Fen Meadows Research Articles

Habitat use by semi-feral Konik horses on wetlands—three-year GPS study

Free-ranging grazers are increasingly being introduced to areas of high natural value, such as wetlands. There is also growing attention that has been paid to the historical role of herbivores in shaping ecosystems and landscapes. Even though studies on the grazing of free-range horses were carried out in different regions and climates, still little is known about their habitat selection on heterogeneous marshy areas in the temperate region of Europe. The aim of this study was to investigate the habitat use by contemporary Konik horses during the growing season on the basis of three-year GPS data for a semi-feral herd kept on wetlands. Almost 68% of the occurrence of Konik horses were in open habitats. The assessment of habitat selection by the horses confirmed their strong preferences for grasslands on mid-forest dunes and forest avoidance. Konik horses somewhat preferred mowed fen meadows, but the animals displayed differences in the selection of habitat, probably depending on its humidity and weather conditions in a given year which may limit the role of grazing in protecting these communities. Horses need different habitats in wetlands such as fen meadows, forest, and grasslands on the mineral hills. This should be taken into consideration for landscape management in areas where the introduction of wild or semi-wild horse populations is planned.

The unexpected long period of elevated CH4 emissions from an inundated fen meadow ended only with the occurrence of cattail (Typha latifolia).

Drainage and agricultural use transform natural peatlands from a net carbon (C) sink to a net C source. Rewetting of peatlands, despite of high methane (CH4 ) emissions, holds the potential to mitigate climate change by greatly reducing CO2 emissions. However, the time span for this transition is unknown because most studies are limited to a few years. Especially, nonpermanent open water areas often created after rewetting, are highly productive. Here, we present 14 consecutive years of CH4 flux measurements following rewetting of a formerly long-term drained peatland in the Peene valley. Measurements were made at two rewetted sites (non-inundated vs. inundated) using manual chambers. During the study period, significant differences in measured CH4 emissions occurred. In general, these differences overlapped with stages of ecosystem transition from a cultivated grassland to a polytrophic lake dominated by emergent helophytes, but could also be additionally explained by other variables. This transition started with a rapid vegetation shift from dying cultivated grasses to open water floating and submerged hydrophytes and significantly increased CH4 emissions. Since 2008, helophytes have gradually spread from the shoreline into the open water area, especially in drier years. This process was periodically delayed by exceptional inundation and eventually resulted in the inundated site being covered by emergent helophytes. While the period between 2009 and 2015 showed exceptionally high CH4 emissions, these decreased significantly after cattail and other emergent helophytes became dominant at the inundated site. Therefore, CH4 emissions declined only after 10 years of transition following rewetting, potentially reaching a new steady state. Overall, this study highlights the importance of an integrative approach to understand the shallow lakes CH4 biogeochemistry, encompassing the entire area with its mosaic of different vegetation forms. This should be ideally done through a study design including proper measurement site allocation as well as long-term measurements.

The Influence of Konik Horses Grazing and Meteorological Conditions on Wetland Communities

Extensive management is one of the methods used in the conservation of fen meadows. The aim of the study was to characterize grassland communities grazed by Konik horses in the Biebrza National Park and to assess the influence of short-term grazing on the sward. During a 3-year period, phytosociological studies, measurements of the sward cover and height, as well as an assessment of the botanical composition of meadows were conducted in places grazed and excluded from grazing. The grasslands were mowed once a year at the turn of July and August, with the exception of mid-forest meadows. The area studied was dominated by communities of the Molinion alliance. Horses kept at a very low stocking rate reduced the height and cover of the sward. In the short-term, weather conditions, especially the duration of floods, had an even greater impact on the species composition of communities than grazing. Therefore, in order to protect the Molinia meadows, apart from extensive mowing, it is necessary to maintain appropriate habitat conditions, especially in terms of controlling the moisture, and conduct its regular monitoring.

Distribution, ecology and conservation of Aeshna caerulea (Ström, 1793) and Aeshna subarctica elisabethae Djakonov, 1922 (Insecta: Odonata) at the southernmost limits of their range

We provide an overview of the distribution, habitat preference, phenology, and conservation of Aeshna caerulea (Ström, 1793) and Aeshna subarctica elisabethae Djakonov, 1922 in Italy. Both species are found exclusively in the Central Eastern Alps. By 2021, A. caerulea has been reported for 31 sites, whereas A. s. elisabethae for 15. The new southernmost global range limit for A. caerulea was found in the Adamello massif and the new southernmost Western Palearctic limit for A. s. elisabethae in the Tesino plateau (Trentino-Alto Adige). Aeshna caerulea reproduces at high-altitude ponds or small lakes, inundated fens or fen meadows, and occasionally in the depressions within raised bogs. Aeshna s. elisabethae is found at lower altitudes, only at raised bogs and, to a lesser extent, in acidic transitional mires rich in Sphagnum mosses. Forty-six per cent of the reproduction sites of A. caerulea and 93% of those of A. s. elisabethae are included within a national/local protected area or the Natura 2000 network.

