An undesired succession of rich fens leads to the formation of dense Sphagnum carpets that outcompete brown mosses and some vascular plants, resulting in biodiversity loss in fen habitats of high conservation importance. Small-scale Sphagnum removal is a rarely implemented conservational measure, whose success may depend on soil alkalinity and fertility (i.e., nutrient availability). Therefore, characterizing the effects of pH and fertility levels would potentially allow for the development of better Sphagnum removal strategies. Two experiments were conducted across 24 rich fens of different alkalinity and fertility located in an area of ~32,000 km² spanning from the Bohemian Massif to the Western Carpathians (Europe). We hypothesized that high alkalinity and low fertility support the restoration of rich fen vegetation after Sphagnum removal. Our study focused on four different Sphagnum groups. In Experiment 1, the treatment plots remained unfenced. In Experiment 2, the treatment plots were fenced off and target brown mosses were transplanted from the surroundings to overcome dispersal limitations. A repeated-measures design was used, with vegetation composition recorded over a 5-year period. High alkalinity rather than fertility facilitated species richness and the appearance of target brown mosses. High alkalinity generally hindered Sphagnum recovery, whereas high fertility supported the recurrence of S. teres and S. recurvum agg. Under high pH conditions, enhanced fertility further correlated with the spread of nonsphagnaceous generalist bryophytes of low conservation value. Despite sustaining a significant overall reduction, all Sphagnum taxa began to recover throughout the experiment, albeit less obviously in fens with S. warnstorfii. Sphagnum removal may reverse biodiversity loss and allow for the restoration of brown mosses in rich fens where Sphagnum cover had increased due to slight eutrophication, acidification, or a decrease in the water table. In alkaline and nutrient-poor conditions (e.g., S. warnstorfii fens), the effect is evident and long lasting and the intervention may not be extensive. In fens dominated by S. teres or S. recurvum agg., repeated or large-scale removal may be needed if high nutrient availability (potassium, phosphorus) or low alkalinity supports Sphagnum recolonization. Treatment plots with S. subgenus Sphagnum exhibited the least promising brown-moss restoration prospects.

中文翻译：

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去除泥炭藓能否扭转不同碱度和肥力水平下富沼泽的不受欢迎的演替？

丰富的沼泽地的意外连续导致形成致密的泥炭藓地毯，在竞争中胜过棕色苔藓和一些维管植物，导致具有高度保护重要性的沼泽生境的生物多样性丧失。小规模去除泥炭藓是一种很少实施的保护措施，其成功可能取决于土壤碱度和肥力（即养分可用性）。因此，表征 pH 和肥力水平的影响可能会允许开发更好的泥炭藓去除策略。在 32,000 km ^{2范围内的 24 个不同碱度和肥力的肥沃沼泽地进行了两次实验}从波希米亚地块到西喀尔巴阡山脉（欧洲）。我们假设高碱度和低肥力支持去除泥炭藓后丰富的沼泽植被的恢复。我们的研究侧重于四个不同的泥炭藓类群。在实验 1 中，处理地块仍然没有围栏。在实验 2 中，将处理地块围起来，并从周围移植目标棕色苔藓以克服扩散限制。使用了重复测量设计，记录了 5 年期间的植被组成。高碱度而不是肥力促进了物种丰富和目标棕色苔藓的出现。高碱度普遍阻碍泥炭藓恢复，而高生育率支持S. teres和S. recurvum agg 的复发。在高 pH 值条件下，生育力的提高进一步与保护价值低的非泥炭科综合性苔藓植物的传播相关。尽管保持了显着的整体减少，但所有泥炭藓类群在整个实验过程中都开始恢复，尽管在有S. warnstorfii的沼泽地中不太明显。去除泥炭藓可以逆转生物多样性的丧失，并允许在泥炭藓覆盖因轻微富营养化、酸化或地下水位下降而增加的肥沃沼泽中恢复棕色苔藓。在碱性和营养不良的条件下（例如，S. warnstorfii fens），效果明显且持续时间长，干预范围可能不大。在以S. teres或S. recurvum agg. 为主的沼泽地中，如果高养分可用性（钾、磷）或低碱度支持泥炭藓重新定殖，则可能需要重复或大规模清除。用S. subgenus Sphagnum处理的地块表现出最无希望的褐苔藓恢复前景。