Session HS10.3

[Programme]

HS10.3 | Peatland hydrology: From tropical to subarctic latitudes

Peatland hydrology: From tropical to subarctic latitudes

Convener: Alex Cobb | Co-conveners: Emma Shuttleworth, Michel Bechtold, Marie Larocque, Abbey L. MarcotteECSECS

Orals

| Fri, 19 Apr, 08:30–10:15 (CEST)

Room 2.15

Posters on site

| Attendance Thu, 18 Apr, 16:15–18:00 (CEST) | Display Thu, 18 Apr, 14:00–18:00

Hall A

Peatlands develop in specific hydrological settings and are highly sensitive to changes in hydrological conditions and climate. For example, both peat hydrological properties and peatland greenhouse gas balance can change drastically after disturbances such as drainage, permafrost thaw, or mechanical compaction. Hydrological conditions are also a key control for a number of the ecosystem services offered or regulated by peatlands, including biodiversity, carbon storage, and nutrient retention. In addition, the role of pristine and disturbed peatlands in flood retention, support of low flows and regional climate remains debated. As hydrological and biotic processes in peatlands are strongly coupled, predicting the eco-hydrological effects of climate change, degradation, and restoration on peatland ecosystem responses—including greenhouse gas emissions—is a demanding task for the peatland community.

This session addresses peatland hydrology and its interaction with ecosystem processes in all latitudes. We especially encourage papers on permafrost and tropical peatlands for which field studies are scarce and inclusion into Earth system models is largely pending. We invite submissions on: (1) hydrological processes operating in all types of peatlands (pristine, disturbed, degraded, drained, managed, rehabilitated or re-wetted) in boreal, temperate, and tropical latitudes; and (2) the first-order control of peatland hydrology on all kinds of peatland functions.

We aim to advance the transfer of knowledge and methods and welcome laboratory, field, remote sensing, and modeling studies on hydrological, hydrochemical, biogeochemical, ecohydrological or geophysical topics, as well as ecosystem service assessments.

Orals: Fri, 19 Apr | Room 2.15

Chairpersons: Alex Cobb, Abbey L. Marcotte

08:30–08:35

5-minute convener introduction

08:35–08:45

EGU24-22192

solicited

On-site presentation

Hydrology, water chemistry and organic matter in peatland pools and headwater streams

Cat Moody, Joseph Holden, Pippa Chapman, Nicholle Bell, Logan Mackay, and Ezra Kitson

Peatland pools that result from human activities (e.g. disturbance from building roads, or rewetting) have different hydrology to pools that have formed naturally. This impacts on biogeochemical processes within the pool. Studies of peatland pools in the Flow Country (Scotland, UK) showed artificial pools had a smaller surface area than natural pools, but natural pools were shallower and had less variable depth than artificial pools. During storm events, the artificial pools had a significantly larger response to rainfall input. The site with artificial peat pools had more variable water table depths within the peat than the site with natural pools. There were also differences in biogeochemistry between the natural and artificial pools: natural pools had lower organic carbon (OC) and dissolved CO₂ concentration than artificial pools, and there was a higher carbon turnover in natural pools.

Similar to peatland pools, small headwater streams are hotspots for OC processing. In a study of 200 small peatland water bodies across the UK (headwaters, streams and pools, with catchment area less than 1 km² and at least 70% peat cover), the mean dissolved OC (DOC) concentration was 24 mg C L^-1 (95% CI: 21-27), but in pools, the mean DOC concentration was higher, 34 mg C L^-1. Dissolved organic matter (DOM) elemental composition was also significantly different from pools, headwaters and small streams.

As a result of these studies, two samples of DOM (one from natural and one from an artificial pool) were analysed using FT-ICR MS. There were 11,424 molecular formulae identified in the two samples. There were 6,167 individual compounds in DOM from the artificial pool, of which 29% were unique to that pool (not found in the natural pool); there were 5,257 compounds in the natural pool DOM, of which 17% were unique to that pool. There were differences in structural indicators (e.g. double bond equivalent) and average size (e.g. m/z) of DOM compounds unique to each pool.

These studies have shown how catchment-scale peatland condition is detectable on the molecular level, causing differences in organic matter structure, which will have implications for carbon turnover, processing and transport, and GHG emissions from peatland water.

How to cite: Moody, C., Holden, J., Chapman, P., Bell, N., Mackay, L., and Kitson, E.: Hydrology, water chemistry and organic matter in peatland pools and headwater streams, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-22192, https://doi.org/10.5194/egusphere-egu24-22192, 2024.

08:45–08:55

EGU24-6071

ECS

On-site presentation

Temporal Dynamics of Dissolved Organic Carbon at the Outlet of a Rewetted Coastal Peatland

Hadi Meidani and Manon Janssen

Peatlands have a major role in the global carbon cycle. While the gaseous export of carbon from peatlands has already been well-recognized, the dissolved organic carbon (DOC) fraction has not been equally noticed. Despite covering a small area (less than 3%), peatlands contribute from 12% to 20% of the DOC being released to oceans. The DOC dynamics in streams draining peatlands are highly variable, both on seasonal and event scales, and the corresponding drivers are still under discussion, particularly differing between disturbed and pristine peatlands. The objective of this study is to determine the DOC dynamics at the outlet of a rewetted coastal peatland and assess the effects of discharge and salinity. The study area is the nature reserve “Heiligensee and Hütelmoor” on the German Baltic Sea coast with an area of 350 ha. Here, high-frequency time series of discharge and DOC concentrations (complemented with regular samplings) are measured at the drainage/ditch system outlet, and consequently, the DOC export is calculated. According to the results, DOC concentrations demonstrate a seasonal trend and seem to be diluted during higher discharges by rainfall. However, they show no evident correlation with salinity. Moreover, the high‑frequency DOC concentrations, although available only for a limited period, indicate high variabilities following rainfall/discharge events. The discharge exhibits seasonal variabilities with an increase throughout winter, and then, a continuous decrease, and is highly responsive to rainfall events. The DOC exports are strongly linked with the discharge and thus show a similar pattern with the highest values in winter and spring. Our results highlight the necessity of high-frequency fluvial DOC monitoring with respect to extreme flow events in rewetted peatlands and a deeper investigation of the hydroclimatological controls through time-series/statistical analyses. This could provide valuable insights into mitigating excessive DOC export from rewetted peatlands.

How to cite: Meidani, H. and Janssen, M.: Temporal Dynamics of Dissolved Organic Carbon at the Outlet of a Rewetted Coastal Peatland, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6071, https://doi.org/10.5194/egusphere-egu24-6071, 2024.

