Open Access

Dendrochronology and extreme pointer years in the tree-ring record (AD 1951–2011) of polar willow from southwestern Spitsbergen (Svalbard, Norway)

Piotr Owczarek
Piotr Owczarek
 and 
Magdalena Opała
Magdalena Opała
   | Jun 13, 2016
Geochronometria's Cover Image
About this article
Previous Article
Next Article
Cite
Article Category: Research Article
Published Online: Jun 13, 2016
Page range: 84 - 95
Received: Oct 01, 2015
Accepted: Apr 21, 2016
DOI: https://doi.org/10.1515/geochr-2015-0035
Keywords
© 2016 P. Owczarek and M. Opała
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Location map showing the sampling sites in the southwestern Spitsbergen in the vicinity of the Polish Polar Station in Hornsund.
Location map showing the sampling sites in the southwestern Spitsbergen in the vicinity of the Polish Polar Station in Hornsund.

General view on the typical sampling area in northwestern shore ofHornsund fjord; flat raised marine terraces with tundra vegetation are visible in the foreground.
General view on the typical sampling area in northwestern shore ofHornsund fjord; flat raised marine terraces with tundra vegetation are visible in the foreground.

Course of annual mean air temperature and precipitation totals in the Polish Polar Station, Hornsund (77°N, 15°E) (source: Marsz and Styszyńska, 2013).
Course of annual mean air temperature and precipitation totals in the Polish Polar Station, Hornsund (77°N, 15°E) (source: Marsz and Styszyńska, 2013).

Summary of climate at the meteorological station in the Polish Polar Station, Hornsund (77°N, 15°E) (source: Marsz and Styszyńska, 2013).
Summary of climate at the meteorological station in the Polish Polar Station, Hornsund (77°N, 15°E) (source: Marsz and Styszyńska, 2013).

A. Small colony of Salix polaris (Wahlenb.) on the flat raised marine terrace surface (camera lens cap scale); B. Cross-section of 14-years old S. polaris, high variability of growth-ring width is clearly visible.
A. Small colony of Salix polaris (Wahlenb.) on the flat raised marine terrace surface (camera lens cap scale); B. Cross-section of 14-years old S. polaris, high variability of growth-ring width is clearly visible.

Individual plant chronology of 38 year old Salix polaris created on the basis of serial sectioning (after Owczarek et al. (2014a) modified).
Individual plant chronology of 38 year old Salix polaris created on the basis of serial sectioning (after Owczarek et al. (2014a) modified).

Growth-ring chronology of Salix polaris (solid line) and its sample replication (dashed line).
Growth-ring chronology of Salix polaris (solid line) and its sample replication (dashed line).

Mean, minimum and maximum grow-ring widths variability of Salix polaris samples used in the constructed chronology.
Mean, minimum and maximum grow-ring widths variability of Salix polaris samples used in the constructed chronology.

Annual course of daily mean air temperature and number of hours with liquid precipitation in 2010 in the Polish Polar Station, Hornsund (GLACIO-TOPOCLIM Database, 2014).
Annual course of daily mean air temperature and number of hours with liquid precipitation in 2010 in the Polish Polar Station, Hornsund (GLACIO-TOPOCLIM Database, 2014).

Tree-ring chronologies for different location of North Atlantic sector, including southwestern Spitsbergen and north coast of Eurasia: A — Salix polaris from Svalbard (this study), B — Betula pubescens from Troms Region, northern Norway (Opala et al. 2014), C — Salix lanata from Nenets Autonomous Okrug, northwest Russia (ITRDB, 2015a and Forbes et al., 2010), D — Pinus sylvestris from Kola Peninsula, northwest Russia (ITRDB, 2015b and Gervais and MacDonald, 2000). Black circles indicate negative pointer years common within all chronologies. Red circles indicate negative pointer years present only in single locations (not observed in Hornsund site).
Tree-ring chronologies for different location of North Atlantic sector, including southwestern Spitsbergen and north coast of Eurasia: A — Salix polaris from Svalbard (this study), B — Betula pubescens from Troms Region, northern Norway (Opala et al. 2014), C — Salix lanata from Nenets Autonomous Okrug, northwest Russia (ITRDB, 2015a and Forbes et al., 2010), D — Pinus sylvestris from Kola Peninsula, northwest Russia (ITRDB, 2015b and Gervais and MacDonald, 2000). Black circles indicate negative pointer years common within all chronologies. Red circles indicate negative pointer years present only in single locations (not observed in Hornsund site).

Statistics for polar willow growth-ring chronology.

Parameter
Time period (>3series)1951–2011
Chronology length (>3series)60
Number of series21
Mean series length38
Mean growth-ring width (Standard deviation) (mm)0.14 (0.08)
Mean index (Standard deviation)0.96 (0.58)
Mean series correlation with master0.44
Mean inter-series correlation (Rbar)0.32
Expressed population signal (EPS)0.82
Mean sensitivity0.56
Autocorrelation 1storder, unfiltered / filtered0.27/-0.01

Values of trend coefficients of climate and tree-ring variables and their statistical characteristics.

VariableTrend coefficientRR2p<NTrend per decade
Mean growth ring width1.20 (± 0.50)0.330.110.0195012.0 μm
Maximum growth ring width3.50 (± 1.10)0.420.170.0035035.0 μm
Annual air temperature0.10 (± 0.02)0.700.490.000341.1 °C
Annual precipitation4.27 (± 1.51)0.450.200.0083442.7 mm

Climatic conditions of the negative pointer years.

YearThe annual air temperature of the previous yearAbsolute minima of air temperatureNumber of days with positive mean diurnal air temperature in winter (Jan-Feb)Totals of atmospheric precipitation in MayPercentage of relative sunshine duration in JulySunshine duration in JulyMean thickness of snow cover in JanuaryMean thickness of snow cover in MayMean thickness of snow cover in JuneNumber of days with snow cover in June
(°C)(°C)(mm)(%)(hours)(cm)(cm)(cm)
Reference period means1978-2012-4.1-26.93.320.120.9155.417.928.413.813.8
Negative pointer years1958--24.8---104.2----
1967----------
1975----------
1980-6.2-30.259.115.5115.017442110
1981-5.8-35.9026.319.5145.27403530
1989-7.3-28.505.29.872.722700
1999-4.9-22.9111.221.5159.8141164
2006-2.6-20.51545.67.153.010500
2010-2.7-23.7920.310.678.92113510
eISSN:
1897-1695
Language:
English
Publication timeframe:
Volume Open
Journal Subjects:
Geosciences, other
Journal RSS Feed