Publications by category
Journal articles
Sim T, Swindles G, Morris P, Baird A, Cooper C, Gallego-Sala A, Charman D, Roland T, Borken W, Mullan D, et al (In Press). Divergent responses of permafrost peatlands to recent climate change.
Abstract:
Divergent responses of permafrost peatlands to recent climate change
<p>Permafrost peatlands are found in high-latitude regions and store globally-important amounts of soil organic carbon. These regions are warming at over twice the global average rate, causing permafrost thaw and exposing previously inert carbon to decomposition and emission to the atmosphere as greenhouse gases. However, it is unclear how peatland hydrological behaviour, vegetation structure and carbon balance, and the linkages between them, will respond to permafrost thaw in a warming climate. Here we show that permafrost peatlands follow divergent ecohydrological trajectories in response to recent climate change within the same rapidly warming region (northern Sweden). Whether a site becomes wetter or drier depends on local factors and the autogenic response of individual peatlands. We find that bryophyte-dominated vegetation demonstrates resistance, and in some cases resilience, to climatic and hydrological shifts. Drying at four sites is clearly associated with reduced carbon sequestration, while no clear relationship at wetting sites is observed. We highlight the complex dynamics of permafrost peatlands and warn against an overly-simple approach when considering their ecohydrological trajectories and role as C sinks under a warming climate.   </p>
Abstract.
Galka M, Kolaczek P, Sim TG, Knorr K-H, Niedzielski P, Lewandowska A, Szczurek G (2022). Palaeoenvironmental conditions and human activity in the vicinity of the Grodzisko fortified settlement (central Europe, Poland) from the late-Neolithic to the Roman period.
GEOARCHAEOLOGY-AN INTERNATIONAL JOURNAL,
37(2), 385-399.
Author URL.
Zhang H, Väliranta M, Swindles GT, Aquino-López MA, Mullan D, Tan N, Amesbury M, Babeshko KV, Bao K, Bobrov A, et al (2022). Recent climate change has driven divergent hydrological shifts in high-latitude peatlands.
Nat Commun,
13(1).
Abstract:
Recent climate change has driven divergent hydrological shifts in high-latitude peatlands.
High-latitude peatlands are changing rapidly in response to climate change, including permafrost thaw. Here, we reconstruct hydrological conditions since the seventeenth century using testate amoeba data from 103 high-latitude peat archives. We show that 54% of the peatlands have been drying and 32% have been wetting over this period, illustrating the complex ecohydrological dynamics of high latitude peatlands and their highly uncertain responses to a warming climate.
Abstract.
Author URL.
Galka M, Feurdean A, Sim TG, Tobolski K, Aunina L, Apolinarska K (2021). A multi-proxy long-term ecological investigation into the development of a late Holocene calcareous spring-fed fen ecosystem (Raganu Mire) and boreal forest at the SE Baltic coast (Latvia).
ECOLOGICAL INDICATORS,
126 Author URL.
Sim TG, Swindles GT, Morris PJ, Baird AJ, Cooper CL, Gallego-Sala AV, Charman DJ, Roland TP, Borken W, Mullan DJ, et al (2021). Divergent responses of permafrost peatlands to recent climate change.
Environmental Research Letters,
16(3), 034001-034001.
Abstract:
Divergent responses of permafrost peatlands to recent climate change
Abstract
. Permafrost peatlands are found in high-latitude regions and store globally-important amounts of soil organic carbon. These regions are warming at over twice the global average rate, causing permafrost thaw, and exposing previously inert carbon to decomposition and emission to the atmosphere as greenhouse gases. However, it is unclear how peatland hydrological behaviour, vegetation structure and carbon balance, and the linkages between them, will respond to permafrost thaw in a warming climate. Here we show that permafrost peatlands follow divergent ecohydrological trajectories in response to recent climate change within the same rapidly warming region (northern Sweden). Whether a site becomes wetter or drier depends on local factors and the autogenic response of individual peatlands. We find that bryophyte-dominated vegetation demonstrates resistance, and in some cases resilience, to climatic and hydrological shifts. Drying at four sites is clearly associated with reduced carbon sequestration, while no clear relationship at wetting sites is observed. We highlight the complex dynamics of permafrost peatlands and warn against an overly-simple approach when considering their ecohydrological trajectories and role as C sinks under a warming climate.
