Peatlands are globally important ecosystems that cover only around 3% of the Earth’s land surface; however, they store nearly one-third of the world’s soil carbon (United Nations Environment Programme [UNEP], 2022). This exceptional capacity results from the accumulation of partially decomposed organic material under persistently wet, oxygen-poor conditions, which slows microbial activity and allows carbon to build up over time (Craft, 2015).
Beyond carbon storage, peatlands provide a range of ecosystem services, including water regulation, nutrient retention, and support for specialized biodiversity (Joosten & Clarke, 2002; Tanneberger & Wichtmann, 2011). Their stable hydrological regimes help mitigate floods and droughts, while their organic soils are suitable for distinctive plant and animal communities. Peatlands also serve as valuable witnesses of historical nature development and are a part of local cultural heritage.
Despite these values, many peatlands across Europe have been drained and degraded due to agricultural expansion, forestry, and peat extraction (Joosten, 2009). Widespread drainage for peat mining and land use conversion has led to a loss of the acrotelm (the active peat-forming layer) and disrupted hydrological conditions and has triggered long-term carbon emissions (Leifeld & Menichetti, 2018). As an example, peat extraction has affected 4.2% of the raised bogs in the Baltic States (Hofer et al., 2012; Karofeld et al., 2016). The European Union’s consumption of peat has drawn criticism for its unsustainable nature and lack of long-term resource management strategies (Patel et al., 2025). The cessation of peat extraction without subsequent restoration efforts can lead to the collapse of the peatland ecosystem, with degraded sites often remaining drained, resulting in continued peat decomposition, subsidence, and impaired vegetation recovery (Rydin et al., 2013). Natural recovery and regeneration of associated peatland vegetation is typically limited by persistent low water levels, altered nutrient regimes, and vegetation shifts toward non-peat-forming species (Boers et al., 2006; Manton et al., 2021). Although spontaneous tree colonization may stabilize the soil, it does not restore natural ecosystem processes and functions of peatland and thus may, in fact, increase greenhouse gas (GHG) emissions (Craft, 2015; Kamocki et al., 2025). In managed but continuously drained peatland forests, carbon accumulation in biomass and litter input does not compensate for carbon losses(Mander et al., 2024). Afforesting drained peatlands also fails to reestablish their native biodiversity and ecological functions (Haapalehto et al., 2017; Jurasinski et al., 2024). Moreover, such interventions may increase the vulnerability of these landscapes to wildfires (Kohlenberg et al., 2018; Zheng et al., 2023).
Recognizing the climate and ecological impacts of peatland degradation, the European Union has placed restoration at the core of several key policy instruments. The EU Biodiversity Strategy for 2030, the Soil Strategy, and the Nature Restoration Law all identify the rewetting of drained peatlands as a critical measure for meeting climate and biodiversity goals (Communication COM/2020/380, Communication COM/2021/699, Regulation (EU) 2022/869). Regulation (EU) 2018/841 highlights the importance of restoring organic soils, including peatlands, to enhance carbon removals in the land-use sector. Recent studies have emphasized that afforestation of drained peatlands, in the absence of hydrological restoration, is unlikely to deliver climate benefits and may even exacerbate GHG emissions (Jurasinski et al., 2024; Mander et al., 2024). Instead, rewetting and ecological restoration, such as through paludiculture or the reintroduction of peat-forming vegetation, are increasingly recognized as effective nature-based solutions (Wichmann & Nordt, 2024).
In this study, we assess the ecological condition and restoration potential of abandoned peat extraction sites in Lithuania. Focusing on forested postextraction peatlands, we quantify peat volume loss, hydrological alterations, and associated carbon emissions. By evaluating degradation levels and the extent of ecosystem service loss, we aim to support site-specific restoration strategies that align with EU policy objectives. Our findings provide a basis for targeted rewetting efforts to reduce GHG emissions, improve ecological function, and contribute to national and European peatland restoration commitments.
Peatlands are an integral component of Lithuania’s landscape, covering approx. 640,000 ha (10% of the country), and represent one of the country’s most hydrologically and ecologically significant ecosystems (Valatka et al., 2018). Based on their geological origin and trophic status, peatlands in Lithuania comprise three main types: fens (78%), minerotrophic systems fed by mineral-rich groundwater, surface runoff, and precipitation; raised bogs (8%), oligotrophic peatlands elevated above the surrounding terrain and sustained purely by precipitation; and transitional mires (14%), which exhibit intermediate characteristics of both fens and bogs (Mitsch & Gosselink, 2015; Manton et al., 2021).