08:55–09:05

EGU24-2388

ECS

Highlight

On-site presentation

Harmful effluents from a degraded peatland catchment following rainstorms

Lipe Renato Dantas Mendes, Catharine Pschenyckyj, Behzad Mozafari, Michael Bruen, Fiachra O'Loughlin, and Florence Renou-Wilson

Peatlands are a large store of carbon and nutrients. In Ireland, these cover 21% of the country’s area and have been extensively drained mainly for peat extraction (both industrial and domestic). This has intensified decomposition and water flow from peat-dominated catchments. Consequently, there has been an increase in the discharge of harmful contaminants downstream that may violate the EU Water Framework Directive requirements for good ecological status of surface waters, and ultimately disturb aquatic ecosystems. Climate variations also affect the water quality by mediating the release of nutrients and modifying flows. Mitigation measures that overcome the resulting regulatory, ecological and climate challenges are warranted. For industrial peat extraction in Ireland, ponds have been excavated at the edge-of-field to provide treatment of outflows. However, little is known about the dynamics of the contaminants, and the efficiency of currently implemented measures.

We hypothesize that the quality of water from degraded peatland catchments is highly dynamic and is harmful to surface waters all year round. Prolonging the hydraulic retention time on site with ponds is not sufficient for good treatment due to high proportion of soluble nutrients and unfavorable biogeochemical conditions. We show this with an experiment at the edge of an Irish degraded raised bog subjected to peat extraction where a drainage network allowed water to flow through ponds at the edge-of-field. A monitoring station was installed at the outlet with an automatic sampler which captured water samples during 14 storm events. Moreover, a one-year grab sampling campaign was conducted at the pond inlet and outlet. The samples were analysed for pH, electrical conductivity, and nutrient and ion concentrations. The station also directly measured water quality parameters and flow, for one and a half years. Both meters were then moved to the pond inlet for another year while a flow was monitored at the pond outlet. The amount of sediment deposited in the pond was estimated by counting the number of filled excavator buckets to clean it and then accounting for sediment moisture.

Nutrients in effluents were mostly in soluble forms and varied greatly between storm events. These were particularly high at low flows suggesting a dilution effect. Large nutrient exports occurred only momentarily during extreme high flows. All water quality parameters varied widely throughout the seasons showing significant differences (p < 0.05). pH, nitrate and total ammonia often exceeded environmental water quality standards. Flow and temperature significantly explained the variability of nearly all water quality parameters, and temperature had a greater effect. These had inverse (generally monotonic) and direct (generally linear) relationships, respectively, with water quality parameters, except that flow was directly and linearly related to turbidity. Therefore, warm periods appear to produce nutrient and ion-rich effluents, whereas cold and rainy periods appear to produce acidic and turbid effluents. The dissolved water quality at the pond outlet was similar to the inlet indicating minimal treatment by the pond. However, it retained around 23 L of sediment per day. The results corroborate our hypotheses highlighting the need for more appropriate mitigation measures.

How to cite: Dantas Mendes, L. R., Pschenyckyj, C., Mozafari, B., Bruen, M., O'Loughlin, F., and Renou-Wilson, F.: Harmful effluents from a degraded peatland catchment following rainstorms, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2388, https://doi.org/10.5194/egusphere-egu24-2388, 2024.

09:05–09:15

EGU24-18147

ECS

On-site presentation

How groundwater abstraction and tree management affect water levels and peat properties in a groundwater fed peatland

(withdrawn)

Elaine Halliday, Anne Verhoef, and Steve Robinson

09:15–09:25

EGU24-11756

ECS

On-site presentation

Integrating Microtopography and Vegetation Influences: A Landscape-Level Approach to Estimating CO2 Emissions in Tropical Peatlands

Rasis Putra Ritonga, Adibtya Asyhari, Jennifer C. Bowen, Gusti Z. Anshari, Adi Gangga, Eko Yuono, and Nisa Novita

Groundwater level (GWL) and soil temperature are critical parameters for estimating CO₂ emissions from tropical peatlands. However, scaling CO₂ emissions to the landscape level remains challenging because of the heterogeneity of canopy coverage on different land use types that influence soil temperature and the irregularity of peat surface microtopography that regulates water accumulation and drainage. This study aims to address this gap by (1) capturing high-frequency measurements of GWL and soil temperature under varying vegetation canopy covers and microtopographic conditions within the same land use type, and (2) using those measurements along with remote sensing approaches to model CO₂ emissions at landscape level. This work was carried out in a secondary swamp forest (SF) and an oil palm (OP) site in Anjongan Dalam Village, Mempawah, West Kalimantan, Indonesia. These sites were selected as they represent the predominant land use types in the country’s peatlands. Solinst Levelogger® 5 were installed along with custom-made multi-depth soil temperature sensors at six locations within each site that accounted for varying canopy covers (sparse and dense) in both land use types. To establish a GHG baseline model, we also conducted biweekly monitoring of soil CO₂ flux using LiCOR LI-7810 Trace Gas Analyzer in both land use types.

In the first-quarter of our measurements (September-December 2023), we made three central observations. Firstly, all twelve plots exhibited similar GWL fluctuation patterns in response to wet and inter-storm (no rain) periods, but the magnitude of these fluctuations varied within measurement points in SF and OP (max. discrepancy = 18.6 and 38.5 cm, respectively). LiDAR observations revealed that microtopography controlled these water levels, suggesting that elevation variations influence the magnitude of GWL. Secondly, a comparison of daytime soil temperatures between sparse and dense canopy cover within each land use type revealed differing magnitudes: sparse vegetation areas, likely due to more open canopies, registered significantly higher near surface soil temperatures for SF (mean = 27.3 and 26.8 °C) and OP (mean = 29.6 and 29.4 °C; p-value < 0.01). Thirdly, our findings imply GWL and soil temperature in SF (R² = 0.66 and 0.32) and OP (R² = 0.61 and 0.65, respectively) significantly influence CO₂ emissions. Taken together, these three observations demonstrate how variations in GWL and soil temperature within the same land use may lead to considerable shifts in the resulting CO₂ emission factors. Still, continued monitoring during the dry season is crucial to further elucidate the impacts of microtopography and vegetation cover on CO₂ emissions. The next phase of our research will be focusing on developing our landscape-level GHG model that will incorporate microtopography and canopy covers. Integrating our distributed ground monitoring data with spatiotemporal remote sensing information will be pivotal in introducing new methodology for improving emission factors for other peatlands following our environmental settings.

How to cite: Ritonga, R. P., Asyhari, A., Bowen, J. C., Anshari, G. Z., Gangga, A., Yuono, E., and Novita, N.: Integrating Microtopography and Vegetation Influences: A Landscape-Level Approach to Estimating CO2 Emissions in Tropical Peatlands, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11756, https://doi.org/10.5194/egusphere-egu24-11756, 2024.

