Aims This study assesses the relative effects of hydrology and colonization by vascular plants on belowground C and N mobilization, and emission of CO 2 and CH 4 in an extracted bog under restoration in Alberta (Canada). Methods A wet (high water table) and dry (low water table) area were identified at the site and plots with cottongrass ( Eriophorum vaginatum ) or bare peat were established in each area. Plant growth, peat and porewater dissolved C (DOC) and N (TDN), microbial biomass and the emissions of CO 2 and CH 4 were monitored at the plots throughout the growing season. Results The largest concentrations of DOC were measured in dry and bare sites. Lower E2:E3 ratios suggested a higher aromaticity of the DOC at these sites that were net sources of CO 2 and CH 4 . The concentration of TDN was greater in plots with cottongrass and high water table, supporting a more abundant microbial biomass. Cottongrass dominated plots also had larger gas emissions as compared to bare plots even though they were net C sinks due to their high photosynthetic rates. Conclusion Maintaining a high water table is key to reducing peatland C losses. While vascular plant presence seems to prime the release of N and greenhouse gases, the inputs of C exceeded the losses and recovered the C sink function of the peatland ecosystem in the short term. Carbon inputs are maximized under high water table and plant presence.

中文翻译：

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植被和地下水位深度对恢复泥炭地地下碳氮迁移和温室气体排放的交互作用

目的 本研究评估了水文和维管植物定植对地下 C 和 N 流动以及 CO 2 和 CH 4 在艾伯塔（加拿大）恢复中的提取沼泽排放的相对影响。方法在现场确定湿（高水位）和干（低水位）区域，并在每个区域建立棉草（Eriophorum vaginatum）或裸泥炭地块。植物生长、泥炭和孔隙水溶解的 C (DOC) 和 N (TDN)、微生物生物量以及 CO 2 和 CH 4 的排放在整个生长季节在地块上进行监测。结果 在干燥和裸露的地点测得的 DOC 浓度最高。较低的 E2:E3 比率表明这些地点的 DOC 具有较高的芳香性，这些地点是 CO 2 和 CH 4 的净来源。TDN 浓度在棉草和高地下水位的地块中更高，支持更丰富的微生物生物量。与裸地相比，以棉草为主的地块的气体排放量也更大，尽管它们由于光合速率高而成为净碳汇。结论 保持高地下水位是减少泥炭地 C 损失的关键。虽然维管植物的存在似乎是 N 和温室气体释放的主要因素，但 C 的输入超过了损失，并在短期内恢复了泥炭地生态系统的 C 汇功能。在高地下水位和植物存在的情况下，碳输入最大化。结论 保持高地下水位是减少泥炭地 C 损失的关键。虽然维管植物的存在似乎是 N 和温室气体释放的主要因素，但 C 的输入超过了损失，并在短期内恢复了泥炭地生态系统的 C 汇功能。在高地下水位和植物存在的情况下，碳输入最大化。结论 保持高地下水位是减少泥炭地 C 损失的关键。虽然维管植物的存在似乎是 N 和温室气体释放的主要因素，但 C 的输入超过了损失，并在短期内恢复了泥炭地生态系统的 C 汇功能。在高地下水位和植物存在的情况下，碳输入最大化。