Helmholtz Centre for Environmental Research - UFZ, Brückstrasse 3a, 39114 Magdeburg, Germany.
Martin Luther University Halle-Wittenberg, Institute of Agricultural and Nutritional Sciences, Julius-Kühn Str. 23, 06112 Halle, Germany.
Sci Total Environ. 2017 May 15;586:770-781. doi: 10.1016/j.scitotenv.2017.02.054. Epub 2017 Feb 16.
Peatlands can be a potential source of dissolved organic matter (DOM) in fresh water catchment areas. The quantity and quality of DOM can differ between pristine, degraded and rewetted peatlands. Due to the large scale and continuing losses of peatlands, their conservation and restoration has been increasingly emphasized. Mostly rewetting measures are required to improve the hydrology of damaged peatlands, which is a precondition for the resettlement of peat-forming plant species. Thus, in term of DOM, there is a special need to understand how rewetting measures affect DOM characteristics and concentrations. To estimate the potential leaching of humic substances from rewetted areas two natural sites were compared with four artificially rewetted sites in a peatland area of the Harz Mountains National Park, Germany. This was done with regards to DOM quality by combining the results from Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS, measured at one time in Spring) and excitation-emission-matrix fluorescence spectroscopy (EEMF, measured monthly for the period of one year). The DOM quality was significantly less variable in the pristine peatland soil water compared to the rewetted peatland soil waters, from both a spatial and a seasonal perspective. The soil water from the rewetted peatland sites showed a higher degree of humification compared to pristine peatland. DOC concentration was mostly consistent in the pristine peatland over the year. The rewetted peatlands showed higher DOC levels in Summer months and lower DOC in Winter months compared to the pristine peatland. It can be concluded that the rewetting of peatlands is coupled with high concentrations of DOC in soil water and its quality is highly aromatic (as reflected by the observed values from the humification index) during times with elevated temperature. The results may have a significant input for dynamic catchment area studies with regards to rewetting peatland sites.
泥炭地可能是淡水集水区中溶解有机物质 (DOM) 的潜在来源。原始、退化和重新湿地化的泥炭地之间 DOM 的数量和质量可能存在差异。由于泥炭地大规模持续流失，泥炭地的保护和恢复越来越受到重视。主要需要采取重新湿地化措施来改善受损泥炭地的水文状况，这是重新定居泥炭形成植物物种的前提条件。因此，就 DOM 而言，特别需要了解重新湿地化措施如何影响 DOM 特性和浓度。为了估算从重新湿地地区淋滤出腐殖质的潜力，在德国哈茨山脉国家公园的泥炭地地区，将两个自然地点与四个人工重新湿地地点进行了比较。这是通过将傅里叶变换离子回旋共振质谱（FT-ICR-MS，在春季一次性测量）和激发-发射矩阵荧光光谱（EEMF，在一年的时间内每月测量）的结果相结合，从 DOM 质量方面进行的。与重新湿地化的泥炭地土壤水相比，原始泥炭地土壤水中的 DOM 质量在空间和季节上的变化都要小得多。与原始泥炭地相比，重新湿地化泥炭地土壤水中的腐殖化程度更高。DOC 浓度在整个一年中在原始泥炭地中基本保持一致。与原始泥炭地相比，重新湿地化的泥炭地在夏季月份的 DOC 水平较高，而在冬季月份的 DOC 水平较低。可以得出结论，泥炭地的重新湿地化伴随着土壤水中高浓度的 DOC，并且在高温时期其质量具有高度的芳香性（如腐殖化指数所反映的观测值）。这些结果对于重新湿地化泥炭地地点的动态集水区研究可能具有重要的输入。