Historically, peat extraction has played a major role in the rural economy, beginning in the early 20th century and expanding rapidly during the Soviet industrial period (1950–1990) (Paavilainen & Päivänen, 1995). Currently, approx. 70% of Lithuania’s peatlands have been drained and show evidence of human disturbance (Jarašius et al., 2015; Valatka et al., 2018). In total, peat extraction sites cover 20,533 hectares of which 60% are overgrown by secondary forests (Grigaliunas et al., 2023). The abandonment of drained and or extracted peatlands generally undergo spontaneous succession, typically colonized by pioneer woody species such as Betula pubescens, Pinus sylvestris, and Salix spp., resulting in the formation of secondary forests with altered hydrological regimes (Manton et al., 2021; Jarašius et al., 2022). Although these peatlands are degraded, they provide valuable opportunities for understanding hydrological recovery, vegetation succession, and ecosystem service restoration in peatland landscapes (Makrickas et al., 2023).
This study focuses on 33 abandoned peatland quarries (3,854 ha) in Lithuania, Northern Europe (Fig. 1).
Distribution of abandoned peatlands in the territory of the country and location of the areas investigated during field research
Source: own work.
To identify and characterize degraded peatlands in forested areas across Lithuania, we first conducted a GIS-based spatial analysis to identify the spatial components of the peatlands (i.e., location, area, elevation). We used data from three national data sources: the Lithuanian mire and peatlands database (Agricultural Data Center [ŽŪDC], 2025), the cadastral database (Lithuanian State Forest Service [VMU], 2021), and the Lithuanian database of biodiversity (Valstybinė saugomų teritorijų tarnyba prie Aplinkos ministerijos [VSTT], 2025). The selection of the 33 abandoned peatland quarries was based on the presence of historical peat extraction data, spatial representation throughout Lithuania and a range of ecological conditions (i.e., peatland type, peat depth, water level, vegetation type, woody biomass, etc.) (Fig. 2).
Three samples of abandoned peatland quarries showing the range of ecological conditions found in Lithuania
Source: photos by J. Sendžikaitė.
The representative 33 abandoned peatland quarries were selected for field investigations, which were conducted between 2022 and 2023. At each site, we assessed peat depth, soil acidity (pH), carbon-to-nitrogen ratio (C : N), water table level (depth), and wood volume to determine the condition of the abandoned peatlands.
Peat depth was measured by applying a minimum of 10 sampling points along a standardized 100 m sampling transect using a standard peat corer following national peat survey guidelines (Saulėnas, 1993). We collected three samples at each site from the upper peat layer (5–15 cm) for laboratory analysis. The samples were analyzed for pH (measured in a 1 : 2.5 peat–water suspension), total organic carbon (by wet oxidation or spectrophotometry), and total Kjeldahl nitrogen, allowing us to calculate the C : N ratio. Trophic status (oligotrophic, mesotrophic, or eutrophic) was estimated based on the C : N and vegetation composition, following the classification system of Succow and Stegmann (2001), while the degree of peat decomposition was assessed in the field using the von Post humification scale (H1–H10).
Water table levels were recorded at the same locations as the peat depth measurements, and we supplemented the water table levels with long-term data from automated loggers at five sites (Aukštumala, Sachara, Pūsčia, Plinkšiai and Užpelkiai). Based on Koska et al. (2001), we classified site moisture regimes into six categories, from dry to lower eulittoral. For analysis, we used a threshold depth of 35 cm below the surface. Sites with an average water table deeper than this were considered to have unfavorable conditions for natural peat formation and thus considered degraded.
The analysis of wood volume on abandoned peatland quarries can help assess ecosystem recovery and carbon sequestration, as tree biomass reflects post-extraction succession. Increased wood volume also indicates peatland degradation, such as drying or nutrient enrichment, making it a useful but context-dependent indicator of peatland condition (Makrickas et al., 2023). Therefore, we used the cadastral database (VMU, 2021) to estimate the tree wood volume for each of the 33 abandoned peatland quarries.
Using past statistics (Hammer, 2023) we normalized the five peatland characteristic data (peat depth, soil pH, C : N, water depth, and wood volume) and performed a multivariate principal component analysis (PCA) using a variance–covariance matrix. The PCA was performed to reduce the complexity of the dataset by transforming the five correlated environmental variables (C : N, pH, peat depth, water level and wood volume) into components that capture the main ecological gradients. We also performed a cluster analysis. These analyses produced a clearer visualization of site differences and identified key drivers like acidity, hydrology, and forest volume across peatland types.
To evaluate the extent of peatland degradation, we estimated the volume of peat loss by comparing current and presumed natural historical surface elevations prior to peat extraction for each of the 33 sites. The analysis combined vector data representing peatland boundaries with raster-based surface elevation data.
Polygons delineating peatland areas in a shapefile format were used. For each site, a digital elevation model containing values representing the current peat surface altitude in meters above sea level was defined. All spatial data were projected to the Lithuanian Coordinate System of 1992 (LKS-92) to ensure geometric compatibility.
To estimate the original peat surface before drainage or subsidence, we used a two-meter buffer ring around each polygon. The outer buffer (expanded by 2 m) and the inner buffer (contracted by 2 m) defined a ring-shaped area approximating the undisturbed rim. The mean elevation value within this rim was taken as the reference historical surface level. The current average surface elevation was then calculated using raster values within each peatland polygon.