09:25–09:35

EGU24-8124

On-site presentation

Physical parameters of peat and other organic soils can be derived from properties described in the field

Ullrich Dettmann, Bärbel Tiemeyer, Sebastian Heller, Arndt Piayda, Bernd Schemschat, and Stefan Frank

Knowledge about the bulk density and porosity of peat and other organic soils is of major importance, as both parameters directly or indirectly effect hydrological conditions (e.g., soil moisture, water level fluctuation), soil physical processes (e.g., shrinkage, swelling, subsidence) and biological processes (e.g., peat mineralization, peat growth). The agricultural usability (e.g., trafficability, plant growth, yield) and the rewetting and oscillation capacity of peatlands also strongly depend on soil hydraulic properties and, thus, on bulk density and porosity. Additionally, knowledge of bulk density is necessary to convert concentrations (e.g., soil organic carbon content) into volume-related quantities. Bulk density and porosity depend on the botanical origin of the peat, the degree of decomposition and other pedogenetic processes. These soil characteristics can be identified directly during soil examinations in the field. In contrast, the determination of bulk density and porosity requires volume-based sampling and subsequent laboratory analyses.

Here, we present pedotransfer functions for peat and other organic soils to derive bulk density and porosity using random forest models. Based on a dataset from approximately 600 horizons from 100 peatland sites in Germany and other European countries, we built a set of different pedotransfer functions combining predictor variables determined in the field. These included the degree of decomposition, peat type (e.g., Sphagnum peat, Carex peat, amorphous peat), horizon characteristics (e.g., aggregated, oxidized, permanently saturated, ploughed), average horizon depth, rooting intensity (no roots to extremely dense, estimated from root proportion per cm²), admixture of mineral compounds and the occurrence of carbonate (estimated using 10% hydrochloric acid). Further pedotransfer functions were built, using soil organic carbon content as an additional predictor variable.

The results show that bulk density and porosity can be predicted using only a few predictor variables (3-7) with a low bias and high coefficient of determination. Adding soil organic carbon content as an additional predictor variable further improved the pedotransfer functions. Depending on the combination of the predictor variables, root mean square errors (5-fold cross validation) varied between 0.069 to 0.099 g cm^-3 for the bulk density and 3.8 to 4.7% for the porosity pedotransfer functions.

How to cite: Dettmann, U., Tiemeyer, B., Heller, S., Piayda, A., Schemschat, B., and Frank, S.: Physical parameters of peat and other organic soils can be derived from properties described in the field, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8124, https://doi.org/10.5194/egusphere-egu24-8124, 2024.

09:35–09:45

EGU24-2007

ECS

On-site presentation

Modelling post-restoration spatiotemporal changes in peatland water table with optical satellite imagery

Aleksi Isoaho, Lauri Ikkala, Lassi Päkkilä, Hannu Marttila, Santtu Kareksela, and Aleksi Räsänen

Remote sensing (RS) has been suggested as a tool for peatland monitoring. However, there have been only a few studies in which post-restoration hydrological changes have been quantified with RS-based modelling. To address this gap, we developed an approach to assess post-restoration spatiotemporal changes in the peatland water table (WT) with optical Sentinel-2 and Landsat imagery. We tested the approach in eleven northern boreal peatlands (six restored, and five control sites) impacted by forestry drainage in northern Finland using Google Earth Engine cloud computing capabilities. We constructed a random forest regression model with spatiotemporal field-measured WT data as a dependent variable and satellite imagery features as independent variables. To assess the spatiotemporal changes, we constructed representative maps for situations before and after restoration, separately for early summer wet and midsummer dry conditions. To further quantify temporal changes during 2013–2023, and to test statistical significance of restoration, we conducted a bootstrap hypothesis test for the areas near the restoration measures and similar areas in the control sites. The regression model had a relatively good fit and explanatory capacity (R² = 0.61, RMSE = 6.98 cm). The WT maps showed that the post-restoration changes were not uniform and concentrated near the restoration measures. The bootstrap test showed that the WT increased more in the restored areas (5.8–9.4 cm) than in the control areas (0.1–4.5 cm). Our results indicate that restoration impact on surface hydrology can be quantified with optical satellite imagery and a machine learning approach in treeless peatlands.

How to cite: Isoaho, A., Ikkala, L., Päkkilä, L., Marttila, H., Kareksela, S., and Räsänen, A.: Modelling post-restoration spatiotemporal changes in peatland water table with optical satellite imagery, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2007, https://doi.org/10.5194/egusphere-egu24-2007, 2024.

09:45–09:55

EGU24-4331

On-site presentation

Evaluating the thermal effects of peatland restoration using UAV monitoring

Jakub Langhammer, Theodora Lendzioch, and Oleksandr Hordiienko

Mid-latitude montane peatlands have undergone extensive anthropogenic modifications in past decades. Projects aimed at their restoration represent critical ecological interventions, reinstating their hydrological regime, preserving biodiversity, and mitigating the effects of climate change.

This research aims to investigate the effect of mid-latitude montane peatland restoration on the responses in land surface temperature (LST) and wetness using multispectral and thermal UAVs supported by instrumental monitoring. We aimed to test the hypothesis that peatland restoration should have a cooling effect on LST due to increased wetness, enhanced evapotranspiration, and latent heat flux.

Multispectral and thermal UAV monitoring, coupled with in-situ instrumental monitoring, was used to acquire data on spatial, quantitative, and qualitative changes in peatland response to restoration aimed at plugging the drains built in the past decades. In particular, we investigated: (i) the change in total surface water extent after peatland restoration, (ii) the LST response of restoration dikes, and (iii) the distribution of LST in restored peatlands.

The study was conducted in the montane peat bog of Rokytka in the Šumava Mountains, one of Central Europe's largest montane peatland complexes. The monitoring covered the vegetation seasons from 2018 to 2023, a period of extensive restoration activities in the peatland headwaters, allowing assessment of both pre-and post-restoration conditions.

The very high spatial resolution of the spatial data allowed us to analyze changes in peatland area in terms of canopy structure, wetness, and thermal response. The results showed a significant expansion of the waterlogged surface of the peatland due to the clogging of the former drains. However, the land surface temperature analysis indicates that the newly constructed dike systems have only a limited cooling effect compared to the thermal regime of the natural peatland vegetation. Furthermore, the analysis of new and old dike systems showed a continuous decrease of their positive effect.

The study proved that UAV monitoring is a unique monitoring technique that allows obtaining objective information on the thermal effects of peatland restoration, separating their effects from the properties of the surrounding environment, and objectively assessing their impact on the peatland thermal regime.

