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Widespread drying of European peatlands in recent centuries

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Climate warming and human impacts are thought to be causing peatlands to dry, potentially converting them from sinks to sources of carbon. However, it is unclear whether the hydrological status of peatlands has moved beyond their natural envelope. Here we show that European peatlands have undergone substantial, widespread drying during the last ~300 years. We analyse testate amoeba-derived hydrological reconstructions from 31 peatlands across Britain, Ireland, Scandinavia and Continental Europe to examine changes in peatland surface wetness during the last 2,000 years. We find that 60% of our study sites were drier during the period 1800–2000 ce than they have been for the last 600 years, 40% of sites were drier than they have been for 1,000 years and 24% of sites were drier than they have been for 2,000 years. This marked recent transition in the hydrology of European peatlands is concurrent with compound pressures including climatic drying, warming and direct human impacts on peatlands, although these factors vary among regions and individual sites. Our results suggest that the wetness of many European peatlands may now be moving away from natural baselines. Our findings highlight the need for effective management and restoration of European peatlands.
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https://doi.org/10.1038/s41561-019-0462-z
1School of Geography, University of Leeds, Leeds, UK. 2School of Natural and Built Environment, Queen’s University Belfast, Belfast, UK. 3Ottawa-Carleton
Geoscience Centre and Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada. 4Department of Environment and Geography,
University of York, York, UK. 5Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK. 6Environmental Change Research
Unit, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland. 7Laboratory of Wetland Ecology and Monitoring,
Faculty of Geographical and Geological Sciences, Adam Mickiewicz University, Poznań, Poland. 8School of Science and the Environment, Manchester
Metropolitan University, Manchester, UK. 9Centre for Environmental Change and Quaternary Research, School of Natural and Social Sciences, University
of Gloucestershire, Cheltenham, UK. 10Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main,
Germany. 11Department of Geology, Babeş-Bolyai University, Cluj-Napoca, Romania. 12Aarhus Institute of Advanced Studies, Aarhus University, Aarhus,
Denmark. 13Geological Survey of Canada/Commission géologique du Canada, Calgary, Alberta, Canada. 14Department of Geobotany and Plant Ecology,
Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland. 15Institute of Ecology and Earth Sciences, University of Tartu, Tartu,
Estonia. 16School of Geography and Environmental Science, University of Southampton, Southampton, UK. 17School of Geosciences, The University
of Aberdeen, Aberdeen, UK. 18Department of General Ecology and Hydrobiology, Lomonosov Moscow State University, Moscow, Russia. 19Manaaki
Whenua–Landcare Research, Lincoln, New Zealand. 20Laboratory of Soil Biodiversity, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
21Jardin Botanique de Neuchâtel, Neuchâtel, Switzerland. 22Department of Physical Geography and Landscape Science, Lomonosov Moscow State
University, Moscow, Russia. 23Institute of Geography, Russian Academy of Science, Moscow, Russia. 24Geological Survey of Sweden, Uppsala, Sweden.
25Vaida Elementary School, Vaida, Estonia. 26Department of Zoology and Ecology, Penza State University, Penza, Russia. 27BIAX Consult, Zaandam, the
Netherlands. 28Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario, Canada. *e-mail: g.t.swindles@leeds.ac.uk
Peatlands have acted as globally important carbon (C) sinks
since the Last Glacial Maximum1,2 and contain ~20% of the soil
C pool, despite only covering ~3% of the global landmass3,4.
Peatlands accumulate C when the production of plant litter exceeds
losses from microbial decomposition5. The maintenance of a shallow
water table and near-saturated surface conditions are important for
inhibiting C losses from microbial respiration in peatlands6. Several
factors threaten the persistence of peatland ecosystem services:
climate change, peat extraction, drainage, burning and land-use
modification7. Field manipulations8 and modelling studies9 have
indicated that the deepening of peatland water tables leads to
increasing peat oxidation, in turn causing the peat C stock that has
built up over millennia to be decomposed and released to the atmo-
sphere as carbon dioxide, with likely global-scale implications for cli-
mate change8,10. In Europe, peatlands store approximately five times
more C than forests11 and about half of Europe’s total soil organic C12.
These huge C stores deserve an important place in Europe’s climate
mitigation measures and greenhouse gas emissions policies.
