Testate amoeba records indicate regional 20th-century lowering of water tables in ombrotrophic peatlands in central-northern Alberta, Canada
Testate amoebae are abundant in the surface layers of northern peatlands. Analysis of their fossilized shell (test) assemblages allows for reconstructions of local watertable depths (WTD). We have reconstructed WTD dynamics for five peat cores from peatlands ranging in distance from the Athabasca bi...
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ftunivquebec:oai:archipel.uqam.ca:13342 2023-07-16T03:58:58+02:00 Testate amoeba records indicate regional 20th-century lowering of water tables in ombrotrophic peatlands in central-northern Alberta, Canada van Bellen, Simon Magnan, Gabriel Davies, Lauren Froese, Duane Mullan-Boudreau, Gillian Zaccone, Claudio Garneau, Michelle Shotyk, William 2018-03-23 application/msword http://archipel.uqam.ca/13342/1/manuscript_depot.docx en eng http://archipel.uqam.ca/13342/ http://dx.doi.org/10.1111/gcb.14143 doi:10.1111/gcb.14143 http://archipel.uqam.ca/13342/1/manuscript_depot.docx van Bellen, Simon; Magnan, Gabriel; Davies, Lauren; Froese, Duane; Mullan-Boudreau, Gillian; Zaccone, Claudio; Garneau, Michelle et Shotyk, William (2018). « Testate amoeba records indicate regional 20th-century lowering of water tables in ombrotrophic peatlands in central-northern Alberta, Canada ». Global Change Biology, 24(7), pp. 2758-2774. Little Ice Age water table transfer function oil sands peat bog functional trait Sphagnum permafrost Article de revue scientifique PeerReviewed 2018 ftunivquebec https://doi.org/10.1111/gcb.14143 2023-06-24T23:22:54Z Testate amoebae are abundant in the surface layers of northern peatlands. Analysis of their fossilized shell (test) assemblages allows for reconstructions of local watertable depths (WTD). We have reconstructed WTD dynamics for five peat cores from peatlands ranging in distance from the Athabasca bituminous sands (ABS) region in western Canada. Amoeba assemblages were combined with plant macrofossil records, acid-insoluble ash (AIA) fluxes and instrumental climate data to identify drivers for environmental change. Two functional traits of testate amoebae, mixotrophy and the tendency to integrate xenogenic mineral matter in test construction, were quantified to infer possible effects of AIA flux on testate amoeba presence. Age–depth models showed the cores each covered at least the last ~315 years, with some spanning the last millennium. Testate amoeba assemblages were likely affected by permafrost development in two of the peatlands, yet the most important shift in assemblages was detected after 1960 CE. This shift represents a significant apparent lowering of water tables in four out of five cores, with a mean drop of ~15 cm. Over the last 50 years, assemblages shifted towards more xerophilous taxa, a trend which was best explained by increasing Sphagnum s. Acutifolia and, to a lesser extent, mean summer temperature. This trend was most evident in the two cores from the sites located farthest away from the ABS region. AIA flux variations did not show a clear effect on mineral-agglutinating taxa, nor on S. s. Acutifolia presence. We therefore suggest the drying trend was forced by the establishment of S. s. Acutifolia, driven by enhanced productivity following regional warming. Such recent apparent drying of peatlands, which may only be reconstructed by appropriate indicators combined with high chronological control, may affect vulnerability to future burning and promote emissions of CO2. Text Ice permafrost UQAM - Université du Québec à Montréal: archipel Canada Global Change Biology 24 7 2758 2774 |
institution |
Open Polar |
collection |
UQAM - Université du Québec à Montréal: archipel |
op_collection_id |
ftunivquebec |
language |
English |
topic |
Little Ice Age water table transfer function oil sands peat bog functional trait Sphagnum permafrost |
spellingShingle |
Little Ice Age water table transfer function oil sands peat bog functional trait Sphagnum permafrost van Bellen, Simon Magnan, Gabriel Davies, Lauren Froese, Duane Mullan-Boudreau, Gillian Zaccone, Claudio Garneau, Michelle Shotyk, William Testate amoeba records indicate regional 20th-century lowering of water tables in ombrotrophic peatlands in central-northern Alberta, Canada |