Abstract.
Sim TG, Swindles GT, Morris PJ, Baird AJ, Charman DJ, Amesbury MJ, Beilman D, Channon A, Gallego-Sala AV (2021). Ecology of peatland testate amoebae in Svalbard and the development of transfer functions for reconstructing past water-table depth and pH.
Ecological Indicators,
131Abstract:
Ecology of peatland testate amoebae in Svalbard and the development of transfer functions for reconstructing past water-table depth and pH
Peatlands are valuable archives of information about past environmental conditions and represent a globally-important carbon store. Robust proxy methods are required to reconstruct past ecohydrological dynamics in high-latitude peatlands to improve our understanding of change in these carbon-rich ecosystems. The High Arctic peatlands in Svalbard are at the northern limit of current peatland distribution and have experienced rapidly rising temperatures of 0.81 °C per decade since 1958. We examine the ecology of peatland testate amoebae in surface vegetation samples from permafrost peatlands on Spitsbergen, the largest island of the Svalbard archipelago, and develop new transfer functions to reconstruct water-table depth (WTD) and pH that can be applied to understand past peatland ecosystem dynamics in response to climate change. These transfer functions are the first of their kind for peatlands in Svalbard and the northernmost developed to date. Multivariate statistical analysis shows that WTD and pore water pH are the dominant controls on testate amoeba species distribution. This finding is consistent with results from peatlands in lower latitudes with regard to WTD and supports work showing that when samples are taken across a long enough trophic gradient, peatland trophic status is an important control on the distribution of testate amoebae. No differences were found between transfer functions including and excluding the taxa with weak idiosomic tests (WISTs) that are most susceptible to decay. The final models for application to fossil samples therefore excluded these taxa. The WTD transfer function demonstrates the best performance (R2LOO = 0.719, RMSEPLOO = 3.2 cm), but the pH transfer function also performs well (R2LOO = 0.690, RMSEPLOO = 0.320). The transfer functions were applied to a core from western Spitsbergen and suggest drying conditions ~1750 CE, followed by a trend of recent wetting and increasing pH from ~1920 CE. These new transfer functions allow the reconstruction of past peatland WTD and pH in Svalbard, thereby enabling a greater understanding of long-term ecohydrological dynamics in these rapidly changing ecosystems.
Abstract.
Wolstenholme JM, Smith MW, Baird AJ, Sim TG (2020). A new approach for measuring surface hydrological connectivity.
HYDROLOGICAL PROCESSES,
34(3), 538-552.
Author URL.
Galka M, Lewandowska A, Niedzielski P, Sim TG, Swindles GT, Szczurek G (2020). Late Glacial and early Holocene development of an oxbow lake in Central Europe (Poland) based on plant macrofossil and geochemical data.
HOLOCENE,
30(1), 178-189.
Author URL.
Swindles GT, Roland TP, Amesbury MJ, Lamentowicz M, McKeown MM, Sim TG, Fewster RE, Mitchell EAD (2020). Quantifying the effect of testate amoeba decomposition on peat-based water-table reconstructions. European Journal of Protistology, 74, 125693-125693.
Sim TG, Swindles GT, Morris PJ, Galka M, Mullan D, Galloway JM (2019). Pathways for Ecological Change in Canadian High Arctic Wetlands Under Rapid Twentieth Century Warming.
GEOPHYSICAL RESEARCH LETTERS,
46(9), 4726-4737.
Author URL.
Swindles GT, Outram Z, Batt CM, Hamilton WD, Church MJ, Bond JM, Watson EJ, Cook GT, Sim TG, Newton AJ, et al (2019). Vikings, peat formation and settlement abandonment: a multi-method chronological approach from Shetland.
QUATERNARY SCIENCE REVIEWS,
210, 211-225.
Author URL.
Swindles GT, Morris PJ, Mullan DJ, Payne RJ, Roland TP, Amesbury MJ, Lamentowicz M, Turner TE, Gallego-Sala A, Sim T, et al (2019). Widespread drying of European peatlands in recent centuries. Nature Geoscience, 12(11), 922-928.
