Tong Cheuk Hei Marcus, Peichl Matthias, Noumonvi Koffi Dodji, Nilsson Mats B, Laudon Hjalmar, Järveoja Järvi
Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
Glob Chang Biol. 2025 Apr;31(4):e70169. doi: 10.1111/gcb.70169.
Rewetting is considered a strategy for mitigating carbon dioxide (CO) emissions from drained peatlands, with associated climate benefits often derived by applying emission factors (EFs). However, data from rewetted sites are lacking, particularly for boreal peatland forests established on drained nutrient-poor fens. Instead, their EFs have been developed primarily based on data from natural mires, implying similar carbon (C) cycles. In this study, we integrated eddy covariance measurements of ecosystem CO and methane (CH) exchanges with dissolved C export estimates to compare the net ecosystem C balance (NECB) of a recently rewetted minerogenic peatland and two nearby undisturbed fen-type mires in northern Sweden. We found that the rewetted peatland was an annual C source with a mean NECB of +77 ± 34 g C m year (±SD) over the initial 3 years following rewetting. In comparison, the mires were nearly C neutral or a C sink with their 3-year mean NECB ranging between +11 and -34 g C m year. The net CO emission of the rewetted peatland declined to about half by the third year coinciding with an increase in gross primary production. Annual CH emissions from the rewetted peatland steadily increased but remained at 32% and 49% in the first and third year, respectively, relative to the mires. We further noted differences in key environmental response functions of CO and CH fluxes between the rewetted and natural peatlands. Relative to the mires, the dissolved C loss was significantly greater in the rewetted peatland during the first year, but similar in subsequent years. Thus, our study demonstrates that the C balance of a recently rewetted minerogenic peatland may not immediately resemble that of natural mires. This further highlights the need for separate and dynamic EFs to improve estimates of the short-term climate benefit of rewetting measures.
重新湿润被视为一种减少排水泥炭地二氧化碳（CO）排放的策略，通过应用排放因子（EFs）通常能带来相关的气候效益。然而，缺乏来自重新湿润场地的数据，特别是对于在排水的贫营养沼泽地上建立的北方泥炭地森林。相反，它们的排放因子主要是根据天然泥炭沼的数据制定的，这意味着碳（C）循环相似。在本研究中，我们将生态系统CO和甲烷（CH）交换的涡度协方差测量与溶解碳输出估计相结合，以比较瑞典北部一个最近重新湿润的矿质泥炭地和附近两个未受干扰的沼泽型泥炭沼的净生态系统碳平衡（NECB）。我们发现，重新湿润的泥炭地是一个年度碳源，在重新湿润后的最初3年里，平均NECB为+77±34 g C m² 年（±标准差）²。相比之下，泥炭沼接近碳中性或为碳汇，其3年平均NECB在+11至-34 g C m² 年之间。重新湿润的泥炭地的净CO排放在第三年下降到约一半，这与总初级生产力的增加相吻合。重新湿润的泥炭地的年度CH排放量稳步增加，但相对于泥炭沼，在第一年和第三年分别保持在32%和49%。我们还注意到重新湿润的泥炭地和天然泥炭地之间CO和CH通量的关键环境响应函数存在差异。相对于泥炭沼，重新湿润的泥炭地在第一年的溶解碳损失显著更大，但在随后几年中相似。因此，我们的研究表明，最近重新湿润的矿质泥炭地的碳平衡可能不会立即与天然泥炭沼相似。这进一步凸显了需要单独的动态排放因子，以改进对重新湿润措施短期气候效益的估计。 ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ² ²