How to cite: Langhammer, J., Lendzioch, T., and Hordiienko, O.: Evaluating the thermal effects of peatland restoration using UAV monitoring, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4331, https://doi.org/10.5194/egusphere-egu24-4331, 2024.

09:55–10:05

EGU24-3993

ECS

On-site presentation

Integrated hydrological modelling for predicting spatiotemporal variability of water table depths in Danish peatlands

Tanja Denager, Raphael Schneider, Thea Quistgaard, Jesper Riis Christiansen, Peter L. Langen, and Simon Stisen

It is well known that artificially drained peatlands are net greenhouse gas (GHG) sources to the atmosphere. In peatlands, the depth of the groundwater table i.e. the water table depth (WTD), is an important driver of carbon dioxide (CO₂) and methane (CH₄) emissions.

Integrated hydrological models simulating transient unsaturated and saturated subsurface flow in peatlands, allow mapping of the spatiotemporal variability of WTD and thereby the impact on GHG on daily, seasonal, and inter-annual timescales. Thereby, hydrological modelling of peatlands has the potential to assist more accurate estimates of GHG emissions compared to the simple default IPCC emission factors and/or long-term average WTD estimates used in prevalent national GHG inventories.

Here we apply physically-based 3D modelling of the WTD to a highly monitored peatland, as a case-study representing common drained and degraded peatland soils in Denmark. The catchment scale model is based on an advancement of the National Hydrological Model of Denmark running in the numerical simulation tool MIKE-SHE/MIKE-Hydro.

We identify the main processes governing peatland WTD dynamics in the model and develop a novel parameter calibration scheme focusing on WTD dynamics. We use objective functions tailored to timeseries of WTD by combining individual components of a modified version of the Kling-Gupta Efficient (KGE) with low- and highpass filters to separate the WTD signal into seasonal patterns and short-term precipitation responses. Using the Pareto Archived Dynamically Dimensioned Search (PADDS) algorithm to obtain the pareto front enables post-weighting of objective functions for optimal tradeoff analysis. The model is calibrated at 100m scale and a forward run with the optimal parameter values demonstrate mapping of WTD dynamics and statistics for potential use in GHG inventories at 20m scale.

Those achievements will lead to more robust representation of peatland hydrology in hydrological models and will facilitate analysis of hotspots and hot moments in GHG emissions and enable scenario-based analysis of climate change and management impacts on WTD dynamics in peatlands. This will support the Danish rewetting strategies and better upscaling of GHG emissions for the national inventories.

How to cite: Denager, T., Schneider, R., Quistgaard, T., Riis Christiansen, J., L. Langen, P., and Stisen, S.: Integrated hydrological modelling for predicting spatiotemporal variability of water table depths in Danish peatlands, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-3993, https://doi.org/10.5194/egusphere-egu24-3993, 2024.

10:05–10:15

EGU24-16791

On-site presentation

Lessons learned from Hydrological Modelling of Northern Temperate Peatlands

Fiachra O'Loughlin, Behzad Mozafari, Michael Bruen, Shane Donohue, and Florence Renou-Wilson

Hydrological modelling of peatlands requires capturing the complex interactions between overland and subsurface processes along with any anthropogenic impacts, such as artificial drainage for peat extraction and agriculture. To date there has been limited intercomparison studies evaluating the hydrological performance of multiple rainfall-runoff models.

Here, we present the results of two different modelling comparison studies for three raised peatlands located in Ireland. These peatlands have all being heavily impacted by artificial drainage for peat extraction; however, peat extraction activities have halted, and one has been rewetted. The first study compares 47 conceptual rainfall-runoff models included in the MARRMoT toolbox at all three sites, while the second study uses a more process-based framework, SUMMA, to represent the different processes at a drained site with various model configurations.

Results from the first study show that there is a significant drop in the ability to simulate the rewetted peatland compared to the drained peatland sites. This study also indicate that the while no single model can outperform others, multi-model ensemble approaches offer better performances. The results from the SUMMA framework highlight the importance of representing the artificial drainage component in simulating the hydrology of drained peatlands. Performance increased significantly once we coded this component into the SUMMA framework.

How to cite: O'Loughlin, F., Mozafari, B., Bruen, M., Donohue, S., and Renou-Wilson, F.: Lessons learned from Hydrological Modelling of Northern Temperate Peatlands, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16791, https://doi.org/10.5194/egusphere-egu24-16791, 2024.

Posters on site: Thu, 18 Apr, 16:15–18:00 | Hall A

Display time: Thu, 18 Apr 14:00–Thu, 18 Apr 18:00

Chairpersons: Emma Shuttleworth, Alex Cobb

A.89

EGU24-562

ECS

Highlight

After the flames: Post-wildfire heavy metal mobilisation in a contaminated temperate peatland

Abbey L. Marcotte, Juul Limpens, Emma L. Shuttleworth, Gareth Clay, João Pedro Nunes, Cristina Santín, Stefan H. Doer, Jonay Neris, Jeff Warburton, Richard C. Chiverrell, and Nicholas Kettridge

Intact peatlands are key resources for freshwater that contribute to multiple hydrological ecosystem services. They retain rainwater and regulate water quality downstream by storing contaminants in the peat profile. The release of heavy metals and nutrients, through burning or erosion of near-surface deposits, has the potential to provide a persistent source of legacy contamination, namely metal contamination, to downstream drinking water supplies. With future climate change increasing the frequency and severity of wildfires in summer and heavy rainfall in winter, the risk of contaminant release from high-latitude peat regions and downstream impact is uncertain.

In June 2018, a major wildfire affected an area of upland moorland (Saddleworth Moor, UK), which contains peat deposits contaminated with atmospherically derived metal deposits. We assessed potential water quality impacts from hillslope contaminant source to the fluvial system by monitoring of heavy metals in the catchment, namely lead (Pb), zinc (Zn), copper (Cu) and nickel (Ni). Specifically, we quantified the (1) metal concentrations in ash deposits resulting from contrasting burn severities; (2) dissolution and erosion of ash and peat deposits under intense rainstorm events; and (3) their transport via the stream network to the receiving reservoir. Ash and peat samples obtained following the wildfire were analysed for total elemental concentration and leaching potential. We calculated ash loads at different burn severities and hillslope erosion was monitored through a series of sediment fences. Heavy metal concentrations in five rainstorm runoff events were measured at the stream outlet of a small catchment within the burn perimeter in the year following the wildfire.

