The potential of using Pinus sylvestris L. from the High Coast region as a climate proxy for studying hydroclimatic variability
Abstract
It is of importance to get more detailed information on past spatio-temporal hydroclimatic
changes in northern latitudes to understand the hydroclimatic regimes working there. This can
be done by studying proxy data from tree rings. One place suitable for such research is the High
Coast region which has many sites with thin soil cover on bedrock and therefore has low water
storage capacity. Thus, trees growing here are dependent on precipitation and sensitive to
drought events. Furthermore, the most common tree species here is Scots pine (Pinus sylvestris
L.) which is a drought sensitive species and commonly used within the field of
dendrochronology. The aim of this thesis was to examine the potential of using Scots pine from
the High Coast region as a climate proxy. This was done by dating and measuring the tree-ring
widths and calibrating these against precipitation, temperature, and the drought index
Standardised Precipitation-Evapotranspiration index (SPEI). The dated samples expanded the
existing swed324 chronology that previously stretched between 1448–1998 to 1403–1998 (i.e.,
45 years) and further complemented the sample depth by 18 samples which gave it a higher
reliability. The sample depth has especially been strengthened between 1480 and 1700 (i.e.,
220 years). The results showed the strongest correlation with SPEI in the period of 1901-1998
for the month of June. Furthermore, the calibration between the tree-ring width, temperature
and precipitation (1860-1998) showed a slightly lower correlation, although a significant
climate signal could be found. Lastly the results showed a potential of tree-ring research in this
region, which suggests further studies with methods such as blue intensity will be necessary to
enhance the signal.
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Date
2023-08-21Author
Ahlin, Elinor
Hägglund, Stefan
Keywords
Dendrochronology
Tree rings
Pinus sylvestris L
Sample depth
Climate correlation
Series/Report no.
B1260
Language
eng