The difference between historical and current averages provided an estimate of surface lowering and thus the loss of peat through both extraction and subsequent subsidence following abandonment. Subsequently, we used the average peat market price of €116 per ton (t) to estimate the carbon loss value of each of the 33 peatlands (IndexBox, 2025).
We applied the following equation to estimate the value of peat loss: value [€] = peat volume [m3] × bulk density [t⸱m−3] × price [€⸱t−1], where: bulk density is 0.1 t·m−3 and price is €116 per ton.
To estimate the reduction in water retention capacity, we assumed that the field capacity of peat is up to 80% of its volume in water (Holden, 2005). Thus, every cubic meter of peat lost corresponds to 0.8 m3 of water storage capacity lost. To provide an indicative economic value, we used a rate of €0.54 per m3 of water, based on benefit transfer values from regional studies (e.g., Stachowicz et al., 2022; Makrickas et al., 2023). This allowed us to estimate the value of lost hydrological services. We emphasize that these estimates are general and should be treated as indicative rather than site-specific.
Carbon loss from peat extraction was estimated by converting the volume of removed peat into dry mass, applying a carbon fraction, and expressing the result as both tons of carbon (t C) and carbon dioxide equivalents (t CO2) using the following equations (Intergovernmental Panel on Climate Change [IPCC], 2014):
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Peat mass [kg] was calculated as: Mpeat = V × ρpeat, where: V is peat volume [m3] and ρpeat is bulk density [kg·m−3].
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Carbon stock [t C] was then estimated as:
C = {{V \times {\rho _{{\rm{peat}}}} \times fC} \over {1,000}} - –
Carbon dioxide equivalents [t CO2] were derived as:
{\rm{CO}_2}\;{\rm{eq}}. = {{V \times {\rho _{{\rm{peat}}}} \times fC} \over {1,000\left( {{{44} \over {12}}} \right)}}
It should be noted that this mid-range approach assumes uniform peat properties across the extracted peat quarries, as site-specific variability in bulk density or decomposition state was not available. It also represents carbon removed as stock (Turetsky et al., 2015). This stock-based approach is widely applied in peatland carbon accounting when direct flux data are lacking (Gorham, 1991; Joosten & Clarke, 2002; Turetsky et al., 2015).
Finally, we used the average carbon dioxide emission market price of €57.24 (VICAP) (from 1 January 2024 to 5 September 2025) to estimate the carbon loss value of each of the 33 peatlands (International Carbon Action Partnership [ICAP], 2025).
Rewetting represents a fundamental initial phase of peatland restoration, undertaken to enhance the provision of ecosystem services and their contributions to human well-being (Stachowicz et al., 2022). In drained peatlands, this process is primarily achieved through the closure of anthropogenic drainage networks. Therefore, we estimated the cost (€2,400 per ha) to rewet the 33 abandoned peatland quarries, following Stachowicz et al. (2022) and Makrickas et al. (2023).
A total of 33 peatland sites (3,854 ha) were assessed, displaying a broad range of ecological conditions (Fig. 2). Despite historical peat extraction, all still contain at least 30 cm of peat and thus meet the formal definition of peatland. The mean peat depth varied from as little as 0.5 m (Saliečiai) to a maximum of 7 m (Užpelkiai), with the majority clustered around 2 m. This indicates that large volumes of peat are still present (Table 1).
The examination of water levels across 33 peatland sites indicates that the majority exhibit low hydrological conditions, with 14 sites (42%) falling into the lowest category, “2−”, suggesting considerable drainage. Intermediate water levels (categories “2+” to “3+”) are observed in 13 sites (39%), while only six peatlands (18%) demonstrate high water levels rated as “4+”. Notably, all sites with a water level of “4+” have been classified as being in satisfactory condition, and several have undergone restoration. Notably, peatlands such as Aukštumala, Plinkšė, Pūsčia, Sachara and Užpelkiai have undergone restoration, displaying higher water levels. This pattern suggests a clear relationship between restoration efforts and improved hydrological conditions, underlining the importance of active water level management in peatland conservation and carbon retention strategies (Table 1).
Soil acidity, measured as pH, ranged from very acidic (pH 2.73 in Plinkšiai) to near-neutral values (pH 7.00 in Girdijauskai), indicating diverse geochemical profiles. However, most pH samples were below 4.5, particularly in sites originally classified as raised bogs (Table 1).