Both ash and peat samples had elevated total heavy metal concentrations, which varied spatially across the study site. The spatial variability was partly associated with different burn severities and ash loads. In extreme burn severity areas, ash loads reached nearly 40 t ha^-1 and Pb concentrations in ash, for example, were as high as 2650 µg g^-1, indicating particularly high potential for contamination of water sources. Conversely, the maximum concentration of dissolved heavy metals in the stream-flow were much lower during the initial post-wildfire storm events (Pb 0.77 µg g^-1; Zn 38.67 µg g^-1; Cu 5.05 µg g^-1; Ni 0.26 µg g^-1).

The low solubility of heavy metals in both ash and peat samples likely constrains mobilisation by dissolution during storm events, suggesting low acute risk to drinking water quality post-wildfire. Instead, we hypothesise that metals likely remain bound to peat and ash particles, and are subsequently transported downstream in particulate form. Further quantification of heavy metals in sediment cores from sink zones will test if the metal contaminants pose a future chronic threat to drinking water quality.

How to cite: Marcotte, A. L., Limpens, J., Shuttleworth, E. L., Clay, G., Nunes, J. P., Santín, C., Doer, S. H., Neris, J., Warburton, J., Chiverrell, R. C., and Kettridge, N.: After the flames: Post-wildfire heavy metal mobilisation in a contaminated temperate peatland, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-562, https://doi.org/10.5194/egusphere-egu24-562, 2024.

A.90

EGU24-12338

ECS

Dissolved Nutrients in Natural and Rewetted Peatlands: A Comparative Analysis

Nimisha Krishnankutty, Bo Iversen, Goswin Heckrath, Hans Christian Hansen, and Dominik Zak

Intensive agriculture and artificial drainage have transformed natural peatlands into significant sources of greenhouse gas emissions as well as phosphorus and nitrogen pollution, the latter leading to an increased risk of eutrophication of adjacent water bodies. To address this issue and comply with the EU Water Framework Directive, restoring peatlands is a key strategy involving widespread rewetting to re-establish their roles as nutrient and carbon sinks. To achieve restoration objectives, it is essential to analyse and understand the temporal and spatial variability in porewater composition within natural and rewetted peatlands, with a specific focus on the influence of peatland type (bog or fen) and peat degradation status. Hence, an extensive international field survey of soil water and bulk soil was conducted from 1997 to 2017 on 60 natural and rewetted peatlands (both bogs and fens) in Germany, Poland, Estonia, Sweden, and the United Kingdom. The anoxic porewater samples were collected from water-saturated soil layers between 0 and 0.6 m depth. To quantify the concentrations of various chemical compounds in porewater at each location, at least three samples were taken using dialysis samplers within a spatial range of 5 to 10 meters. Selected sites were monitored for seasonal changes over a post-wetting period of 10 to 20 years. The results show significant differences in peat characteristics of upper soil layers from rewetted peatlands and natural peatlands, with the lowest values for nutrient contents, particularly in bogs. Notably, rewetted peatlands did not consistently display higher pore water concentrations of dissolved compounds compared to natural peatlands. However, in heavily drained and rewetted fens, anoxic pore waters exhibited concentrations of soluble reactive phosphorus (SRP), ammonium, and dissolved organic carbon one to two orders of magnitude higher than those in their natural counterparts. For example, SRP concentration in highly degraded peatlands ranged from 0.54 mg/L to 18.9 mg/L compared to 0.01 mg/L to and 3.6 mg/L in the natural peatlands. Weakly drained peatlands had, in some cases, slightly higher concentrations of dissolved substances compared to natural peatlands, but the differences were not statistically significant. Therefore, the research highlights the importance of porewater composition concerning the type of peatland, its degradation status, and spatial-temporal fluctuations in restored peatlands.

How to cite: Krishnankutty, N., Iversen, B., Heckrath, G., Hansen, H. C., and Zak, D.: Dissolved Nutrients in Natural and Rewetted Peatlands: A Comparative Analysis, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12338, https://doi.org/10.5194/egusphere-egu24-12338, 2024.

A.91

EGU24-13481

Impact of changing groundwater flow paths on CO2 and CH4 dynamics in the groundwater of temperate-to-arctic mires

Anna Sieczko, Hanna Silvennoinen, Anders Lyngstad, Marta Stachowicz, Paweł Osuch, Robert Michałowski, Paweł Trandziuk, and Mateusz Grygoruk

Mires are one of the systems, which are highly affected by climate change. At the same time, they are main sources of greenhouse gases (GHG) such as methane (CH₄) and carbon dioxide (CO₂). Considering that hydrological patterns remain major factors affecting these emissions and they are likely to be affected by climate change, GHG fluxes may be altered as well. Whereas majority of the studies focused on direct GHG emissions from the peat or mire surface waters, less in known about the processes of groundwater flow especially in relation to transfer of GHG-rich groundwater to the mire ecosystems.

The main objective of this study was to assess how dynamics of CO₂ and CH₄ in groundwater of mires is likely to be affected due to changed paths of groundwater flow.

The study was conducted from May 2023 till October 2023 in four mires located along latitudinal gradient from subarctic Norway to temperate areas in Poland, which serve as examples of systems exposed to abrupt climate change. They include Nordic permafrost and bog-like systems in Norway through bog-lake system in Poland. The study used the set of gas piezometers (gas-equilibrators) located towards-to-lake transect, where concentrations of CO₂ and CH₄ were measured in vertical profiles (2 m, 1m, 0.1m). Simultaneously, water levels were measured with automatic pressure transducers in a 3-h interval. We also documented electric conductivity of groundwater along the transects in which the dynamics of CO₂ and CH₄ were assessed.

We determined the amounts of CO₂ and CH₄ transported by groundwater to the mires. Our results demonstrate high vertical and temporal variability of GHG concentrations in groundwater of mires, which has implications for determination of future carbon balance in such areas. Additionally, our findings imply that groundwater is an important GHG source to the mire and need to be considered in the light of climate change as increasing sources of GHG into the atmosphere. Changes in groundwater flow caused by global warming (e.g., palsa mires decomposition, increase of evapotranspiration in temperate mires) can have significant influence on emissions of GHG in the future.

How to cite: Sieczko, A., Silvennoinen, H., Lyngstad, A., Stachowicz, M., Osuch, P., Michałowski, R., Trandziuk, P., and Grygoruk, M.: Impact of changing groundwater flow paths on CO2 and CH4 dynamics in the groundwater of temperate-to-arctic mires, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13481, https://doi.org/10.5194/egusphere-egu24-13481, 2024.

