Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China.
Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China.
Sci Total Environ. 2023 Sep 10;890:164272. doi: 10.1016/j.scitotenv.2023.164272. Epub 2023 May 19.
Lakes in cold and arid regions have weak hydrological connectivity to their watersheds and serious soil erosion by wind, and are particularly sensitive to changes in underlying surface process and global climate changes, which may result in unique carbon cycles across the terrestrial-aquatic interface and ecological impacts. However, the roles of input pathways of terrestrial dissolved organic matter (TDOM) to lakes in cold and arid regions, especially the effects of possible TDOM input caused by wind erosion, has not been fully understood. Taking a typical lake in cold and arid regions as an example, this study comprehensively investigated the characteristics and contributions of dissolved organic matter (DOM) input from different TDOM input pathways, ultimately highlighted the impacts of wind erosion from composition characteristics, historical changes and universal proofs. The results showed that DOM introduced by wind erosion contributed 37.34 % to all TDOM input, and exhibited the strongest humification and aromaticity, and greatest molecular weight and stability. The considerable input and refractory characteristics led to the differences in the TDOM distribution and DOM composition between the near-wind and far-wind shores of the lake. Moreover, historical analysis showed that wind erosion became the main way driving the changes in buried terrestrial organic matter in the lake through a combined action of precipitation and land cover changes after 2008. The pervasive importance of wind erosion pathways on TDOM inputs in the cold and arid regions was further demonstrated through the proof from two other representative lakes. The findings also shed light on the possible impacts of wind erosion on material distribution, aquatic productivity, and energy input in lake ecosystems. The study provides new insights to broaden the content of global lake-landscape interactions and regional ecosystem conservation.
寒旱区湖泊与流域水文连通性较弱，风蚀作用严重，对下垫面过程和全球气候变化极为敏感，可能导致水陆交错带碳循环独特，并产生生态影响。然而，寒旱区输入陆地溶解有机碳（TDOM）到湖泊的途径的作用，特别是可能由风蚀引起的 TDOM 输入的影响，尚未得到充分理解。本研究以典型寒旱区湖泊为例，综合研究了不同 TDOM 输入途径溶解有机碳（DOM）的输入特征和贡献，最终从组成特征、历史变化和普遍证据方面强调了风蚀的影响。结果表明，风蚀引入的 DOM 对所有 TDOM 输入的贡献为 37.34%，表现出最强的腐殖化和芳香化，以及最大的分子量和稳定性。大量输入和难降解特性导致了湖泊近风和远风岸带 TDOM 分布和 DOM 组成的差异。此外，历史分析表明，风蚀在 2008 年后，通过降水和土地覆盖变化的综合作用，成为驱动湖泊埋藏陆地有机碳变化的主要途径。通过另外两个具有代表性的湖泊的证据，进一步证明了风蚀途径对寒旱区 TDOM 输入的普遍重要性。这些发现还揭示了风蚀对湖泊生态系统物质分布、水生生产力和能量输入的可能影响。本研究为拓宽全球湖陆相互作用和区域生态系统保护的内容提供了新的见解。