The carbon-to-nitrogen ratio, a proxy for peat decomposition and quality, spanned from 20.6 (Paduobys) to 83.0 (Vadakstis), with higher values often associated with lower peat mineralization. Most sites also showed high C : N, suggesting low nutrient availability and slow decomposition. Peat decomposition ranged from weak (H3) in wetter areas to moderate or strong (H6–H7) in more degraded locations. Many samples fell in the H4–H5 range, which reflects ongoing aerobic decay due to low water tables (Table 1). Oligotrophic peatlands typically exhibit low pH values (< 4.2) and are dominated by acid-tolerant, nutrient-poor vegetation. Mesotrophic sites showed intermediate pH values (4.2–5.5) and supported a more diverse flora, including brown mosses and sedges (Jarašius et al., 2022). Eutrophic peatlands were identified by higher pH levels (> 5.5) and the presence of nutrient-demanding species such as Carex, Phragmites, and/or Typha. Together, these indicators provided insight into both the nutrient regime and the degree of peat decomposition at each site.
Aboveground woody biomass ranged widely, from 10.18 m3·ha−1 (Aukštumala) to 207.93 m3·ha−1 (Rūdgiris), reflecting both natural forest development and afforestation in some sites. Several sites in poor peatland condition (i.e., Sachara) were also recorded with high wood volumes. This raises concerns about the role of spontaneous tree encroachment in inhibiting restoration outcomes (Table 1).
Overview of the peatland characteristic of the 33 extracted quarries in Lithuania
| Peatland | Peatland type | Area [ha] | Mean peat depth [m] | pH | C : N | Water level | Wood volume [M3⸱ha−1] | Ecological condition | Restoration |
|---|---|---|---|---|---|---|---|---|---|
| Aukštoji plynė | raised bog | 190 | 2.0 | 3.29 | 53.1 | 2− | 124.82 | bad | |
| Aukštumala | raised bog | 66 | 2.0 | 3.06 | 55.0 | 3+ | 10.18 | satisfactory | yes |
| Bokštų – Klabų | fen / transitional mire | 48 | 2.0 | 3.55 | 47.2 | 2− | 90.76 | bad | |
| Burbonys | raised bog | 225 | 1.6 | 3.13 | 64.5 | 2− | 69.57 | bad | |
| Čelkiai | fen | 65 | 2.0 | 3.28 | 73.8 | 2− | 130.75 | bad | |
| Dabravolė | raised bog | 71 | 2.0 | 2.95 | 60.0 | 2− | 102.50 | bad | |
| Dainaviškiai | raised bog | 153 | 2.0 | 3.19 | 58.2 | 2+ | 206.96 | satisfactory | |
| Derkintai | fen / transitional mire | 75 | 2.0 | 6.05 | 25.0 | 4+ | 69.90 | satisfactory | |
| Didžlaukis | fen / raised bog | 63 | 1.4 | 3.03 | 72.8 | 2− | 63.07 | bad | |
| Dūčiai | fen / transitional mire | 185 | 0.7 | 5.62 | 27.3 | 2− | 64.65 | bad | |
| Ežerėlis | fen / transitional mire | 581 | 1.0 | 3.08 | 38.7 | 2− | 82.43 | bad | |
| Gaidukonys | fen | 26 | 2.0 | 3.28 | 42.9 | 3+ | 157.13 | satisfactory | |
| Garonys | raised bog | 80 | 2.5 | 3.04 | 70.3 | 2+ | 54.47 | bad | |
| Girdijauskai | fen | 84 | 1.8 | 7.00 | 20.7 | 3− | 17.79 | bad | |
| Januškiai | fen | 60 | 2.0 | 5.76 | 26.0 | 4+ | 75.75 | satisfactory | |
| Kašučiai | raised bog | 20 | 1.2 | 3.22 | 47.9 | 2− | 121.41 | bad | |
| Kaušanka | fen / raised bog | 88 | 2.0 | 4.39 | 56.0 | 2− | 110.20 | bad | |
| Kazimierava | raised bog | 19 | 2.0 | 2.82 | 56.1 | 3+ | 114.29 | satisfactory | |
| Laukagalis | raised bog | 144 | 1.7 | 4.48 | 46.9 | 2− | 75.38 | bad | |
| Leoniškė | raised bog | 52 | 1.4 | 3.35 | 72.1 | 4+ | 125.46 | satisfactory | |
| Mažieji Mostaičiai | fen | 10 | 1.0 | 3.74 | 23.8 | 3− | 148.50 | satisfactory | |
| Paąžuolynė | raised bog | 55 | 2.0 | 3.31 | 42.4 | 2+ | 119.32 | satisfactory | |
| Paduobys | fen | 268 | 1.5 | 5.56 | 20.6 | 2+ | 79.26 | satisfactory | |
| Plinkšė | raised bog | 70 | 2.0 | 2.73 | 68.2 | 3+ | 85.83 | satisfactory | yes |
| Pūsčia | raised bog | 87 | 6.0 | 3.56 | 52.2 | 3+ | 73.42 | satisfactory | yes |
| Raistapelkė | transitional mire | 44 | 2.0 | 5.56 | 23.3 | 4+ | 41.78 | satisfactory | |
| Raudonbalė | raised bog | 36 | 2.0 | 3.06 | 61.1 | 2+ | 114.87 | satisfactory | |
| Rūdgiris | raised bog | 21 | 2.0 | 3.34 | 32.6 | 2+ | 207.93 | satisfactory | |
| Sachara | raised bog | 93 | 1.5 | 2.84 | 62.1 | 3+ | 121.04 | satisfactory | yes |
| Saliečiai | fen | 345 | 0.5 | 4.37 | 39.7 | 2− | 94.42 | bad | |
| Sūsia | fen | 455 | 1.2 | 4.37 | 39.7 | 2− | 60.10 | bad | |
| Užpelkiai | raised bog | 17 | 7.0 | 3.55 | 37.6 | 4+ | 23.45 | satisfactory | yes |
| Vadakstis | raised bog | 58 | 2.0 | 3.45 | 83.0 | 3+ | 71.23 | bad | |
| Total area | 3,854 |
Source: own work.
