泥炭地高效碳累积功能的化学生态学机理

Peatland is the most effective wetland ecosystem of carbon accumulation, which plays an important role in global carbon cycle. However, chemical ecological mechanism of highly effective carbon accumulation in a peatland is always unclear at the molecular level. We will carry out this study in a typical ombrogenous peatland located in the Changbai Mountains, Northeast China. Recalcitrant Sphagnum mosses and labile vascular plants will be collected as main experiment materials. Our study will be divided into four parts: 1. To start with molecular chemistry of organic matter, we will try to establish molecular chemical archives for organic carbon stock of the ombrogenous peatland in Northeast China, set up a quantitative model of the relationship between molecular chemical composition, degree of decomposition and stratigraphic age, and further elucidate the vertical distribution profile of molecular chemical composition at different depths as well as molecular chemical composition and structural characteristics of the recalcitrant peat organic components; 2. The simulation experiments in vitro and their ananlyses will indicate the biochemical mechanism of anti-decomposability of macromolecules such as polysaccarides and polyphenols in the peat-forming plant Sphagnum and interaction between soluble monosaccarides and free phenols; 3. The decomposition experiments in the study site and their litter analyses will illuminate the interplay between the recalcitrant peat organic components and water table; 4. Overall, chemical ecological mechanism of highly effective carbon accumulation in a peatland will be deeply revealed at the molecular level.

泥炭地是碳累积最为高效的湿地生态系统，在全球碳循环中发挥着重要作用，然而泥炭地高效碳累积功能在分子水平上的化学生态学机理一直不清楚。本项目以东北长白山山地的雨养型泥炭地为研究区，以耐分解的泥炭藓和易分解的维管束植物为主要实验物种，进行以下四个方面的研究：一、从有机质的分子化学研究着手，尝试利用裂解/气相色谱-质谱仪为东北雨养型泥炭地有机碳库建立分子化学档案，构建泥炭有机质的分子化学组成、分解程度和地层年代三者之间关系的定量模型，阐明雨养泥炭地有机质分子化学组成的地层垂直分异规律，明晰泥炭耐分解有机组分的分子化学组成与结构特征；二、通过室内模拟实验测试，阐明成炭植物泥炭藓结构有机大分子多糖和多酚及其小分子水解产物抗分解的生物化学作用机制；三、通过野外分解实验和植物残体分析，阐明耐分解有机组分和水位条件的交互作用关系；四、综合以上研究，在分子水平上深刻揭示泥炭地高效碳累积功能的化学生态学机理。

泥炭地高效碳累积功能在分子水平上的化学生态学机理一直不清楚，本项目以东北长白山山地的雨养型泥炭地为研究区，利用裂解/气相色谱-质谱为主要技术手段，有如下四个发现：一、泥炭藓经过分解发生了复杂的生化反应，而泥炭更加稳定且组分复杂；二、在泥炭藓分解过程中，苯酚类物质会慢慢形成并积累；三、泥炭藓头状花枝部分糖类物质含量较高，而泥炭表层不含糖类物质，说明糖类物质不稳定容易分解；四、在分子水平上，检测到多酚对泥炭地高效碳累积功能起主导作用。