Publications by year
In Press
Sim T, Swindles G, Morris P, Baird A, Cooper C, Gallego-Sala A, Charman D, Roland T, Borken W, Mullan D, et al (In Press). Divergent responses of permafrost peatlands to recent climate change.
Abstract:
Divergent responses of permafrost peatlands to recent climate change
<p>Permafrost peatlands are found in high-latitude regions and store globally-important amounts of soil organic carbon. These regions are warming at over twice the global average rate, causing permafrost thaw and exposing previously inert carbon to decomposition and emission to the atmosphere as greenhouse gases. However, it is unclear how peatland hydrological behaviour, vegetation structure and carbon balance, and the linkages between them, will respond to permafrost thaw in a warming climate. Here we show that permafrost peatlands follow divergent ecohydrological trajectories in response to recent climate change within the same rapidly warming region (northern Sweden). Whether a site becomes wetter or drier depends on local factors and the autogenic response of individual peatlands. We find that bryophyte-dominated vegetation demonstrates resistance, and in some cases resilience, to climatic and hydrological shifts. Drying at four sites is clearly associated with reduced carbon sequestration, while no clear relationship at wetting sites is observed. We highlight the complex dynamics of permafrost peatlands and warn against an overly-simple approach when considering their ecohydrological trajectories and role as C sinks under a warming climate.   </p>
Abstract.
2022
Galka M, Kolaczek P, Sim TG, Knorr K-H, Niedzielski P, Lewandowska A, Szczurek G (2022). Palaeoenvironmental conditions and human activity in the vicinity of the Grodzisko fortified settlement (central Europe, Poland) from the late-Neolithic to the Roman period.
GEOARCHAEOLOGY-AN INTERNATIONAL JOURNAL,
37(2), 385-399.
Author URL.
Zhang H, Väliranta M, Swindles GT, Aquino-López MA, Mullan D, Tan N, Amesbury M, Babeshko KV, Bao K, Bobrov A, et al (2022). Recent climate change has driven divergent hydrological shifts in high-latitude peatlands.
Nat Commun,
13(1).
Abstract:
Recent climate change has driven divergent hydrological shifts in high-latitude peatlands.
High-latitude peatlands are changing rapidly in response to climate change, including permafrost thaw. Here, we reconstruct hydrological conditions since the seventeenth century using testate amoeba data from 103 high-latitude peat archives. We show that 54% of the peatlands have been drying and 32% have been wetting over this period, illustrating the complex ecohydrological dynamics of high latitude peatlands and their highly uncertain responses to a warming climate.
Abstract.
Author URL.
2021
Galka M, Feurdean A, Sim TG, Tobolski K, Aunina L, Apolinarska K (2021). A multi-proxy long-term ecological investigation into the development of a late Holocene calcareous spring-fed fen ecosystem (Raganu Mire) and boreal forest at the SE Baltic coast (Latvia).
ECOLOGICAL INDICATORS,
126 Author URL.
Sim TG, Swindles GT, Morris PJ, Baird AJ, Cooper CL, Gallego-Sala AV, Charman DJ, Roland TP, Borken W, Mullan DJ, et al (2021). Divergent responses of permafrost peatlands to recent climate change.
Environmental Research Letters,
16(3), 034001-034001.
Abstract:
Divergent responses of permafrost peatlands to recent climate change
Abstract
. Permafrost peatlands are found in high-latitude regions and store globally-important amounts of soil organic carbon. These regions are warming at over twice the global average rate, causing permafrost thaw, and exposing previously inert carbon to decomposition and emission to the atmosphere as greenhouse gases. However, it is unclear how peatland hydrological behaviour, vegetation structure and carbon balance, and the linkages between them, will respond to permafrost thaw in a warming climate. Here we show that permafrost peatlands follow divergent ecohydrological trajectories in response to recent climate change within the same rapidly warming region (northern Sweden). Whether a site becomes wetter or drier depends on local factors and the autogenic response of individual peatlands. We find that bryophyte-dominated vegetation demonstrates resistance, and in some cases resilience, to climatic and hydrological shifts. Drying at four sites is clearly associated with reduced carbon sequestration, while no clear relationship at wetting sites is observed. We highlight the complex dynamics of permafrost peatlands and warn against an overly-simple approach when considering their ecohydrological trajectories and role as C sinks under a warming climate.
