Tundra shrub ring widths in microns, North Slope Alaska 1965-2013

Thermokarst disturbance in permafrost landscapes is likely to increase across the tundra biome with climate warming, resulting in changes to topography, vegetation, and biogeochemical cycling. Tundra shrubs grow on permafrost, but shrub - thermokarst relationships are rarely studied in detail. Since...

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Main Author: Diane Huebner
Format: Dataset
Language:unknown
Published: Arctic Data Center 2022
Subjects:
Online Access:https://doi.org/10.18739/A2FX7402S
id dataone:doi:10.18739/A2FX7402S
record_format openpolar
spelling dataone:doi:10.18739/A2FX7402S 2024-06-03T18:46:47+00:00 Tundra shrub ring widths in microns, North Slope Alaska 1965-2013 Diane Huebner Lake I-minus 1 Lake NE14 ENVELOPE(-149.55,-149.55,68.55,68.55) BEGINDATE: 1965-01-01T00:00:00Z ENDDATE: 2013-01-01T00:00:00Z 2022-01-01T00:00:00Z https://doi.org/10.18739/A2FX7402S unknown Arctic Data Center climate sensitivity microsite retrogressive thaw slump secondary growth shrubs tundra Salix pulchra Salix glauca Betula nana Dataset 2022 dataone:urn:node:ARCTIC https://doi.org/10.18739/A2FX7402S 2024-06-03T18:18:12Z Thermokarst disturbance in permafrost landscapes is likely to increase across the tundra biome with climate warming, resulting in changes to topography, vegetation, and biogeochemical cycling. Tundra shrubs grow on permafrost, but shrub - thermokarst relationships are rarely studied in detail. Since the 1980’s, Alaska’s North Slope has experienced increased thermokarst activity, including retrogressive thaw slumps (RTS) on hillslopes. Within decades, RTSs near Toolik Lake, Alaska, were colonized by tall (≥ 0.5 meters (m)) deciduous shrubs. We used dendrochronology methods on 66 shrubs (182 stem cross sections) representing dominant deciduous species: willows (Salix pulchra and Salix glauca) and dwarf birch (Betula nana) at two RTS chronosequences on Alaska’s North Slope comprising seven sites, to quantify thermokarst and climate effects (25 years of temperature and precipitation records) on shrub secondary growth (i.e., annual rings) in RTS-disturbed and undisturbed moist acidic tussock (MAT) tundra. Across species, average growth ring widths were 2 x wider for shrubs in RTSs than in MAT, and ring widths decreased with RTS age. A 1 degree Celsius (°C) June temperature increase was associated with 2% wider rings across species and sites, but shrubs showed marginal growth in warmer summers, supporting tundra-wide shrub climate sensitivity studies. A 4.5% average ring width increase per 1 mm of previous year’s September precipitation was seen in shrubs in mid-successional RTSs, suggesting protective effects of early snowfall in RTSs versus open tundra. RTS age category explained 47% and 30% of average ring width variance of willows and dwarf birch, respectively, in linear mixed effects models. Climate variables explained 2% average ring width variance across species. Our results suggest that RTS exert strong successional effects on tundra shrub growth. Climate effects appear to show weaker synoptic patterns across the study area. RTS will likely contribute to tundra greening where RTS activity is increasing. Dataset Betula nana Dwarf birch north slope permafrost Thermokarst Tundra Alaska Arctic Data Center (via DataONE) ENVELOPE(-149.55,-149.55,68.55,68.55)
institution Open Polar
collection Arctic Data Center (via DataONE)
op_collection_id dataone:urn:node:ARCTIC
language unknown
topic climate sensitivity
microsite
retrogressive thaw slump
secondary growth
shrubs
tundra
Salix pulchra
Salix glauca
Betula nana
spellingShingle climate sensitivity
microsite
retrogressive thaw slump
secondary growth
shrubs
tundra
Salix pulchra
Salix glauca
Betula nana
Diane Huebner
Tundra shrub ring widths in microns, North Slope Alaska 1965-2013
topic_facet climate sensitivity
microsite
retrogressive thaw slump
secondary growth
shrubs
tundra
Salix pulchra
Salix glauca
Betula nana
description Thermokarst disturbance in permafrost landscapes is likely to increase across the tundra biome with climate warming, resulting in changes to topography, vegetation, and biogeochemical cycling. Tundra shrubs grow on permafrost, but shrub - thermokarst relationships are rarely studied in detail. Since the 1980’s, Alaska’s North Slope has experienced increased thermokarst activity, including retrogressive thaw slumps (RTS) on hillslopes. Within decades, RTSs near Toolik Lake, Alaska, were colonized by tall (≥ 0.5 meters (m)) deciduous shrubs. We used dendrochronology methods on 66 shrubs (182 stem cross sections) representing dominant deciduous species: willows (Salix pulchra and Salix glauca) and dwarf birch (Betula nana) at two RTS chronosequences on Alaska’s North Slope comprising seven sites, to quantify thermokarst and climate effects (25 years of temperature and precipitation records) on shrub secondary growth (i.e., annual rings) in RTS-disturbed and undisturbed moist acidic tussock (MAT) tundra. Across species, average growth ring widths were 2 x wider for shrubs in RTSs than in MAT, and ring widths decreased with RTS age. A 1 degree Celsius (°C) June temperature increase was associated with 2% wider rings across species and sites, but shrubs showed marginal growth in warmer summers, supporting tundra-wide shrub climate sensitivity studies. A 4.5% average ring width increase per 1 mm of previous year’s September precipitation was seen in shrubs in mid-successional RTSs, suggesting protective effects of early snowfall in RTSs versus open tundra. RTS age category explained 47% and 30% of average ring width variance of willows and dwarf birch, respectively, in linear mixed effects models. Climate variables explained 2% average ring width variance across species. Our results suggest that RTS exert strong successional effects on tundra shrub growth. Climate effects appear to show weaker synoptic patterns across the study area. RTS will likely contribute to tundra greening where RTS activity is increasing.
format Dataset
author Diane Huebner
author_facet Diane Huebner
author_sort Diane Huebner
title Tundra shrub ring widths in microns, North Slope Alaska 1965-2013
title_short Tundra shrub ring widths in microns, North Slope Alaska 1965-2013
title_full Tundra shrub ring widths in microns, North Slope Alaska 1965-2013
title_fullStr Tundra shrub ring widths in microns, North Slope Alaska 1965-2013
title_full_unstemmed Tundra shrub ring widths in microns, North Slope Alaska 1965-2013
title_sort tundra shrub ring widths in microns, north slope alaska 1965-2013
publisher Arctic Data Center
publishDate 2022
url https://doi.org/10.18739/A2FX7402S
op_coverage Lake I-minus 1
Lake NE14
ENVELOPE(-149.55,-149.55,68.55,68.55)
BEGINDATE: 1965-01-01T00:00:00Z ENDDATE: 2013-01-01T00:00:00Z
long_lat ENVELOPE(-149.55,-149.55,68.55,68.55)
genre Betula nana
Dwarf birch
north slope
permafrost
Thermokarst
Tundra
Alaska
genre_facet Betula nana
Dwarf birch
north slope
permafrost
Thermokarst
Tundra
Alaska
op_doi https://doi.org/10.18739/A2FX7402S
_version_ 1800871037605249024