Singh Patrícia, Hájková Petra, Jiroušek Martin, Lizoňová Zuzana, Peterka Tomáš, Plesková Zuzana, Šímová Anna, Šmerdová Eva, Štechová Táňa, Hájek Michal
Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic.
Department of Paleoecology, Institute of Botany, The Czech Academy of Sciences, Brno, Czech Republic.
Ecol Appl. 2022 Dec;32(8):e2691. doi: 10.1002/eap.2691. Epub 2022 Aug 4.
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 km 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.
富营养化草甸的不期望的连续演替会导致密集的泥炭藓地毯形成，这些地毯会胜过棕色苔藓和一些维管植物，从而导致具有高度保护重要性的草甸栖息地生物多样性丧失。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（即养分有效性）。因此，表征pH值和肥力水平的影响可能有助于制定更好的泥炭藓去除策略。在一个从波希米亚地块到西喀尔巴阡山脉（欧洲）、面积约32,000平方公里的区域内，对24个不同碱度和肥力的富营养化草甸进行了两项实验。我们假设高碱度和低肥力有利于去除泥炭藓后富营养化草甸植被的恢复。我们的研究集中在四个不同的泥炭藓组。在实验1中，处理地块没有围栏。在实验2中，处理地块被围栏隔开，并从周围环境移植目标棕色苔藓以克服扩散限制。采用重复测量设计，在5年期间记录植被组成。高碱度而非肥力促进了物种丰富度和目标棕色苔藓的出现。高碱度通常会阻碍泥炭藓的恢复，而高肥力则支持圆叶泥炭藓和卷叶泥炭藓复合体的再次出现。在高pH条件下，肥力增强进一步与低保护价值的非泥炭藓类苔藓植物的扩散相关。尽管总体上有显著减少，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 Warnstorf 泥炭藓的草甸中恢复不太明显。去除泥炭藓可能会扭转生物多样性丧失的局面，并使因轻微富营养化、酸化或地下水位下降而导致泥炭藓覆盖增加的富营养化草甸中的棕色苔藓得以恢复。在碱性和贫营养条件下（例如 Warnstorf 泥炭藓草甸）效果明显且持久，干预可能不需要广泛进行。在以圆叶泥炭藓或卷叶泥炭藓复合体为主的草甸中，如果高养分有效性（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去除。具有泥炭藓亚属的处理地块显示出棕色苔藓恢复前景最不乐观。