Peatland condition was classified as “satisfactory” for 17 sites and “bad” for 16, suggesting that nearly 50% of sites remain heavily degraded with deep drainage, heavily decomposed peat, and dominance of non-peat-forming vegetation. This was supported by water level data, where most degraded sites exhibited a low water table (2−), potentially limiting peat-forming processes, increasing GHG emissions and forming unnatural mire vegetation communities. The 16 peatlands deemed satisfactory were nonetheless moderately degraded but retained patches of semi-natural vegetation or higher water levels. None of the sites were in a good or near-natural condition. Restoration measures were reported in only a few sites, notably Aukštumala, Plinkšė, Pūsčia, Sachara, and Užpelkiai, highlighting the limited but targeted application of rewetting efforts (Table 1). Both the least disturbed sites and rewetted sites require further active restoration efforts to recover peat-forming processes.
The results of the PCA analysis showed that the first two principal components (PC1 and PC2) accounted for a cumulative 67.83% of the total variance, with PC1 explaining 37.98% and PC2 explaining 29.85%. The remaining components contributed progressively less, with PC3, PC4, and PC5 explaining 17.68%, 10.66%, and 3.83%, respectively (Table 2).
PC1 was primarily associated with C : N (loading = 0.617) and pH (loading = −0.682), indicating a strong gradient between organic matter quality and acidity. PC2 was dominated by peat depth (0.702) and water level (0.618), reflecting hydrological and vertical structural variation across sites. PC3 was most influenced by wood volume (0.749), suggesting a link to forest biomass accumulation. The remaining components (PC4 and PC5) showed mixed contributions but were less influential in explaining overall variance (Table 3).
Summary result values from the principal component analysis
| PC | Eigenvalue | Variance [%] |
|---|---|---|
| 1 | 1.899 | 37.982 |
| 2 | 1.492 | 29.852 |
| 3 | 0.883 | 17.675 |
| 4 | 0.533 | 10.663 |
| 5 | 0.191 | 3.827 |
Source: own work.
Summary result values from the principal component analysis loading values
| Specification | PC1 | PC2 | PC3 | PC4 | PC5 |
|---|---|---|---|---|---|
| C : N | 0.617 | 0.023 | −0.423 | 0.312 | 0.584 |
| pH | −0.682 | 0.011 | 0.097 | 0.151 | 0.709 |
| Peat depth | 0.077 | 0.702 | −0.050 | −0.673 | 0.214 |
| Water level | 0.110 | 0.618 | 0.498 | 0.591 | −0.097 |
| Wood volume | 0.368 | −0.352 | 0.749 | −0.280 | 0.317 |
Source: own work.
The biplot (Fig. 3) illustrates the spatial distribution of the sampling sites and variable loadings. Sites with high C : N and low pH values were clustered along the positive axis of PC1, while deeper peat and higher water levels aligned with a positive PC2. Wood volume showed a strong association with PC3 and was orthogonal to the hydrological gradient, indicating distinct ecological drivers.
Overall, the PCA revealed clear separation among peatland types based on chemical, hydrological, and structural attributes, supporting the classification of peatland condition and guiding restoration prioritization.
Results from principal component analysis based on variance-covariance matrix analysis of 5 variables representing 33 peatlands in Lithuania
Source: own work.
Visual inspection of the dendrogram from the hierarchical cluster analysis (Fig. 4) revealed distinct groupings among the peatland sites based on environmental variables. The hierarchical cluster analysis identified four major groupings among the 33 peatland sites, based on environmental variables such as C : N, water level, peat depth and wood volume. Dividing the dendrogram at a linkage distance of approximately seven revealed the following clusters:
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Cluster 1 (9 sites): Includes Paduobys through to Sūsia peatlands (see: Fig. 4). These sites share similar topographic, hydrological and pH characteristics, likely representing moderately degraded peatlands with spontaneously revegetated vegetation.
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Cluster 2 (2 sites): The Pūsčia and Užpelkiai peatlands, characterized by relatively intact peatland conditions, with consistent water regimes and a deeper peat depth.