A.92

EGU24-21369

Highlight

Climate and hydrology control apparent rates of peat accumulation across Europe

Graeme T. Swindles, Donal J. Mullan, Neil T. Brannigan, Thomas G. Sim, Angela Gallego-Sala, Maarten Blaauw, Mariusz Lamentowicz Lamentowicz, Sophie M. Green, Thomas P. Roland, and Richard Fewster and the European peatland research group

Peat accumulates when there is a positive mass balance between plant productivity inputs and litter/peat decomposition losses. Here we examine apparent peat accumulation rates (aPAR) during the last two millennia from 28 well-dated European peatlands and find them to range between 0.005 and 0.448 cm yr^-1 (mean = 0.118 cm yr^-1). Our work provides important context for the commonplace assertion that peatlands accumulate at ~1mm per year. We find that relationships between aPAR and climatic variables are generally weak – summer temperature is the only significant climatic control on aPAR across our European sites. aPAR tends to be higher when water-table depth (reconstructed from testate-amoeba subfossils) is within 5-10 cm of the peatland surface. When a Generalized Additive Model and Gaussian Response Curve are fitted to the data, both methods show that the optimal water-table depth for highest aPAR is ~10 cm. aPAR is generally lower when water table depths are <0 cm (standing water) or >25 cm, which may relate to a decrease in plant productivity and increased decomposition losses, respectively. These findings corroborate contemporary experimental studies which examined the relationship between peatland water-table depth, or the thickness of the aerobic surface layer (the ‘acrotelm’), and the rate of peat formation. Our work suggests that for European peat bogs, an average water-table depth of ~10 cm is optimal to enable rapid peat growth and therefore carbon sequestration in the long term. This has important implications for peatland restoration and rewetting strategies, in our global efforts to mitigate climate change.

How to cite: Swindles, G. T., Mullan, D. J., Brannigan, N. T., Sim, T. G., Gallego-Sala, A., Blaauw, M., Lamentowicz, M. L., Green, S. M., Roland, T. P., and Fewster, R. and the European peatland research group: Climate and hydrology control apparent rates of peat accumulation across Europe, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-21369, https://doi.org/10.5194/egusphere-egu24-21369, 2024.

A.93

EGU24-13729

ECS

Modeling the Influence of Subsurface Geology on Northern Peatland Hydrology

Victoria Niedzinski, Andrew Reeve, Lee Slater, and Xavier Comas

Peatlands are complex wetlands that play an important role in global carbon cycling as both carbon sinks and sources. They contain over one-third of all global soil carbon but cover <3% of all land surfaces. The hydrology of a peatland exerts a significant control on overall carbon cycling as the position of the water table directly impacts carbon sequestration and emission while circulation within the peat basin will influence nutrient availability. Hydro-geophysical studies of northern peatlands over the last two decades have identified the presence of eskers buried beneath some peat deposits in Maine. These studies have hypothesized that eskers drive vertical groundwater flow within these systems and may act as hotspots for methane emissions. However, only conceptual hydrologic models have been developed to support this claim. Using the results of these studies along with new hydrologic and geophysical datasets, a USGS MODFLOW 6, finite-difference groundwater flow model was developed for Caribou Bog near Bangor, ME. Caribou Bog is a multi-unit, ombrotrophic, domed bog with a patterned pool system. Groundwater flow simulations were run at regional and local scales by inserting a fine-scale model encompassing a single peat unit into a coarser-grid, watershed area. The PEST parameter estimation package was used to calibrate the model and MODPATH 7 was used to identify flow paths within the model. Simulation results show that these esker deposits enhance vertical flow through the peat and potentially connect the peatland to the regional aquifer system. These results challenge the traditional viewpoint that ombrotrophic peat systems in boreal regions are relatively disconnected from groundwater flow. Furthermore, they may provide insights into the spatial variability of carbon cycling within peatlands, particularly to assess hydrologic response caused by changing precipitation patterns and warming temperatures expected due to climate change.

How to cite: Niedzinski, V., Reeve, A., Slater, L., and Comas, X.: Modeling the Influence of Subsurface Geology on Northern Peatland Hydrology, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13729, https://doi.org/10.5194/egusphere-egu24-13729, 2024.

Discussion Post a comment

A.94

EGU24-4553

ECS

The Effect of Underground Pipe Drainage and Consequent Site Restoration by Drainage Inactivation on the Ability of Soils to Retain Water.

Jimmy Clifford Oppong, Jana Macháčková, and Jan Frouz

Drainage is often used to increase agriculture production, but it has adverse effects on biodiversity and water retention. Here, the effect of
subsurface pipe drainage on peat meadows near Senotín (Czechia), which were drained from the mid-1980s to 1990s, was studied. Attempts
were made to restore the peat meadows by damming drainage pipes using clay-filled trenches in 1996. In this case study, the effect on the
depth of the water table, soil water retention, infiltration, and soil temperature were recorded. Measurements of the original peat meadow
(undrained site), drained meadow (drained site), and restored meadow (restored site) before restoration and two decades after restoration
were recorded. The water table in undrained areas was higher than at drained and restored sites, indicating that drainage had a lasting effect
on drained and restored sites. Infiltration was lowest at the undrained site, greater at the drained site, and highest at the restored sites. Field
water capacity was lowest at the restored site, greater at the drained site, and highest at the undrained site. Soil water content at maximum
saturation was lowest at the restored site, greater at the drained site, and highest at the undrained site. Soil temperature was highest at the
restored site with no significant difference between the undrained and drained sites. Soil moisture levels were highest at the undrained site
and lowest at the drained site. In addition, the undrained and restored sites did not differ significantly in soil moisture content. In conclusion,
restoration did not have a significant effect on the level of the water table, initiation of peat formation, or ability of soil to hold water.

How to cite: Oppong, J. C., Macháčková, J., and Frouz, J.: The Effect of Underground Pipe Drainage and Consequent Site Restoration by Drainage Inactivation on the Ability of Soils to Retain Water., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4553, https://doi.org/10.5194/egusphere-egu24-4553, 2024.

A.95

EGU24-5066

ECS

Soil Shrinkage Characteristics of Peat and Other Organic Soils

Ronny Seidel, Ullrich Dettmann, and Bärbel Tiemeyer

Shrinkage is the volume reduction of a soil due to desiccation and decreasing pore pressure. This is important for the determination of volume based physical and hydraulic soil properties in the laboratory e.g., bulk density, volumetric moisture and water retention functions. Furthermore, it leads to changing surface elevation and crack formation at the field scale.

There are two types of shrinking soils, clayey soils and organic soils, which are defined here as soils having a soil organic carbon content (SOC) above 7.5%. Clayey and organic soils differ strongly in their shrinkage behavior. Furthermore, only few shrinkage studies differentiate between different organic soils. Parameters of existing shrinkage models are fully empiric and not directly linked to soil properties as dry bulk density, SOC, botanical composition and degree of decomposition.

