Abstract. Rewetting drained peatlands can reduce CO₂ emissions but prevents traditional agriculture. Crop production under rewetted conditions may continue with flood-tolerant crops in paludiculture, but its effects on greenhouse gas (GHG) emissions compared to rewetting without further management are largely unknown This study was conducted between 2021 and 2022 on a fen peatland in central Denmark. At the study site, three harvest/fertilization management treatments were implemented on Reed Canary Grass (RCG) established in 2018. Measurements of CO₂ and CH₄ emissions were conducted biweekly using a transparent manual chamber connected to a gas analyzer and manipulating light intensities with four shrouding levels. Although this was a rather wet peatland (−8 cm mean annual WTD), the site was a CO₂ source with a mean net ecosystem C balance (NECB) of 6.5 t C ha⁻¹ yr⁻¹ across treatments. Model simulation with the use of high temporal resolution water table depth (WTD) data was able to better capture ecosystem respiration (R_eco) peaks compared to the use of mean annual WTD, which underestimated R_eco. Data on pore water chemistry further improved statistical linear models of CO₂ fluxes using soil temperature (Ts), WTD, ratio vegetation indices and PAR as explanatory variables. Significant differences in CO₂ emissions and water chemistry parameters were found between studied blocks, with higher R_eco corresponding to blocks with higher pore water nutrient concentrations. Methane emissions averaged 113 kg of CH₄ ha⁻¹ yr⁻¹, equivalent to 11.3 % of the total carbon emission in CO₂ equivalents. Because of large heterogeneity among the experimental blocks no significant treatment effect was found, however, the results indicate that biomass harvest reduces GHG emission from productive rewetted peatland areas in comparison with no management, whereas on less productive areas it is beneficial to leave the biomass unmanaged.

中文翻译：

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高频地下水位数据改进了再湿润泥炭地 paludiculture 的温室气体排放建模


摘要。重新润湿排干的泥炭地可以减少二氧化碳排放，但会阻碍传统农业。在农耕中，耐洪作物在再湿润条件下的作物生产可能会继续进行，但与不进一步管理的再湿润相比，它对温室气体 （GHG） 排放的影响在很大程度上是未知的。这项研究于 2021 年至 2022 年期间在丹麦中部的沼泽泥炭地进行。在研究地点，对 2018 年建立的芦苇金丝雀草 （RCG） 实施了三种收获/施肥管理处理。使用连接到气体分析仪的透明手动室每两周进行一次 CO₂ 和 CH₄ 排放量的测量，并通过四个遮罩级别控制光强度。虽然这是一个相当潮湿的泥炭地（-8 cm 平均年重度），但该地点是一个 CO₂ 来源，不同处理的平均生态系统净 C 平衡 （NECB） 为 6.5 t C ^{ha-1 yr-1}。与使用低估 R_eco 的年平均 WTD 相比，使用高时间分辨率地下水位深度 （WTD） 数据的模型模拟能够更好地捕捉生态系统呼吸 （R_eco） 峰值。使用土壤温度 （Ts）、WTD、比例植被指数和 PAR 作为解释变量，孔隙水化学数据进一步改进了 CO₂ 通量的统计线性模型。在研究的区块之间发现 CO₂ 排放和水化学参数存在显着差异，较高的 R_eco 对应于孔隙水养分浓度较高的区块。甲烷排放量平均为 113 千克 CH₄ ^{ha-1 yr-1}，相当于_CO2 当量碳排放总量的 11.3%。 由于实验块之间的异质性很大，没有发现显着的处理效果，然而，结果表明，与不管理相比，生物质收获减少了生产性再湿润泥炭地地区的温室气体排放，而在生产力较低的地区，不管理生物质是有益的。