The priming effect (PE) is recognized as an important mechanism influencing organic matter transformation in aquatic systems. The land-ocean aquatic continuum (LOAC) has received large quantities of dissolved organic matter (DOM) from various sources, which is an ideal interface for PE research. Here, we investigated the PE process by utilizing such a coastal environment to explore the turnover of DOM in the LOAC system. Suwannee River natural organic matter was selected as the background, and various external environmental samples were introduced to track the changes of organic carbon. The PE process together with the variations of DOM sources, compositions, and structures was characterized. Generally, river and estuary environments exhibited a positive PE, while the offshore zone showed a negative effect. Additionally, nutrients, salinity, and DOM composition all contributed to the PE. After the incubation, the feature of carbon sources transferred from terrestrial to autochthonous. The carbonyl and alcohol functional groups significantly decomposed, while the methyl and methylene groups increased and heteroatoms further accelerated the PE process. The data also shows that special parameters and molecular markers can be utilized to track the carbon response to the PE. This research indicates that the change of carbon flux and the imbalance of its budget in aquatic systems could be partially explained from the perspective of the PE.

中文翻译：

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追踪引发效应触发的 DOM 组成、转化和循环机制的变化：来自孵化实验的见解


引发效应 （PE） 被认为是影响水生系统中有机物转化的重要机制。陆地-海洋水生连续体 （LOAC） 从各种来源接收了大量溶解有机物 （DOM），这是 PE 研究的理想界面。在这里，我们利用这样的沿海环境研究了 PE 过程，以探索 DOM 在 LOAC 系统中的周转率。以 Suwannee 河天然有机质为背景，引入各种外部环境样本，跟踪有机碳的变化。表征了 PE 过程以及 DOM 来源、成分和结构的变化。一般来说，河流和河口环境表现出积极的 PE，而近海地区表现出消极的影响。此外，营养物质、盐度和 DOM 组成都对 PE 有贡献。孵化后，碳源的特征从陆地转移到本土。羰基和醇官能团显著分解，甲基和亚甲基增加，杂原子进一步加速了 PE 过程。数据还表明，可以使用特殊参数和分子标记来跟踪碳对 PE 的响应。这项研究表明，水生系统中碳通量的变化及其预算的不平衡可以从 PE 的角度部分解释。