Abstract Drained peatlands dominated by purple moor grass (Molinia caerulea) are widespread in the UK and Western Europe. Although substantial carbon stores may be present in these peatlands, in this degraded state they are not currently acting as carbon sinks. Therefore, M.caerulea dominated peatlands have been identified as potential sites for ecohydrological restoration to tackle the current climate emergency. However, at present little is known about whether ditch blocking can raise water tables and promote the recovery of bog plant species, and the subsequent effects on carbon sequestration in these peatlands. To investigate the potential for restoration, we measured changes in water table depth, vegetation composition, photosynthesis at 1000 μmol Photons m−2 s−1 (PG1000), ecosystem respiration (REco) and partitioned below-ground respiration in two M.caerulea dominated peatlands in which drainage ditches had been blocked located in Exmoor National Park, southwest England. Measurements were made in two headwater catchments at ⅛, ¼ and ½ of the distance between adjacent drainage ditches at four control-restored paired sites, during the growing seasons pre- (2012) and post- (2014, 2016 & 2018) restoration. Restoration had a small but significant (p = 0.009) effect on water table depths however, this did not result in a significant change in vegetation composition (p > 0.350). Ecosystem respiration increased in both the control and restored locations following restoration however, this increase was significantly smaller (p = 0.010) at the restored locations, possibly due to a similarly reduced increase in photosynthesis, although this change was not significant (p = 0.116). Below-ground respiration showed no significant changes following restoration. This research illustrates how degraded these shallow peatlands are, and raises concerns that ditch blocking alone may not bring about the high and stable water tables required to perturb the existing Molinia caerulea-dominated ecosystem and substantially alter the carbon balance. Additional restoration measures may be required.

中文翻译：

---

在 Molinia caerulea 主导的浅层泥炭地中，排水管阻塞对温室气体通量的短期影响有限

摘要 以紫色沼泽草（Molinia caerulea）为主的排水泥炭地在英国和西欧很普遍。尽管这些泥炭地中可能存在大量的碳储存，但在这种退化状态下，它们目前并没有充当碳汇。因此，M.caerulea 主导的泥炭地已被确定为生态水文恢复的潜在地点，以应对当前的气候紧急情况。然而，目前关于沟渠堵塞是否可以提高地下水位并促进沼泽植物物种的恢复，以及随后对这些泥炭地的碳固存的影响知之甚少。为了研究恢复潜力，我们测量了 1000 μmol 光子 m−2 s−1 (PG1000) 时地下水位深度、植被组成、光合作用的变化，英格兰西南部埃克斯穆尔国家公园的排水沟被堵塞的两个 M.caerulea 主导的泥炭地中的生态系统呼吸 (REco) 和分区地下呼吸。在恢复前（2012 年）和恢复后（2014 年、2016 年和 2018 年）的生长季节期间，在四个对照恢复配对地点的相邻排水沟之间距离的 ⅛、1/4 和 ½ 处的两个源头集水区进行了测量。恢复对地下水位深度的影响虽小但显着（p = 0.009），但这并未导致植被组成发生显着变化（p > 0.350）。恢复后，对照和恢复位置的生态系统呼吸都增加，然而，恢复位置的这种增加明显更小（p = 0.010），可能是由于光合作用的增加同样减少，尽管这种变化并不显着（p = 0.116）。恢复后地下呼吸没有显着变化。这项研究说明了这些浅层泥炭地的退化程度，并引发了人们的担忧，即仅靠堵塞沟渠可能无法带来扰乱现有的蓝藻占主导地位的生态系统并显着改变碳平衡所需的高而稳定的地下水位。可能需要额外的恢复措施。并引起了人们的担忧，即仅靠沟渠堵塞可能无法带来扰乱现有的蓝藻占主导地位的生态系统和显着改变碳平衡所需的高而稳定的地下水位。可能需要额外的恢复措施。并引起了人们的担忧，即仅靠沟渠堵塞可能无法带来扰乱现有的蓝藻占主导地位的生态系统和显着改变碳平衡所需的高而稳定的地下水位。可能需要额外的恢复措施。