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Cluster 3 (8 sites): Includes the Dainaviškas – Leoniškė peatlands. These sites appear to occupy an intermediate ecological position, possibly reflecting mixed land use impacts and variable restoration potential with similar C : N and wood volumes.
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Cluster 4 (14 sites): Includes the Kašučiai – Garonys peatlands. These peatlands are more ecologically distinct, showing signs of advanced degradation and disturbed hydrological regimes with increased seasonal variability and impaired water retention capacity.
This four-cluster PCA result provides a clearer ecological stratification of the former peatland quarry sites, thus offering a valuable framework for prioritizing conservation and restoration efforts based on shared site characteristics (Fig. 4).
Results of the cluster analysis identified four main peatland clusters; from left to right, these represent clearer ecological stratification of the peatland sites
Source: own work.
The assessment of the 33 abandoned Lithuanian peatland sites subjected to peat extraction revealed significant peat removal, surface subsidence, and volume reduction (Table 4). The average surface lowering ranges from 0.03 m (Dainaviškiai) to 4.97 m (Paduobys), with a mean lowering of approx. 1.81 m. These vertical losses reflect the cumulative effects of mechanical extraction, drainage, and compaction over time. The resulting peat volume losses are substantial, with site-specific estimates ranging from 33,261 m3 (Mažieji Mostaičiai) to over 8.3 million m3 (Saliečiai). Major extraction sites such as Saliečiai and Sūsia have each lost more than 12 million m3 of peat, primarily due to their large surface areas and sustained extraction intensity. Collectively, the total peat volume loss across all surveyed peatlands exceeds 53.4 million m3, underscoring the extensive alteration of peatland morphology and carbon storage capacity resulting from industrial-scale extraction activities. In addition to direct removal, long-term drainage and peat oxidation have contributed to continued surface subsidence, a process typically occurring at rates of approx. 0.5–2.0 cm annually in peatlands (Grzywna, 2017; Oleszczuk et al., 2022; Ghezelayagh et al., 2024). However, given that the lowering in the analyzed sites reaches 4.97 m, this natural subsidence component represents only a minor share of the total vertical loss.
Peatland drainage and peat extraction lead to both physical removal of organic material and significant water volume loss, as peatland drainage lowers the water table and accelerates oxidation (Table 4). Across the 33 sites, estimated water volume losses range from 26.6 m3 (Mažieji Mostaičiai) to over 6.6 million m3 (Saliečiai). The total estimated water volume lost across all extraction sites is close to 62 million m3, reflecting both direct hydrological drainage and secondary subsidence impacts. These losses illustrate the extensive hydrological disruption caused by peat extraction and emphasize the need for post-extraction rewetting and ecological restoration to mitigate further degradation and re-establish peatland functions.
The analysis of the 33 abandoned peatland quarries revealed highly variable carbon losses and associated economic values (Table 4). Individual carbon stock losses ranged from as low as 5,355 t C at Leoniskė to over 666,352 t C at Paduobys. This carbon loss translates into a wide range of estimated carbon values, from €19,636 at Leoniskė to more than €139.9 million at Paduobys. These results underline both the scale of past carbon emissions and the significant potential economic value of restoring and conserving remaining peat carbon stocks.
The rewetting cost estimates for the 33 abandoned peatland quarries show large variation across sites, reflecting differences in areas and degradation extents (Table 4). The largest peatlands, such as Paduobys (2.67 million m2) and Plinkšė (3.5 million m2), have correspondingly high estimated rewetting costs of €642,948 and €1.06 million, respectively. In contrast, smaller peatlands such as Mažieji Mostaičiai (101,278 m2) and Kašučiai (19,583 m2) require far lower investments of only €24,307 and €34,575, respectively. Several medium-sized sites, like Burbonys (2.24 million m2) and Kazimierava (187,681 m2), show intermediate costs (€539,780 and €45,043, respectively). These results highlight how peatland size strongly influences the estimated financial needs for restoration through rewetting.
The analysis of 33 abandoned peatland quarries revealed substantial peat, water, and carbon loss (Table 4). Across a total surveyed area of 3.85 million m2, peat volume loss amounted to approx. 77.5 million m3, accompanied by a water volume loss of 61.9 million m3. The estimated carbon stock loss reached 3.87 million t C. This is equivalent to 14.2 million t CO2 emissions. In economic terms, the total value of peat loss was estimated at €898.8 million, with additional losses of €33.5 million in water and €813.1 million in carbon. The costs associated with rewetting all 33 abandoned peatland quarries were estimated at €9.25 million, resulting in a net balance of approx. €42.97 million. These results highlight both the magnitude of the historic degradation and the considerable potential benefits of restoration for climate mitigation and ecosystem service recovery.
It should be noted that the extrapolation of peat loss and subsidence is a complex task due to its nonlinearity (Ikkala et al., 2021) and the different subsidence dynamics in forested versus agricultural peatlands (Liu et al., 2020). Moreover, the analysis of ecosystem services only focused on the once-off loss of peat extraction and rewetting, but not the scale and accumulated losses since abandonment or benefits of rewetting. As an example, the abandonment of peatland ranged from 1940 to 2020, and some peatlands are under restoration. Thus, our general estimates are a transient process.