Widespread drying of European peatlands in
recent centuries
Graeme T. Swindles 1,2,3*, Paul J. Morris 1, Donal J. Mullan2, Richard J. Payne4, Thomas P. Roland5,
Matthew J. Amesbury 5,6, Mariusz Lamentowicz 7, T. Edward Turner1, Angela Gallego-Sala 5,
Thomas Sim 1, Iestyn D. Barr 8, Maarten Blaauw 2, Antony Blundell1, Frank M. Chambers9,
Dan J. Charman 5, Angelica Feurdean10,11, Jennifer M. Galloway12,13, Mariusz Gałka14,
Sophie M. Green5, Katarzyna Kajukało7, Edgar Karofeld15, Atte Korhola6, Łukasz Lamentowicz7,
Peter Langdon16, Katarzyna Marcisz7, Dmitri Mauquoy17, Yuri A. Mazei18, Michelle M. McKeown19,
Edward A. D. Mitchell 20,21, Elena Novenko22,23, Gill Plunkett 2, Helen M. Roe2, Kristian Schoning24,
Ülle Sillasoo25, Andrey N. Tsyganov 18,26, Marjolein vander Linden27, Minna Väliranta 6
and Barry Warner28
Climate warming and human impacts are thought to be causing peatlands to dry, potentially converting them from sinks to
sources of carbon. However, it is unclear whether the hydrological status of peatlands has moved beyond their natural envelope.
Here we show that European peatlands have undergone substantial, widespread drying during the last ~300 years. We analyse
testate amoeba-derived hydrological reconstructions from 31 peatlands across Britain, Ireland, Scandinavia and Continental
Europe to examine changes in peatland surface wetness during the last 2,000 years. We find that 60% of our study sites were
drier during the period 1800–2000 
ce
than they have been for the last 600 years, 40% of sites were drier than they have been
for 1,000 years and 24% of sites were drier than they have been for 2,000 years. This marked recent transition in the hydrology
of European peatlands is concurrent with compound pressures including climatic drying, warming and direct human impacts
on peatlands, although these factors vary among regions and individual sites. Our results suggest that the wetness of many
European peatlands may now be moving away from natural baselines. Our findings highlight the need for effective management
and restoration of European peatlands.
NATURE GEOSCIENCE | VOL 12 | NOVEMBER 2019 | 922–928 | www.nature.com/naturegeoscience
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... • Drainage. Drainage is the key driver of the degradation of peat soils (Swindles et al., 2019). In the Nordic countries, between 3 % and 40 % of the original peatland area has been drained for agricultural purposes (Kløve et al., 2017;Szajdak et al., 2020). ...
... • Climate change. Climate-driven drying of European peatlands is likely to have been exacerbated by direct human impacts in recent centuries (Swindles et al., 2019). During a period of significant population growth throughout Europe (McEvedy and Jones, 1978), coupled with the expansion of cropland and intensified land use (Ramankutty and Foley, 1999), hydrological shifts took place. ...
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This report investigates the intricate interplay between the drivers of changes in soil health, along with the pressures and impacts on soil in the 32 European Environment Agency (EEA) member countries, as well as six cooperating countries from the West Balkans, Ukraine, and the UK. It sheds light on the multifaceted challenges facing soil conservation efforts. Our analysis reveals the complex interactions between various factors, both anthropogenic and natural, that shape soil degradation processes and their subsequent consequences. We highlight key findings, including the significant impacts of soil degradation on agriculture, ecosystem resilience, water quality, biodiversity, and human health, underscoring the urgent need for comprehensive soil management strategies. Moreover, our examination of citizen science initiatives underscores the importance of engaging the public in soil monitoring and conservation efforts. This work emphasizes the policy relevance of promoting sustainable soil governance frameworks, supported by research, innovation, and robust soil monitoring schemes, to safeguard soil health and ensure the long-term resilience of ecosystems.
... • Drainage. Drainage is the key driver of the degradation of peat soils (Swindles et al., 2019). In the Nordic countries, between 3 % and 40 % of the original peatland area has been drained for agricultural purposes (Kløve et al., 2017;Szajdak et al., 2020). ...