Mowing and disturbance increase survival rates of three rare moss species of fen meadows

Mowing and disturbance increase survival rates of three rare moss species of fen meadows

How to remove expansive perennial species from sedge-dominated wetlands: results of a long-term experiment in lowland river valleys

Grasslands belong to valuable ecosystems facing, all over Europe, a drastic decline in their range and loss of species diversity. Severe floristic transformation may result from the cessation of traditional low-input agricultural use, and consequently, the massive spread of perennial herbs and tall grasses. Invaders can quickly form dense stands and displace endemic vegetation, which results in a nearly complete turnover of phytocenoses. In European protected areas, the only legally acceptable means for suppressing alien species and native dominants within protected areas are biological methods and mowing. We investigated the effect of cutting on the presence of three megaforbs: Lysimachia vulgaris, Lythrum salicaria, and Filipendula ulmaria in fen meadows. We hypothesized that long-term, systematic management mimicking a traditional agricultural practice, would suppress the expansion of megaforbs. Management effectively stopped Lysimachia vulgaris only in marshes, where groundwater in the growing season fell deeper than 50 cm. Coverage of Lythrum salicaria fluctuated over the years, while Filipendula ulmaria did not give in to mowing pressure; on the contrary, it increased its coverage in some places. In light of the results of the long-term experiment, we conclude that mowing appeared to be low effective in preventing the spread of tall perennials. It was likely that indirect factors caused the local withdrawal of megaforbs, i.e., mowing-driven stimulation of other species’ development (e.g., Carex spp., Phragmites) that outcompete Lysimachia vulgaris.

×Pseudorhiza bruniana a Hargitán

Közleményemben röviden beszámolok a ×Pseudorhiza bruniana (Brügger) P.F.Hunt (Dactylor­hiza maculata (L.) Soó × Pseudorchis albida (L.) Á. Löve & D. Löve) egyet­len egyedének felfedezéséről a Hargita egy láprét­jén. A hibridnek ez az első adata Romániá­ból, egyben Közép-Európából.

Benefits of conservation-driven mowing for the EU policy species Gladiolus palustris Gaudin in mountain fen meadows: a case-study in the European Alps

The sword lily Gladiolus palustris Gaudin is protected on European level and listed in Annexes II and IV of the EC Habitat Directive 92/43/EEC. It grows in nutrient-poor, calcareous meadows in central and eastern Europe. Tree encroachment in montane meadows of the European Alps as a result of recent land use changes and the abandonment of traditional farming practices threaten the survival of this species. Conservation-driven mowing is considered a feasible conservation measure for maintaining high species diversity in abandoned semi-natural grasslands. To assess the effects of ten years of biennial mowing on a grassland community in the Dolomiti Bellunesi National Park, Italy (Site of Community Importance, Natura 2000 network), ten 25 m2 plots were established whereby four plots were placed in the mowed area, four in the non-mowed area and two in a small non-mowed patch of grassland inside the mowed area. In each plot the following variables were recorded, total percentage of plant cover, percentage cover of woody species, percentage cover of herbaceous species, percentage cover and number of flowering ramets of G. palustris and a complete list of species and their percentage abundance. Mowed plots showed a higher species richness than non-mowed plots. The number of G. palustris flowering ramets and percentage cover increased manifold in mowed plots compared to non-mowed plots. The resumption of mowing for conservation purposes undertaken by the managing authority halted the process of tree encroachment and avoided a drastic change in plant composition. Periodic mowing (every second or third year) was demonstrated to be a cost-effective conservation measure in non-productive grasslands to keep grasses at bay in favour of forbs of high conversation value.