Estimated peatland extraction losses in terms of volume and monetary value for peat, water and carbon
| Peatland | Area [m2] | Average lowering [m] | Peat volume lost [m3] | Water volume lost [m3] | Carbon stock [t C] | CO2 eq. [t CO2] | Peat value [€] | Water value [€] | Carbon value [€] | Rewetting [€] | Balance [€] |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Aukštoji plynė | 1,897,398 | 0.99 | 1,884,403 | 1,507,522 | 94,220 | 345,477 | 21,859,073 | 814,062 | 19,775,104 | 455,376 | 814,532 |
| Aukštumala | 660,029 | 1.00 | 660,029 | 528,023 | 33,001 | 121,006 | 7,656,336 | 285,132 | 6,926,407 | 158,407 | 286,390 |
| Bokštų – Klabų | 479,576 | 0.50 | 239,788 | 191,830 | 11,989 | 43,962 | 2,781,541 | 103,588 | 2,516,358 | 115,098 | 46,496 |
| Burbonys | 2,249,084 | 2.68 | 6,020,396 | 4,816,317 | 301,020 | 1,103,749 | 69,836,588 | 2,600,811 | 63,178,605 | 539,780 | 3,517,392 |
| Dabravolė | 707,745 | 0.40 | 280,998 | 224,798 | 14,050 | 51,517 | 3,259,575 | 121,391 | 2,948,818 | 169,859 | 19,507 |
| Dainaviškiai | 1527519 | 0.03 | 4,8171 | 38,537 | 2,409 | 8,831 | 558,784 | 20,810 | 505,511 | 366,605 | −334,142 |
| Derkintai | 753,770 | 3.35 | 2,527,243 | 2,021,794 | 126,362 | 463,332 | 29,316,019 | 1,091,769 | 26,521,129 | 180,905 | 1,522,216 |
| Didžlaukis | 628,759 | 0.66 | 412,802 | 330,242 | 20,640 | 75,681 | 4,788,508 | 178,331 | 4,331,988 | 150,902 | 127,287 |
| Dūčiai | 1,854,022 | 2.36 | 4,379,285 | 3,503,428 | 218,964 | 802,876 | 50,799,706 | 1,891,851 | 45,956,635 | 444,965 | 2,506,255 |
| Ežerėlis | 5,809,552 | 0.60 | 3,485,731 | 2,788,585 | 174,287 | 639,057 | 40,434,482 | 1,505,836 | 36,579,596 | 1,394,292 | 954,758 |
| Garonys | 803,448 | 2.68 | 2,1503,21 | 1,720,257 | 107,516 | 394,229 | 24,943,727 | 928,939 | 22,565,676 | 192,828 | 1,256,284 |
| Geidukonys | 262,586 | 0.83 | 217,177 | 173,741 | 10,859 | 39,816 | 2,519,249 | 93,820 | 2,279,073 | 63,021 | 83,336 |
| Girdijauskai | 837,204 | 2.95 | 2,468,046 | 1,974,437 | 123,402 | 452,479 | 28,629,331 | 1,066,196 | 25,899,908 | 200,929 | 1,462,298 |
| Januškiai | 603,841 | 3.51 | 2,120,003 | 1,696,002 | 106,000 | 388,671 | 24,592,035 | 915,841 | 22,247,514 | 144,922 | 1,283,758 |
| Kašučiai | 198,535 | 0.62 | 122,455 | 97,964 | 6,123 | 22,450 | 1,420,478 | 52,901 | 1,285,054 | 47,648 | 34,875 |
| Kaušanka | 878,596 | 2.24 | 1,971,236 | 1,576,989 | 98,562 | 361,397 | 22,866,339 | 851,574 | 20,686,340 | 210,863 | 1,117,562 |
| Kazimierava | 187,681 | 3.15 | 591,366 | 473,093 | 29,568 | 108,418 | 6,859,844 | 255,470 | 6,205,850 | 45,043 | 353,481 |
| Laukagalis | 1,441,621 | 0.87 | 1,246,935 | 997,548 | 62,347 | 228,607 | 14,464,446 | 538,676 | 13,085,455 | 345,989 | 494,326 |
| Leoniškė | 521,081 | 0.21 | 107,104 | 85,683 | 5,355 | 19,636 | 1,242,406 | 46,269 | 1,123,959 | 125,059 | −52,882 |
| Mažieji Mostaičiai | 101,278 | 0.33 | 3,3261 | 26,609 | 1,663 | 6,098 | 385,828 | 14,369 | 349,044 | 24,307 | −1,892 |
| Čelkiai | 649,624 | 2.78 | 1,805,635 | 1,444,508 | 90,282 | 331,036 | 20,945,370 | 780,035 | 18,948,510 | 155,910 | 1,060,916 |
| Paąžuolynė | 552,464 | 2.61 | 1,443,053 | 1,154,443 | 72,153 | 264,562 | 16,739,416 | 623,399 | 15,143,537 | 132,591 | 839,889 |
| Paduobys | 2,678,952 | 4.97 | 13,327,034 | 10,661,627 | 666,352 | 2,443,312 | 154,593,594 | 5,757,279 | 139,855,166 | 642,948 | 8,338,201 |
| Plinkšė | 697,250 | 0.50 | 349,546 | 279,637 | 17,477 | 64,084 | 4,054,733 | 151,004 | 3,668,168 | 167,340 | 68,221 |
| Pūsčia | 871,503 | 3.46 | 3014,593 | 2,411,674 | 150,730 | 552,680 | 34,969,276 | 1,302,304 | 31,635,424 | 209,161 | 1,822,387 |
| Raistapelkė | 442,392 | 2.54 | 1,121,856 | 897,485 | 56,093 | 205,675 | 13,013,528 | 484,642 | 11,772,863 | 106,174 | 649,850 |
| Raudonbalė | 356,677 | 0.29 | 104,145 | 83,316 | 5,207 | 19,093 | 1,208,077 | 44,990 | 1,092,903 | 85,602 | −15,419 |