... • Climate change. Climate-driven drying of European peatlands is likely to have been exacerbated by direct human impacts in recent centuries (Swindles et al., 2019). During a period of significant population growth throughout Europe (McEvedy and Jones, 1978), coupled with the expansion of cropland and intensified land use (Ramankutty and Foley, 1999), hydrological shifts took place. ...
Book
Full-text available
This report delves into the intricate interplay between drivers, pressures and impacts on soil in the 32 Member States of the European Environment Agency (EEA), along with six cooperating countries from the West Balkans, Ukraine and UK, shedding light on the multifaceted challenges facing soil conservation efforts. Our analysis shows the complex interactions among various factors, both anthropogenic and natural, shaping soil degradation processes and their subsequent consequences. We highlight key findings, including the significant impacts of soil degradation on agriculture, ecosystem resilience, water quality, biodiversity, and human health, underscoring the urgent need for comprehensive soil management strategies. Moreover, our examination of citizen science initiatives underlines the importance of engaging the public in soil monitoring and conservation efforts. This work emphasises the policy relevance of promoting sustainable soil governance frameworks, supported by research, innovation, and robust soil monitoring schemes, to safeguard soil health and ensure the long-term resilience of ecosystems.
... Thus, the presented results provide important information from the point of view of protecting naturally valuable wetlands. Especially since these areas are under very strong pressure due to climate change and human activities (Wu et al., 2016;Swindles et al., 2019). It is also worth mentioning that these results can be used to improve the estimation of the water balance in areas included in the program to restore previously drained wetlands (Ahmad et al., 2020;Günther et al., 2020;Wilson et al., 2022). ...
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The primary goal of the study is to characterize the evapotranspiration of wetlands against the background of changing meteorological conditions. The relatively long measurement period makes it possible to show the dynamics of this process both under conditions of high precipitation and periods of drought. Moreover, the analyzed period also includes measurements of evapotranspiration under conditions of rapid recovery of wetland vegetation after fire. The accomplishment of the research objectives was based on measurements using the eddy covariance method in the Biebrza National Park in northeastern Poland. The measurement period covers the years 2013–2021. Latent heat flux Qe is characterized by a distinct annual cycle with the highest values in the summer season. Average daily values of Qe from July to August were in the range of 6–10 MJ m− 2 d− 1, which is on average 60–70% of the value of the radiation balance. The relatively long measurement period showed that the evapotranspiration of the wetland surface is characterized by very high stability. The achieved values of daily as well as monthly totals during periods of drought were very close to those recorded in seasons with high precipitation. The high rate of evapotranspiration led to a decrease in groundwater levels and a significant deterioration in the water resources of the wetland environment.
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Peatlands play a key role in climate change mitigation strategies and provide multiple ecosystem services, presuming near natural, waterlogged conditions. However, there is a lack of knowledge on how spatially heterogeneous changes in climate across Europe, such as the predicted increase in drought frequency in Central Europe, might affect these ecosystem services and peatland functioning. While analysis of peat cores and moisture sensors provide high-quality insights into past or present hydrological conditions, this information is usually only available for a limited number of locations. Satellite remote sensing is an effective method to overcome this limitation, providing spatially continuous and temporally highly resolved environmental information. This study proposes to use freely available data from the Landsat Mission to analyze trends in proxies of surface moisture of European peatlands over the last four decades. Based on a large random sample of peatland sites across Europe, we performed a pixel-wise trend analysis on monthly time-series dating back to 1984 using the Normalized Difference Water Index as a moisture indicator. The satellite-derived moisture changes indicated a pronounced shift towards wetter conditions in the boreal and oceanic region of Europe, whereas in the temperate, continental region, a high proportion of peatlands experienced drying. Small-scale patterns of selected sites revealed a high spatial heterogeneity, the complexity of hydro-ecological interactions, and locally important environmental and anthropogenic drivers affecting the moisture signal. Overall, our results support the expected effects of current climate trends of increasing precipitation in boreal northern and oceanic north-western Europe and increasing frequency of drought in continental Europe. Our fully reproducible approach provided new insights on continental and local scales, relevant not only to a better understanding of moisture trends in general, but also to practitioners and stakeholders in ecosystem management. It may thus contribute to developing a cost-effective long-term monitoring strategy for European peatlands.
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