Peatlands are effective carbon sinks as more biomass is produced than decomposed under the prevalent anoxic conditions. Draining peatlands coupled with warming releases stored carbon, and subsequent rewetting may or may not restore the original carbon sink. Yet, patterns of plant production and decomposition in rewetted peatlands and how they compare to drained conditions remain largely unexplored. Here, we measured annual above- and belowground biomass production and decomposition in three different drained and rewetted peatland types: alder forest, percolation fen and coastal fen during an exceptionally dry year. We also used standard plant material to compare decomposition between the sites, regardless of the decomposability of the local plant material. Rewetted sites showed higher root and shoot production in the percolation fen and higher root production in the coastal fen, but similar root and leaf production in the alder forest. Decomposition rates were generally similar in drained and rewetted sites, only in the percolation fen and alder forest did aboveground litter decompose faster in the drained sites. The rewetted percolation fen and the two coastal sites had the highest projected potential for organic matter accumulation. Roots accounted for 23–66% of total biomass production, and belowground biomass, rather than aboveground biomass, was particularly important for organic matter accumulation in the coastal fens. This highlights the significance of roots as main peat-forming element in these graminoid-dominated fen peatlands and their crucial role in carbon cycling, and shows that high biomass production supported the peatlands’ function as carbon sink even during a dry year.

泥炭地是有效的碳汇，因为产生的生物量大于在普遍缺氧条件下分解的生物量。排放的泥炭地和变暖会释放储存的碳，随后再润湿可能会也可能不会恢复原始的碳汇。然而，在再湿润的泥炭地中植物生产和分解的方式以及它们与排水条件的比较方式仍未得到充分探索。在这里，我们在异常干旱的一年中，测量了三种不同的排水和再湿润的泥炭地类型的年地上和地下生物量的产生和分解：al木森林，渗流和沿海。我们还使用标准植物材料来比较站点之间的分解，而不考虑本地植物材料的可分解性。重新湿润的部位在渗滤col中具有较高的根和芽产量，而在沿海中则具有较高的根产量，但the木林中的根和叶产量相似。排水和再湿润地区的分解速率通常相似，只有在渗滤区和and木林中，地上垃圾的分解更快。再润湿的渗滤和两个沿海站点的有机物积累潜力最高。根占生物量总产量的23-66％，地下生物量而不是地上生物量对沿海地区有机物积累尤为重要。这凸显了根在这些以类禾草为主的p泥炭地中作为主要泥炭形成元素的重要性，以及它们在碳循环中的关键作用，