Reconstruction of Holocene hydroclimatic variability in subarctic treeline lakes using lake sediment grain-size end-members
Current climate trends are expected to result in the northward expansion of the subarctic treeline leading to changes in vegetation cover and permafrost distribution, as they did during the Holocene Climate Optimum when the treeline was 150 km north of its current position. The impacts of these chan...
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Online Access: | http://dx.doi.org/10.1177/0959683617752836 http://journals.sagepub.com/doi/pdf/10.1177/0959683617752836 http://journals.sagepub.com/doi/full-xml/10.1177/0959683617752836 |
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crsagepubl:10.1177/0959683617752836 2023-05-15T16:37:46+02:00 Reconstruction of Holocene hydroclimatic variability in subarctic treeline lakes using lake sediment grain-size end-members Macumber, Andrew L Patterson, R Timothy Galloway, Jennifer M Falck, Hendrik Swindles, Graeme T 2018 http://dx.doi.org/10.1177/0959683617752836 http://journals.sagepub.com/doi/pdf/10.1177/0959683617752836 http://journals.sagepub.com/doi/full-xml/10.1177/0959683617752836 en eng SAGE Publications http://journals.sagepub.com/page/policies/text-and-data-mining-license The Holocene volume 28, issue 6, page 845-857 ISSN 0959-6836 1477-0911 Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change journal-article 2018 crsagepubl https://doi.org/10.1177/0959683617752836 2022-09-21T19:50:44Z Current climate trends are expected to result in the northward expansion of the subarctic treeline leading to changes in vegetation cover and permafrost distribution, as they did during the Holocene Climate Optimum when the treeline was 150 km north of its current position. The impacts of these changes on the region’s hydrology are still poorly understood. The grain-size distributions of treeline lake sediments provide an important proxy related to spring melt conditions that can be used to reconstruct hydroclimatic variability. End-member mixing analysis was used to model depositional end-members in 55 modern lake sediment samples and two sediment cores spanning the mid- to late Holocene collected from above and below the treeline in the central Northwest Territories, Canada. Cold climatic intervals (e.g. ‘Dark Ages Cold Period’, ‘Little Ice Age’) were characterised by an increase in the very coarse silt and the fine sand end-members. This was interpreted to be a response to degradation of vegetation cover and/or permafrost development. We observed increases in fine and coarse silt end-members during warmer climatic intervals (e.g. Medieval Climate Anomaly) and over the past c. 300 yr BP. This pattern is probably the result of extended melt seasons, with greater losses to evaporation and increased infiltration. The most pronounced palaeo-hydroclimatological change over the past c. 8000 yr BP was the abrupt increase in a very coarse silt end-member (mode = 50–200 µm) at c. 6300 yr BP. We interpreted the sedimentological change as an increase in winter precipitation and more energetic spring melt conditions, leading to the spring melt becoming the dominant lacustrine sediment delivery mechanism. These results place modern hydrological changes in a millennial context and show that analysis of temporal changes in the hydroclimatological system can provide insight into the future states of these sensitive subarctic ecosystems. Article in Journal/Newspaper Ice Northwest Territories permafrost Subarctic SAGE Publications (via Crossref) Canada Northwest Territories The Holocene 28 6 845 857 |
institution |
Open Polar |
collection |
SAGE Publications (via Crossref) |
op_collection_id |
crsagepubl |
language |
English |
topic |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
spellingShingle |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change Macumber, Andrew L Patterson, R Timothy Galloway, Jennifer M Falck, Hendrik Swindles, Graeme T Reconstruction of Holocene hydroclimatic variability in subarctic treeline lakes using lake sediment grain-size end-members |
topic_facet |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
description |
Current climate trends are expected to result in the northward expansion of the subarctic treeline leading to changes in vegetation cover and permafrost distribution, as they did during the Holocene Climate Optimum when the treeline was 150 km north of its current position. The impacts of these changes on the region’s hydrology are still poorly understood. The grain-size distributions of treeline lake sediments provide an important proxy related to spring melt conditions that can be used to reconstruct hydroclimatic variability. End-member mixing analysis was used to model depositional end-members in 55 modern lake sediment samples and two sediment cores spanning the mid- to late Holocene collected from above and below the treeline in the central Northwest Territories, Canada. Cold climatic intervals (e.g. ‘Dark Ages Cold Period’, ‘Little Ice Age’) were characterised by an increase in the very coarse silt and the fine sand end-members. This was interpreted to be a response to degradation of vegetation cover and/or permafrost development. We observed increases in fine and coarse silt end-members during warmer climatic intervals (e.g. Medieval Climate Anomaly) and over the past c. 300 yr BP. This pattern is probably the result of extended melt seasons, with greater losses to evaporation and increased infiltration. The most pronounced palaeo-hydroclimatological change over the past c. 8000 yr BP was the abrupt increase in a very coarse silt end-member (mode = 50–200 µm) at c. 6300 yr BP. We interpreted the sedimentological change as an increase in winter precipitation and more energetic spring melt conditions, leading to the spring melt becoming the dominant lacustrine sediment delivery mechanism. These results place modern hydrological changes in a millennial context and show that analysis of temporal changes in the hydroclimatological system can provide insight into the future states of these sensitive subarctic ecosystems. |
format |
Article in Journal/Newspaper |
author |
Macumber, Andrew L Patterson, R Timothy Galloway, Jennifer M Falck, Hendrik Swindles, Graeme T |
author_facet |
Macumber, Andrew L Patterson, R Timothy Galloway, Jennifer M Falck, Hendrik Swindles, Graeme T |
author_sort |
Macumber, Andrew L |
title |
Reconstruction of Holocene hydroclimatic variability in subarctic treeline lakes using lake sediment grain-size end-members |
title_short |
Reconstruction of Holocene hydroclimatic variability in subarctic treeline lakes using lake sediment grain-size end-members |
title_full |
Reconstruction of Holocene hydroclimatic variability in subarctic treeline lakes using lake sediment grain-size end-members |
title_fullStr |
Reconstruction of Holocene hydroclimatic variability in subarctic treeline lakes using lake sediment grain-size end-members |
title_full_unstemmed |
Reconstruction of Holocene hydroclimatic variability in subarctic treeline lakes using lake sediment grain-size end-members |
title_sort |
reconstruction of holocene hydroclimatic variability in subarctic treeline lakes using lake sediment grain-size end-members |
publisher |
SAGE Publications |
publishDate |
2018 |
url |
http://dx.doi.org/10.1177/0959683617752836 http://journals.sagepub.com/doi/pdf/10.1177/0959683617752836 http://journals.sagepub.com/doi/full-xml/10.1177/0959683617752836 |
geographic |
Canada Northwest Territories |
geographic_facet |
Canada Northwest Territories |
genre |
Ice Northwest Territories permafrost Subarctic |
genre_facet |
Ice Northwest Territories permafrost Subarctic |
op_source |
The Holocene volume 28, issue 6, page 845-857 ISSN 0959-6836 1477-0911 |
op_rights |
http://journals.sagepub.com/page/policies/text-and-data-mining-license |
op_doi |
https://doi.org/10.1177/0959683617752836 |
container_title |
The Holocene |
container_volume |
28 |
container_issue |
6 |
container_start_page |
845 |
op_container_end_page |
857 |
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1766028067903373312 |