Abstract.
Sim TG, Swindles GT, Morris PJ, Baird AJ, Charman DJ, Amesbury MJ, Beilman D, Channon A, Gallego-Sala AV (2021). Ecology of peatland testate amoebae in Svalbard and the development of transfer functions for reconstructing past water-table depth and pH.
Ecological Indicators,
131Abstract:
Ecology of peatland testate amoebae in Svalbard and the development of transfer functions for reconstructing past water-table depth and pH
Peatlands are valuable archives of information about past environmental conditions and represent a globally-important carbon store. Robust proxy methods are required to reconstruct past ecohydrological dynamics in high-latitude peatlands to improve our understanding of change in these carbon-rich ecosystems. The High Arctic peatlands in Svalbard are at the northern limit of current peatland distribution and have experienced rapidly rising temperatures of 0.81 °C per decade since 1958. We examine the ecology of peatland testate amoebae in surface vegetation samples from permafrost peatlands on Spitsbergen, the largest island of the Svalbard archipelago, and develop new transfer functions to reconstruct water-table depth (WTD) and pH that can be applied to understand past peatland ecosystem dynamics in response to climate change. These transfer functions are the first of their kind for peatlands in Svalbard and the northernmost developed to date. Multivariate statistical analysis shows that WTD and pore water pH are the dominant controls on testate amoeba species distribution. This finding is consistent with results from peatlands in lower latitudes with regard to WTD and supports work showing that when samples are taken across a long enough trophic gradient, peatland trophic status is an important control on the distribution of testate amoebae. No differences were found between transfer functions including and excluding the taxa with weak idiosomic tests (WISTs) that are most susceptible to decay. The final models for application to fossil samples therefore excluded these taxa. The WTD transfer function demonstrates the best performance (R2LOO = 0.719, RMSEPLOO = 3.2 cm), but the pH transfer function also performs well (R2LOO = 0.690, RMSEPLOO = 0.320). The transfer functions were applied to a core from western Spitsbergen and suggest drying conditions ~1750 CE, followed by a trend of recent wetting and increasing pH from ~1920 CE. These new transfer functions allow the reconstruction of past peatland WTD and pH in Svalbard, thereby enabling a greater understanding of long-term ecohydrological dynamics in these rapidly changing ecosystems.
Abstract.
2020
Wolstenholme JM, Smith MW, Baird AJ, Sim TG (2020). A new approach for measuring surface hydrological connectivity.
HYDROLOGICAL PROCESSES,
34(3), 538-552.
Author URL.
Galka M, Lewandowska A, Niedzielski P, Sim TG, Swindles GT, Szczurek G (2020). Late Glacial and early Holocene development of an oxbow lake in Central Europe (Poland) based on plant macrofossil and geochemical data.
HOLOCENE,
30(1), 178-189.
Author URL.
Swindles GT, Roland TP, Amesbury MJ, Lamentowicz M, McKeown MM, Sim TG, Fewster RE, Mitchell EAD (2020). Quantifying the effect of testate amoeba decomposition on peat-based water-table reconstructions. European Journal of Protistology, 74, 125693-125693.
2019
Sim TG, Swindles GT, Morris PJ, Galka M, Mullan D, Galloway JM (2019). Pathways for Ecological Change in Canadian High Arctic Wetlands Under Rapid Twentieth Century Warming.
GEOPHYSICAL RESEARCH LETTERS,
46(9), 4726-4737.
Author URL.
Swindles GT, Outram Z, Batt CM, Hamilton WD, Church MJ, Bond JM, Watson EJ, Cook GT, Sim TG, Newton AJ, et al (2019). Vikings, peat formation and settlement abandonment: a multi-method chronological approach from Shetland.
QUATERNARY SCIENCE REVIEWS,
210, 211-225.
Author URL.
Swindles GT, Morris PJ, Mullan DJ, Payne RJ, Roland TP, Amesbury MJ, Lamentowicz M, Turner TE, Gallego-Sala A, Sim T, et al (2019). Widespread drying of European peatlands in recent centuries. Nature Geoscience, 12(11), 922-928.