Smouldering fire in a nutrient-limited wetland ecosystem: Long-lasting changes in water and soil chemistry facilitate shrub expansion into a drained burned fen

Wildfires are natural phenomena which regulate functioning and stability of fire-adapted ecosystems. However, their occurrence may impair the functioning of fire-susceptible ecosystems by disturbing nutrient cycling and biodiversity. This work aimed to identify environmental factors shaping post-fire patterns of shrub expansion in a drained, burned peatland. This research was conducted in a fire-susceptible drained rich fen, located in Biebrza National Park (Poland), which was subjected to a large-scale smouldering fire in 2002. In 2014, water and soil chemistry were studied alongside with foliar nitrogen (N), phosphorus (P) and potassium (K) contents of a native shrub (Salix cinerea) in four vegetation types present after the fire. Unburned areas were dominated by herbaceous plants. Willows present were sparse and low, with chloroses and necroses. Their foliar nutrient content indicated strong K limitation. Moderately burned areas were dominated either by willows or nitrophilous plants. Willows in moderately burned areas had high chlorophyll content in leaves and their foliar nutrient content indicated a lack of evident nutrient limitation. In the moderately burned areas, relatively high contents of phosphates (P-PO43−) were recorded in soil and water. In areas with high fire severity, willows were withdrawing and their foliar nutrient content indicated N limitation. Decreased content of P-PO43− and ammonium (N-NH4+) in soil and water was also observed there. Thus, fire-induced changes in fen geochemistry were recorded twelve years after a disturbance which shaped the long-term dynamics of shrub expansion. The fire ceased K limitation in burned areas and increased P availability. Strong K limitation, which is typical in degraded fens, appeared to be critical for keeping unmanaged fen meadows with low shrub cover. The occurrence of strong K limitation in drained fen ecosystems may reduce the need for investment in conservation practices used to restrict shrub expansion (e.g. regular mowing or shrub removal).

Germination requirements of the subordinate fen meadow species Valeriana dioica L

Plant species of the intermediate life strategy type are characteristic for species-rich grasslands, which are sensitive to changes in the level of disturbance. Germination and early establishment of seedlings is expected to be the most crucial stage, limiting the successful colonization of appropriate sites. Valeriana dioica is a typical plant of calcareous fens, which are dependent on regular suppression of strong competitors by means of moderate land use. It is endangered in many parts of Central Europe, including Lower Austria. We studied the effects of light, temperature and pre-treatment (cold stratification) on the germination success of V. dioica seeds and the role of litter produced by different competitors on the early establishment of seedlings. We tested seeds from five populations differing in the level of competition for light and considered also the morphological variability of propagules and maternal plants. We found that V. dioica is able to germinate without light. It showed high germination percentages both under high summer temperatures independent of cold stratification and at low temperatures, but only after the stratification. Litter produced by dicotyledonous forbs was less hampering for the seedlings than that of small sedges or grasses. Valeriana dioica possesses a broad regeneration niche and is able to use gaps for germination and establishment both in spring and in summer. It reproduces successfully in herb-dominated fen meadow vegetation but disappears from reed communities. This study demonstrates the significant plasticity of the regeneration niche for a species with an intermediate life strategy and also stresses the importance of gaps for its reproduction.

Effects of uncut hay meadow strips on spiders

Standard management of Czech hay meadows consists of machine mowing twice a year, with the first mowing in or before mid-June and the second mowing 40–60 days later. Here, we aimed to analyse the effects of the first year of implementation of the agri-environment scheme (AES), which consisted of allowing 3–10% of permanent grasslands within each land block to remain unmown until at least August 15, on the abundance and diversity of spiders. We conducted the study at 40 paired sampling sites in three meadow types in northern Czechia. Spiders were sampled using pitfall traps and sweeping, and the plant cover and vascular plant species composition were analysed. Nearly all study sites were associated with 100% vegetation cover, and hosted 209 vascular plant species, of which 12 were threatened. The number of vascular plant species exhibited only modest differences between the study sites under standard and AES-prescribed management. We captured a total of 3889 individuals of 103 spider species. The abundance of spiders was three-times higher at sites subjected to AES management. The number of species was similar irrespective of the management applied, but the species composition differed in response to the management (Sorensen index 0.562–0.736). The AES management was associated with higher abundance of common vegetation-dwelling farmland spiders, but epigeic spiders decreased there or were insensitive to AES management. It remains to be investigated whether threatened vegetation-dwelling spiders may benefit from similar AESs at sites of their occurrence, such as in fen meadows or steppes.

