of carbon dioxide (CO) emissions, which vary greatly across land use type. However, CO emissions from lakes in urban landscapes are generally overlooked despite their daily connections to human activity. Furthermore, the role of management actions in CO emissions remained unclear mostly because of the lack of long-term observations. Here, the CO partial pressure (pCO) from two urban lakes (Lake Wuli and Lake Donghu) in eastern China were investigated based on 16-year (2002-2017) field measurements. This long-term measurements showed the annual mean pCO were 1150 ± 612 μatm for Lake Wuli and 1143 ± 887 μatm for Lake Donghu, with corresponding estimated flux of 21.12 ± 19.60 mmol m d and 16.42 ± 20.39 mmol m d, respectively. This indicates significant CO evasion into the atmosphere. Strong links between CO and human-derived nutrients (e.g., ammonium) and dissolved organic carbon, dissolved oxygen, and trophic state index were found. Although pCO was relatively uniform across sites and seasons in each lake, substantial inter-annual variability with significant decreasing trends were found. The decrease in annual CO can be partly explained by the reduction of pollutant loadings with management actions, which held the hypotheses that management actions mitigated the CO emission risks. Overall, management actions (e.g., ecological restoration and municipal engineering) should be considered for better understanding the roles of anthropogenic aquatic ecosystems in carbon cycle.
湖泊被认为是二氧化碳（CO）排放的重要来源，其排放量因土地利用类型的不同而有很大差异。然而，尽管城市景观中的湖泊与人类活动每天都有联系，但它们的 CO 排放通常被忽视。此外，由于缺乏长期观测，管理措施对 CO 排放的作用仍不清楚。在这里，基于 16 年（2002-2017 年）的野外测量，研究了中国东部两个城市湖泊（五里湖和东湖）的 CO 分压（pCO）。这项长期测量表明，五里湖的年平均 pCO 为 1150±612 μatm，东湖的年平均 pCO 为 1143±887 μatm，相应的估计通量分别为 21.12±19.60 mmol m d 和 16.42±20.39 mmol m d，这表明 CO 大量排放到大气中。CO 与人类来源的营养物质（如铵）和溶解有机碳、溶解氧和营养状态指数之间存在强烈的联系。尽管每个湖泊的 CO 在各站点和各季节之间相对均匀，但仍存在大量的年际变化，并呈显著下降趋势。由于管理措施减少了污染物负荷，因此年度 CO 的减少部分可以得到解释，这验证了管理措施减轻了 CO 排放风险的假设。总的来说，应该考虑管理措施（如生态恢复和市政工程），以更好地理解人为水生生态系统在碳循环中的作用。