| Rūdgiris | 208,626 | 3.05 | 635,275 | 508,220 | 31,764 | 116,468 | 7,369,194 | 274,439 | 6,666,640 | 50,070 | 378,045 |
| Sachara | 925,314 | 0.87 | 801,704 | 641,363 | 40,085 | 146,980 | 9,299,763 | 346,336 | 8,413,155 | 222,075 | 318,196 |
| Saliečiai | 3,446,981 | 3.48 | 11,995,418 | 9,596,335 | 599,771 | 2,199,180 | 139,146,849 | 5,182,021 | 125,881,061 | 827,275 | 7,256,492 |
| Sūsia | 4,552,531 | 2.42 | 11,040,897 | 8,832,718 | 552,045 | 2,024,183 | 128,074,405 | 4,769,668 | 115,864,226 | 1,092,607 | 6,347,904 |
| Užpelkiai | 169,299 | 1.74 | 293,655 | 234,924 | 14,683 | 53,837 | 3,406,401 | 126,859 | 3,081,647 | 40,632 | 157,264 |
| Vadakstis | 580,904 | 1.00 | 580,346 | 464,277 | 29,017 | 106,398 | 6,732,015 | 250,710 | 6,090,208 | 139,417 | 251,681 |
| Total | 38,535,842 | 1.81 | 77,479,906 | 61,983,925 | 3,873,995 | 14,204,779 | 898,766,915 | 33,471,320 | 813,081,530 | 9,248,602 | 42,965,463 |
Source: own work.
This study highlights the scale of ecological and climate-related degradation associated with abandoned peat extraction sites in Lithuania. Despite the end of mining activities in many of these areas, they remain in a drained state that continues to drive peat loss, carbon emissions, and limited ecosystem function.
Our main findings are:
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Peat loss estimates from extraction at 33 abandoned peatland quarries totaled 77.5 million m3, which equates to a current value of €899 million in revenue. Nonetheless, the abandoned peatland quarries still host peat deposits ranging from 0.5 m to 2 m in average depth. Thus, rewetting is needed.
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The drying and degradation of peatlands also reduced the water storage capacity across the 33 study sites, with an estimated loss of approx. 62 million liters of water, equaling approx. €33 million. This affects local hydrology and increases the vulnerability to drought, fire, flood and natural biodiversity.
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Soil carbon losses from these sites are substantial. We estimate approx. 14.2 t CO2 emissions equaling €813 million were lost from peat extraction alone. These emissions are largely unaccounted for in land-use sector reporting and undermine climate targets.
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The rewetting of the 33 abandoned peatland quarries is estimated to cost approx. €9.2 million. Given these findings, we argue that rewetting and restoring Lithuania’s drained peatlands should be a clear environmental priority. Blocking drainage ditches, raising water tables, and reintroducing peat-forming vegetation would help halt further degradation. Over a long timeframe, these sites could shift from being net carbon sources to functioning wetlands that support biodiversity and store water. This creates an opportunity to align restoration efforts with conservation policies and EU climate goals. Our results support current EU initiatives that call for the restoration of organic soils, particularly under the Nature Restoration Law and rules for the land use, landuse change and forestry (LULUCF) (Regulation (EU) 2018/841).
In conclusion, “drained and forgotten” peatlands are hotspots of avoidable carbon and water service loss. Restoration offers a clear, cost-effective path to reversing this trend. By quantifying peat loss, carbon emissions, and hydrological impacts, this study provides the evidence base needed to support targeted, science-based restoration strategies. We recommend prioritizing the rewetting of these areas within national and EU restoration programs, and monitoring outcomes to track improvements in carbon and water dynamics over time.