Ditches as species‐rich secondary habitats and refuge for meadow species in agricultural marsh grasslands

AbstractQuestionsCan drainage ditches in agricultural marsh grassland provide a suitable habitat for the persistence of fen meadow species? How does the ditch margin vegetation develop as a function of regular dredging? Is ornithologically oriented management also beneficial for plant biodiversity?LocationRiparian marshes, Eider‐Treene‐Sorge lowland, Schleswig‐Holstein, Germany.MethodsWe performed vegetation surveys of drainage ditches along with their water body, slope and margin structures annually for 3 years. The data were analysed with respect to date and means of ditch dredging. In addition, we recorded vegetation of the surrounding agricultural grassland, measured nutrient status of the soil and the water body and sampled seed bank of the ditch slopes. We used ANOVA and multivariate methods to describe the development of the ditch vegetation and the persistence of target meadow species.ResultsVegetation re‐development of ditch margins proceeds quite rapidly after disturbance from dredging. Dominance of mudbank species was observed only in the first year, followed by an increase of reed species and reduction of phytodiversity. Target species of wet meadow communities reach highest abundance in the second and third year and build a significant seed bank before being suppressed by reeds.ConclusionsIn heavily eutrophicated, intensively used marsh grassland, regularly disturbed ditch margins are important secondary habitats for pioneer and subdominant wetland species, which have nearly disappeared in a larger area. Current management cycles of ditch dredging every 3–4 years comply with the successional development, allowing the mudbank and wet meadow species to persist in the vegetation and seed bank. In contrast to the frequency, the form of dredging (ditch profile), which is crucial for bird protection, plays a minor role for plants. We recommend moderate disturbance (mowing of ditch margins) to suppress strong competitors in the years between dredging for additional support to target plant species.

Changing soil legacies to direct restoration of plant communities.

It is increasingly acknowledged that soil biota may influence interactions among plant species; however, little is known about how to change historical influences of previous land management on soil biota, the so-called 'biotic soil legacy effect'. We used a two-phase plant community-soil feedback approach to study how plant species typical to original (i.e. undisturbed) and degraded fen meadows may influence effects of the soil community on Carex species that are dominant in fen meadows. In phase 1, soil from original, degraded, successfully and unsuccessfully restored fen meadows was conditioned by growing plants typical to original or to degraded fen meadows. In phase 2, interactions between Carex and neighbouring plant species were studied to quantify plant community-soil feedback effects in different neighbour plant mixtures. Soil conditioning with plants typical to original fen meadows resulted in significantly more Carex biomass than with plants typical to degraded fen meadows. These effects were strongest when the soil originated from unsuccessfully restored fen meadows. However, biomass of plants typical of degraded fen meadows was also higher in soil conditioned by typical fen meadow plants. We conclude that soil legacy effects of plants from degraded fen meadows can be altered by growing typical fen meadow plant species in that soil, as this enhances priority effects that favour growth of other typical fen meadow plants. As also plant species from degraded fen meadows benefitted from soil conditioning, further studies are needed to reveal if plant species can be chosen that change negative soil legacy effects for rare and endangered fen meadow plant species, but not for plant species that are typical to degraded fen meadows.

Fen meadows on the move for the conservation of Maculinea (Phengaris) teleius butterflies

In the Netherlands, a single population of the obligate myrmecophilic butterfly Maculinea (Phengaris) teleius has survived on only 3 ha of habitat for more than 25 years, whereas at least 40 ha of habitat are thought to be required for a sustainable metapopulation. Therefore, 170 ha of farmland is being restored to wet meadows within a LIFE + project by large-scale soil excavation and hay inoculation. For successful restoration, the habitat requirements of the butterfly, with Sanguisorba officinalis as host plant and its particular life cycle as parasite of the ant species Myrmica scabrinodis, have to be taken into account. We tested whether colonization of nests of this ant species in the restoration areas is facilitated by translocation of sods collected from fen meadows. We divided 54 sods, each sized 1 m2, randomly over six patches and measured vegetation development and ant presence in the sods and surrounding control plots for 2 years. In the first summer, significantly more Myrmica ants were found in the transplanted sods in comparison to the surrounding area. Herb cover had a significant positive effect on Myrmica ant presence while it did not affect the presence of the pioneer ant species Lasius niger. In the second year, Myrmica ants were found in the surrounding control plots as well. This study contributes to the knowledge-base required for the design of restoration projects aimed at expanding the habitat of the critically endangered butterfly Maculinea (Phengaris) teleius.

