Cui Yuan, Meng Jian-Qiao, Chen Yu-Han, Shao Fei-Fan, Chen Xuan-Zheng, Jin Yu, Zhang Ming-Xiang, Yun-Qian Guo, Luo Fang-Li, Yu Fei-Hai
School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China.
College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
Environ Res. 2023 Apr 15;223:115482. doi: 10.1016/j.envres.2023.115482. Epub 2023 Feb 10.
The modification of dissolved organic matter (DOM) degradation by plant carbon inputs represents a critical biogeochemical process that controls carbon dynamics. However, the priming effects (PEs) different plant tissues induce on the degradation of DOM pools with different stabilities remain unknown. In this study, PEs, induced by different tissue leachates of Phragmites australis, were evaluated via changes in DOM components and properties of both fresh and tidal water (with different stabilities). The results showed that DOM derived from different plant tissue leachates differed in composition and bioavailability. Inputs of tissue leachates induced PEs with different intensities and directions (negative or positive) on DOM degradation of fresh and tidal water. In fresh water, the PEs of leaf and root leachates were significantly higher than those of stem and rhizome leachates. The PE direction changed for DOM degradation between fresh and tidal water. The addition of leaf and root leachates tended to induce positive PEs on DOM degradation of fresh water, while resulting in negative PEs on DOM degradation of tidal water. Negative PEs for tidal water DOM may be due to preferential utilization of microbes, high salinity, and/or the promotion of exogenous DOM production from plant tissues. The results indicate that intensity and direction of PEs induced by plant leachates depend on both leachate type and water stability. The findings highlight the necessity to examine the nature of exogenous and native DOM when interpreting the interactive processes that regulate DOM degradation.
植物碳输入对溶解有机物（DOM）降解的影响是控制碳动态的关键生物地球化学过程。然而，不同植物组织对不同稳定性DOM库降解所诱导的激发效应（PEs）仍不清楚。在本研究中，通过新鲜水和潮水（具有不同稳定性）中DOM成分和性质的变化，评估了芦苇不同组织浸出液诱导的PEs。结果表明，来自不同植物组织浸出液的DOM在组成和生物可利用性方面存在差异。组织浸出液的输入对新鲜水和潮水中DOM的降解诱导了不同强度和方向（负或正）的PEs。在淡水中，叶和根浸出液的PEs显著高于茎和根状茎浸出液。新鲜水和潮水中DOM降解的PE方向发生了变化。添加叶和根浸出液倾向于对淡水DOM降解诱导正的PEs，而对潮水DOM降解产生负的PEs。潮水DOM的负PEs可能是由于微生物的优先利用、高盐度和/或植物组织中外源DOM产生的促进作用。结果表明，植物浸出液诱导的PEs的强度和方向取决于浸出液类型和水的稳定性。这些发现强调了在解释调节DOM降解的相互作用过程时，研究外源和天然DOM性质 的必要性。