To determine the soil shrinkage characteristics (SSC i.e., relationship between moisture ratio and void ratio) of a variety of organic soils, we determined sample volumes with a three-dimensional (3D) structured light scanner at different moisture states from full saturation to dryness. We sampled 33 horizons (n = 4 replicates each) covering a wide range of botanical composition, development stages and degree of decompositions. Desiccation was performed by suction plates up to pressure heads of -200 hPa, followed by evaporation and oven-drying at 105°C. Volume and height of the 3D models created this way were determined by 3D graphic software and R, respectively. The volumetric moisture was determined by weighing the sample before and after scanning. Afterwards, volume and volumetric moisture were converted to moisture ratio and void ratio with the volume of solid particles. Due to small differences in particle volume between the replicates, both, moisture and void ratio were normalized by dividing them by the value at saturation. This normalization led to congruent results for the replicates.

The shape of the SSCs strongly depended on the botanical composition and degree of decomposition. Peat consisting of slightly decomposed Sphagnum remains showed a supernormal shrinkage phase, i.e., volume reduction exceeds lost water volume at the dry end of the SSC and a relatively large range where volume reduction is (much) smaller than lost water volume, i.e., subnormal or structural shrinkage phase, at the wet end. The latter behavior was also shown by amorphous top soils. With increasing degree of decomposition or complete absence of Sphagnum remains the SSC flattened and tended to show a (near-) normal shrinkage phase, i.e., volume reduction equals lost water volume.

The results showed that rigid Sphagnum remains strongly influence the shrinkage behavior of organic soils by stabilizing the matrix during desiccation until the large pores collapse rapidly when soil moisture and tension undercut a certain level. The SSC of organic soils without rigid fibers were more similar to SSCs of clayey soils.

How to cite: Seidel, R., Dettmann, U., and Tiemeyer, B.: Soil Shrinkage Characteristics of Peat and Other Organic Soils , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5066, https://doi.org/10.5194/egusphere-egu24-5066, 2024.

A.96

EGU24-5026

ECS

Drop penetration dynamics of rhamnolipid biosurfactant on peat

ReddyPrasanna Duggireddy and Gilboa Arye

Peat and peat-based growing media continue to serve as the major constituents in soil-less cultivation due to their favorable physical and hydraulic characteristics. However, the substrate’s inherent high organic nature, and the intensive dehydration process employed to compact peat into bales for cost effective transportation , results in the substrate development of water repellency. Consequently, this alters the media's optimal physical and hydraulic characteristics and reducing productivity in cultivation systems. Efforts to ameliorate substrate water repellency have predominantly involved the application of wetting agents, primarily focusing on their effect on various plant growth parameters. Synthetic surfactants were proposed to treat the substrate’s water repellency, but given the environmental concerns, alternative strategies become imperative. Biosurfactants, particularly rhamnolipids, have emerged as intriguing compounds at the scientific and commercial levels. Nonetheless, comprehensive quantitative investigations on the rate and extent of wetting and spreading behaviors of aqueous biosurfactant solutions which is essential for understanding drop penetration dynamics on peat, are currently inadequate. In this regard, the main objective of this study is to quantify the drop penetration dynamics of biosurfactants on peat porous substrate under different initial moisture conditions and on peat pellet compressed at different pressures to account for different densities and surface roughness. The study involved measurements of contact angle (CA), drop height, base diameter, and volume of aqueous biosurfactant solutions on prewetted peat with water and biosurfactant and peat pellets using optical tensiometer (OCA-15, Data Physics, Germany). The results demonstrate the relative degree of water repellency with the droplet dynamics of water exhibiting a CA of ~120⁰ and relatively constant drop height and base diameter. Conversely, biosurfactant droplets reduced drop height and volume, and the CA of 120⁰-80⁰ was dependent on prewetting conditions. Furthermore, drop penetration dynamics into pellet peat highlighted the role of surface roughness with higher CA at lower compression pressure (69 bars) relative to higher one (517 bars). Furthermore, the study revealed a pronounced dependence on biosurfactant solution surface tension (ϒ_lv), with negligible CA changes within the higher ϒ_lv ( from 72 down to 41mN/m) domain and significant alterations within the lower ϒ_lv (down to 33 mN/m) domain. These outcomes underscore the effectiveness of rhamnolipid biosurfactant in aiding drop infiltration into initially hydrophobic peat, implying its role in aiding to peat wettability.

Keywords: Peat, Pellets, water repellency, contact angle, surface tension, rhamnolipid biosurfactant, droplet dynamics.

How to cite: Duggireddy, R. and Arye, G.: Drop penetration dynamics of rhamnolipid biosurfactant on peat, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5026, https://doi.org/10.5194/egusphere-egu24-5026, 2024.

A.97

EGU24-7097

ECS

Hydrological dynamics of a Northern cultivated peatland and implications for management

Tung Pham, Hannu Marttila, Maarit Liimatainen, Timo Lötjönen, Jarkko Kekkonen, Miika Läpikivi, and Bjørn Kløve

Cultivated peatlands play a significant role in grass and dairy production, particularly in Northern regions. However, agricultural activities on these organic soils often lead to undesirable environmental effects, namely increased nutrient leaching and greenhouse gas (GHG) emissions. The hydrological characteristics and dynamics of cultivated peatlands significantly influence the formation of leachable nutrients and GHGs. Currently, there is a gap in the comprehensive understanding of hydrological responses in these cultivated areas. To address this gap, the NorPeat research platform at Ruukki research station, managed by the Natural Resources Institute Finland (Luke), has been established in Northern Ostrobothnia, Finland. The site features varying peat thickness (10-80 cm) over a mineral subsoil and a subsurface drainage system consisting of perforated pipes installed within the mineral layer at a depth of 120-130 cm from the surface. Continuous hydrological monitoring of key parameters such as groundwater table, soil moisture, drainage discharge, precipitation, and soil temperature has been ongoing on the platform since 2016. In this study, we focus on the dynamics of the groundwater table and soil moisture in response to seasonal variations, soil structure, and land management; to establish a comprehensive water balance quantifying water fluxes (evapotranspiration, drain flow, overland flow) to the adjacent stream; and to develop a hydrological conceptual model of the field. The outcomes of this research are expected to improve our understanding of cultivated peatland hydrology, inform future studies on environmental impacts, and provide valuable data for both farmers and policymakers.

How to cite: Pham, T., Marttila, H., Liimatainen, M., Lötjönen, T., Kekkonen, J., Läpikivi, M., and Kløve, B.: Hydrological dynamics of a Northern cultivated peatland and implications for management, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7097, https://doi.org/10.5194/egusphere-egu24-7097, 2024.