Maintain Spatial Heterogeneity, Maintain Biodiversity—A Seed Bank Study in a Grazed Alpine Fen Meadow

AbstractWetland degradation is a source of anxiety and is more severe in cold regions than other areas. The soil seed bank acts as a propagule source for revegetation to affiliate the restoration of degraded wetlands. However, the effects of this approach are controversial and depend on the traits of the seed bank and its interactions with the environment. The seed bank in an alpine fen meadow was studied to determine its exact role in revegetation. The surveyed shore of a Tibetan lake, Gahai Lake, was divided into three sites under different levels of grazing pressure. Each site was separated into six transects along a water‐depth gradient to collect soil cores to determine the pattern of biodiversity through a germination experiment in a greenhouse. After an analysis of heterogeneity‐related diversity, partitioning of 58 discovered species indicated that 39.5 could be contributed to beta‐diversity, which was mainly contributed to water depth. Overgrazing (0.607 sheep unit/acre, November—March) decreased seed bank diversity in many respects, especially through decreasing spatial heterogeneity and homogenizing biota. A lightly grazed, well‐protected site had not only the highest beta‐diversity and species abundance but also the highest inter‐site species turnover rate compared with other sites under moderate grazing intensity. Despite the lack of target species, the seed bank serves as (i) a species‐rich pool; (ii) an extant legacy seed source for sustaining heterogeneity and floristic diversity; and (iii) an ecological indicator, and its effect can be reinforced by appropriate grazing practices (multiple intensity) and hydrological modifications. Copyright © 2016 John Wiley & Sons, Ltd.

Impact of land‐use intensity on the relationships between vegetation indices, photosynthesis and biomass of intensively and extensively managed grassland fens

AbstractVegetation indices are widely used as model inputs and for non‐destructive estimation of biomass and photosynthesis, but there have been few validation studies of the underlying relationships. To test their applicability on temperate fens and the impact of management intensity, we investigated the relationships between normalized difference vegetation index (NDVI), leaf area index (LAI), brown and green above‐ground biomass and photosynthesis potential (PP). Only the linear relationship betweenNDVIandPPwas management independent (R2 = 0·53).LAItoPPwas described by a site‐specific and negative logarithmic function (R2 = 0·07–0·68). The hyperbolic relationship ofLAIversusNDVIshowed a high residual standard error (s.e.) of 1·71–1·84 and differed between extensive and intensive meadows. Biomass andLAIcorrelated poorly (R2 = 0·30), with high species‐specific variability. Intensive meadows had a higher ratio ofLAIto biomass than extensive grasslands. The fraction of green to total biomass versusNDVIshowed considerable noise (s.e. = 0·13). These relationships were relatively weak compared with results from other ecosystems. A likely explanation could be the high amount of standing litter, which was unevenly distributed within the vegetation canopy depending on the season and on the timing of cutting events. Our results show there is high uncertainty in the application of the relationships on temperate fen meadows. For reliable estimations, management intensity needs to be taken into account and several direct measurements throughout the year are required for site‐specific correction of the relationships, especially under extensive management. UsingNDVIinstead ofLAIcould reduce uncertainty in photosynthesis models.

Assessing habitat exposure to eutrophication in restored wetlands: Model-supported ex-ante approach to rewetting drained mires

A multi-model-based study was performed in order to unravel valuable fen meadow habitats' possible exposure to eutrophication, which is expected to occur as a result of the re-saturation of degraded peat soils. The framework was tested in a 3000-ha fen-drain system to be restored in the Middle Biebrza Basin (northeast Poland), where the datasets and related models were used to delineate prospective eutrophication hotspots and nutrient transport. A 1-d hydrodynamic model and a 3-d groundwater flow model were applied to constitute the hydrological response of the fen-drain system to the prospective construction and function of weirs and spillways, which are expected to induce the increase of groundwater levels in degraded fens. A groundwater particle-tracking postprocessor was applied to delineate flow pathways and discharge zones and to determine water residence time in modelled layers. Soil and habitat maps, a high-resolution digital elevation model and historic groundwater level observations were applied to the model performance, calibration and spatial analysis of prospective eutrophication hotspots where increased eutrophication of groundwater can be expected due to the re-saturation of degraded peat soils. The study revealed that the large-scale fen rewetting that occurred as a result of surface water bodies' damming can potentially result in groundwater-driven nutrient dispersion along with an enhanced nutrient transport from a fen to the adjacent water bodies. Spatial analyses showed that, although the rewetting-driven eutrophication of Molinia fen meadows located in the study area is not likely, one can expect increased nutrient discharges to adjacent drains, inducing the contamination of ox-bow lakes located along the rivers. We propose the presented methodology to be applied ex-ante to fen-rewetting projects in strategic environmental assessments of restoration projects in order to manage the potentially negative environmental consequences of fen and river eutrophication with special regard to nutrient hotspots that are likely to occur within the rewetted fens.