topic_facet |
Little Ice Age water table transfer function oil sands peat bog functional trait Sphagnum permafrost |
description |
Testate amoebae are abundant in the surface layers of northern peatlands. Analysis of their fossilized shell (test) assemblages allows for reconstructions of local watertable depths (WTD). We have reconstructed WTD dynamics for five peat cores from peatlands ranging in distance from the Athabasca bituminous sands (ABS) region in western Canada. Amoeba assemblages were combined with plant macrofossil records, acid-insoluble ash (AIA) fluxes and instrumental climate data to identify drivers for environmental change. Two functional traits of testate amoebae, mixotrophy and the tendency to integrate xenogenic mineral matter in test construction, were quantified to infer possible effects of AIA flux on testate amoeba presence. Age–depth models showed the cores each covered at least the last ~315 years, with some spanning the last millennium. Testate amoeba assemblages were likely affected by permafrost development in two of the peatlands, yet the most important shift in assemblages was detected after 1960 CE. This shift represents a significant apparent lowering of water tables in four out of five cores, with a mean drop of ~15 cm. Over the last 50 years, assemblages shifted towards more xerophilous taxa, a trend which was best explained by increasing Sphagnum s. Acutifolia and, to a lesser extent, mean summer temperature. This trend was most evident in the two cores from the sites located farthest away from the ABS region. AIA flux variations did not show a clear effect on mineral-agglutinating taxa, nor on S. s. Acutifolia presence. We therefore suggest the drying trend was forced by the establishment of S. s. Acutifolia, driven by enhanced productivity following regional warming. Such recent apparent drying of peatlands, which may only be reconstructed by appropriate indicators combined with high chronological control, may affect vulnerability to future burning and promote emissions of CO2. |
format |
Text |
author |
van Bellen, Simon Magnan, Gabriel Davies, Lauren Froese, Duane Mullan-Boudreau, Gillian Zaccone, Claudio Garneau, Michelle Shotyk, William |
author_facet |
van Bellen, Simon Magnan, Gabriel Davies, Lauren Froese, Duane Mullan-Boudreau, Gillian Zaccone, Claudio Garneau, Michelle Shotyk, William |
author_sort |
van Bellen, Simon |
title |
Testate amoeba records indicate regional 20th-century lowering of water tables in ombrotrophic peatlands in central-northern Alberta, Canada |
title_short |
Testate amoeba records indicate regional 20th-century lowering of water tables in ombrotrophic peatlands in central-northern Alberta, Canada |
title_full |
Testate amoeba records indicate regional 20th-century lowering of water tables in ombrotrophic peatlands in central-northern Alberta, Canada |
title_fullStr |
Testate amoeba records indicate regional 20th-century lowering of water tables in ombrotrophic peatlands in central-northern Alberta, Canada |
title_full_unstemmed |
Testate amoeba records indicate regional 20th-century lowering of water tables in ombrotrophic peatlands in central-northern Alberta, Canada |
title_sort |
testate amoeba records indicate regional 20th-century lowering of water tables in ombrotrophic peatlands in central-northern alberta, canada |
publishDate |
2018 |
url |
http://archipel.uqam.ca/13342/1/manuscript_depot.docx |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_relation |
http://archipel.uqam.ca/13342/ http://dx.doi.org/10.1111/gcb.14143 doi:10.1111/gcb.14143 http://archipel.uqam.ca/13342/1/manuscript_depot.docx van Bellen, Simon; Magnan, Gabriel; Davies, Lauren; Froese, Duane; Mullan-Boudreau, Gillian; Zaccone, Claudio; Garneau, Michelle et Shotyk, William (2018). « Testate amoeba records indicate regional 20th-century lowering of water tables in ombrotrophic peatlands in central-northern Alberta, Canada ». Global Change Biology, 24(7), pp. 2758-2774. |
op_doi |
https://doi.org/10.1111/gcb.14143 |
container_title |
Global Change Biology |
container_volume |
24 |
container_issue |
7 |
container_start_page |
2758 |
op_container_end_page |
2774 |
_version_ |
1771546370968125440 |