A.98

EGU24-4250

ECS

Hydrology in differently drained agricultural peatlands in Norway

Miyuru Gunathilake, Mounir Takiriti, Hannu Marttilla, Synnøve Rivedal, and Bjørn Kløve

High water content and poor trafficability are typical challenges of cultivation on peatlands. Draining of peatlands is necessary for cultivation which results in peat degradation and emission of Green House Gases (GHGs). The primary aim of this ongoing study is to understand the hydrology of “peat inversion” used as an alternative to other drainage systems in Norway. In the peat inversion method, the mineral soil layer underlying the peat soil is excavated and placed on top of the peat to provide a cover layer to limit further decomposition of peat and GHG emissions. To better understand drainage effects on hydrology, Carbon balances and GHG emissions in agricultural peatlands in Norway, we study different drainage systems located in different climatic settings. Water table behavior and the relationship with precipitation is investigated at four cultivated peatland sites: Farstad (Western Norway, wet, mild climates), Våler (Southeast Norway, dry, cold winter dominated), Sortland (Northwest Norway, mild climate), Pasvik (Northern Norway, dry, cold winter dominated). Different drainage settings including pipe drainage, surface grading and peat inversion exist in these fields.

How to cite: Gunathilake, M., Takiriti, M., Marttilla, H., Rivedal, S., and Kløve, B.: Hydrology in differently drained agricultural peatlands in Norway , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4250, https://doi.org/10.5194/egusphere-egu24-4250, 2024.

A.99

EGU24-15862

ECS

Can peatland restoration enhance drought and flood resilience in boreal forests?

Sara Camiolo, Claudia Teutschbein, Gustaf Granath, and Thomas Grabs

Peatlands, unique wetlands where peat forms because waterlogging inhibits decomposing organisms, are predominantly found in the boreal region. In Sweden, nearly 18% of the land surface is covered by forested peatlands. However, many of these areas have experienced severe anthropogenic disturbances in the 20^th century. Drainage, a common practice to improve soil conditions for agriculture and forestry, along with commercial peat harvesting, has exerted considerable pressure on these ecosystems. In recent years, peatlands have been recognized for their value in climate-change mitigation, serving as crucial ecosystems that can store carbon and water. Peatland restoration, often referred to as rewetting, is considered an effective nature-based solution to reinstate hydrological, ecological, and biogeochemical conditions essential for various ecosystem services. Global and national policies actively promote peatland restoration, positioning it as a highly effective measure to build resilience against climate-change impacts. Following a series of extreme summers in Sweden, especially the mitigation of hydroclimatic extreme events, such as floods and droughts, is a widely claimed benefit. However, assessing the success of restoration efforts is difficult due to diverse hydroclimatic conditions, a wide range of catchment properties, long response times to restoration measures, and a limited number of long-term monitored restoration case studies. Specifically, restoration impacts on hydrological functioning, including water storage, flood control, groundwater recharge, and drought buffering, remain poorly understood. To strengthen the scientific basis and provide comprehensive insights for decision-makers, we conducted a literature review synthesizing existing empirical evidence on how rewetting boreal peatlands influences hydrological feedbacks. Our focus was particularly on the role of peatlands during drought and flood events, how their location and the time elapsed after restoration affects drought and flood vulnerability, and how peatlands themselves might be impacted by such extreme events. Our results represent a crucial initial step towards understanding the hydrological mechanisms regulating peatlands over time and under various hydroclimatic conditions, which is pivotal in guiding future conservation, rewetting and sustainable use of peatlands as nature-based solutions.

How to cite: Camiolo, S., Teutschbein, C., Granath, G., and Grabs, T.: Can peatland restoration enhance drought and flood resilience in boreal forests?, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15862, https://doi.org/10.5194/egusphere-egu24-15862, 2024.

Discussion Post a comment

A.100

EGU24-11745

ECS

High-Resolution Monitoring of Eco-hydrological Changes Following Rewetting of European Peatlands – Bridging Earth Observation and Restoration Practices

Laura Giese, Marvin Renken, Marvin Ludwig, Anna Bartel, Jan Lehmann, Klaus-Holger Knorr, and Hanna Meyer

In Europe, approximately 52 % of former peatland area is strongly degraded due to human exploitation. This makes the EU the worlds’ second largest emitter of greenhouse gases from drained peatlands. Rewetting of drained peatland sites has therefore a great climate change mitigation potential, as net greenhouse gas emissions can be strongly reduced in the long term. To assess the success of rewetting actions, there is a strong demand for cost-effective and unified monitoring techniques. With the aid of cloud-based remote sensing, the field of earth observation has quickly improved in terms of data accessability and handling, which facilitates the development of individual open-access solutions for environmental monitoring, and may therefore provide suitable tools to monitor peatland rewetting.

We developed a tool to assess the status and changes of peatlands in terms of vegetation and moisture conditions. Therefore, time-series of vegetation and moisture indices (such as NDVI, NDWI) based on freely available satellite data (such as Landsat) were compiled, which provide spatially and temporally continuous information on changes in peatland ecosystems for the last decades.
Anomalies were calculated with reference to the known pre-rewetting time period of selected peatlands, and pre- and post-rewetting trends were analyzed. This provides a spatio-temporal overview of eco-hydrologic changes at individual user-defined peatland sites, which allows deriving information even for remote locations and inaccessable or protected areas. In this contribution we exemplary focus on a rewetted peatland in Northwestern Germany (Neustaedter Moor) for which we could show a clear signal in NDWI anomalies following a rewetting measure in 2013, indicating that these measures have indeed been effective.

We intend to test the application further at multiple sites in cooperation with practitioners and to assess the analysis by comparing results to field-specific data. The fully automatized multi-index approach is provided as a web-based application, which can be used to summarize and compare the advances in peatland restoration at continental scale also in the future. We aim to provide opportunities for new insights by creating synergies between earth observation and restoration practice in European Peatlands.

This research was funded through the 2020-2021 Biodiversa+ and Water JPI joint call for research projects, under the BiodivRestore ERA-NET Cofund (GA N°101003777), with the EU and the funding organisations DFG (Germany), FWF (Austria), NSC (Poland) and the LNV (The Netherlands)

How to cite: Giese, L., Renken, M., Ludwig, M., Bartel, A., Lehmann, J., Knorr, K.-H., and Meyer, H.: High-Resolution Monitoring of Eco-hydrological Changes Following Rewetting of European Peatlands – Bridging Earth Observation and Restoration Practices, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11745, https://doi.org/10.5194/egusphere-egu24-11745, 2024.