Effect of reintroduced manual mowing on biodiversity in abandoned fen meadows

AbstractWetlands have recently become of high environmental interest. The restoration effects on habitats like fens are one of the main topics of recent restoration ecology, especially due to their interconnection with other ecosystems. We studied the manual mowing effect on abandoned fen using the response of three study taxa: diurnal butterflies, flower-visiting beetles and vascular plants. Our results showed that butterflies seems to be quickly-responding indicator taxon for evaluation and that restored management had a positive effect on both species richness and composition of this insect group. The results indicated that the manual mowing effect could be rapid. In comparison with the surrounding landscape, we found that: (i) the manually mowed site was most similar to strictly protected area, (ii) some species of high conservation value could reach higher abundance in restored than protected site, and (iii) manual mowing could bring a new type of habitat (i.e., spatial heterogeneity) compared to the other management types (abandonment, conservation and agri-environmental mowing). The main implication seems to be optimistic for practice: The manual mowing of long-term abandoned fen is leading to the creation of habitat with high conservation value in a relatively short time.

Multiple limitations to the persistence of Trollius europaeus in a fragmented agricultural landscape in the context of metapopulation theory

The knowledge about determinants of species survival is fundamental in conservation. Beyond determinants affecting local population survival, metapopulation theory emphasises the importance of processes operating on larger spatial scales (e.g. dispersal). We studied dispersal capacity and requirements for seedling recruitment of the threatened fen grassland species Trollius europaeus in order to assess the species’ ability to persist under the current land use conditions in the study region, north-east Germany. We used a seed sowing experiment and simulated endozoochorous and hydrochorous dispersal in a field and a laboratory experiment. Germination success reflected the experimental reduction of vegetation complexity, but the germination and recruitment rate was overall low. Survival was followed 2008–2011 and was best on plots with an intact moss layer. Mollusc exclusion displayed no significant effect. Endozoochorous dispersal is possible, however, in only minor quantities. Hydrochorous dispersal is very limited and negligible for connecting distant patches. We found evidence for microsite limitation, remnant population dynamics and the existence of unoccupied but suitable habitat patches available for colonization in our study region. However, (re-)colonization events are probably very rare due to dispersal limitation stressing the need for artificial seed transfer within the scope of restoration projects. Therefore, large quantities of seed material should be used in combination with mowing and thorough litter removal but leaving the moss layer intact. Management should be continued for longer than just the introduction year. Our study contributes to the understanding of species dynamics in fragmented landscapes. In particular, it contributes to the conservation of T. europaeus as an indicator of species-rich fen meadows in its Central European range.

Understanding long‐term effects of topsoil removal in peatlands: overcoming thresholds for fen meadows restoration

AbstractQuestionsWhat are the long‐term results of fen meadow restoration after topsoil removal on peatlands? What are the causes of slow fen‐meadow vegetation recovery on peat soils after topsoil removal?LocationDrentsche Aa Nature Reserve (53°00′49″N, 6°37′46″E) in the northeast Netherlands, with extensive natural and partially restored fen meadows (ca. 10,000 ha).MethodsRestoration measures consisted of removal of acidified and fertilized topsoil and improvement of local hydrology by blocking or removing drainage ditches. The effects of shallow (20 cm) and deep (40 cm) topsoil removal were compared. We monitored vegetation changes after restoration measures in permanent plots over a 13‐yr period, and analysed changes in species composition over time with ordination techniques (multivariate analysis: PCA and RDA). Soil conditions over time were analysed using repeated measures ANOVA.ResultsThe vegetation and environment shifted over time in response to restoration. At first the vegetation stagnated in a species‐poor phase for 5 yr, but eventually fen‐meadow species re‐established. At the end of the observation period, after 14 yr, the vegetation after both shallow and deep peat removal was similar. Soil acidification occurred immediately after topsoil removal (within the first 2–3 yr) due to pyrite oxidation when the soil was exposed to air after site excavation and the peat was temporarily desiccated.ConclusionsWe found poor re‐establishment of fen‐meadow vegetation and persistence of species‐poor communities during the first 5 yr after topsoil removal, probably resulting from internal soil acidification. After further rewetting, a rapid shift towards the target community composition was observed. The positive shift in development of fen‐meadow vegetation probably occurred due to increased groundwater discharge after successful hydrological measures were applied. Appropriate hydrological conditions (strong discharge of groundwater) are important for the success of restoration of these fen meadows, especially if pyrite is present in shallow soil layers.