Pinus sylvestris
Pinus sylvestris, PISY, Scotch Pine is the most important specie beside Quercus robur to dendrochronology in northern Europe. A lot of chronologies are available. Pine wood is very frequently used in buildings and other constructions, which means that there is a lot of material for a dendrochronologist to work with. In for instance northern Scandinavia pine wood use to be very well preserved in constructions. The oldest buildings are from 12'th century in Norway. In Sweden there are a few known buildings from first part of the 13'th century: Granhults kyrka and Tiondeboden i Ingatorp in Småland, Eldhuset at Zorns Gammelgård in Mora.
In coast near areas and on lower latitudes and altitudes the sapwood often is affected by insects according to humidity, and therefore difficult to core. Pine stumps, sometimes high ones, may sometimes persist for hundreds of years in the forest, due to high resin content. Pine wood will also persist very well in wet conditions in lakes and bogs. It is relatively easy to collect cores from with an increment borer both from living pine trees and from old logs in a construction.
How to recognize a dendrochronological wood sample as Pinus sylvestris?
Typical for wood from Pinus (sylvestris and other species) use to be:
- A relatively distinct change from early wood to late wood in most of the rings.
- Often a lot of white "dots" in the late wood.
- The pitch use to be more "star shaped" than in Picea
- Often a reddish color on the heart wood in contrast to an more yellow (or blue or green according to affection) sap wood. But there are big variations from sample to sample and sometimes the border between sap wood and heart wood is almost invisible.
- Sometimes blue stain affects the sap wood.
- In microscope a thin wet preparation will show a typical pattern, different from other groups of conifers.
Observed problems according to measuring and crossdating PISY samples
Extremely thin or absent rings
An usual reason why a Pinus sample is not possible to cross date even than a good chronology is available are presence of too narrow rings or absent ones. In high resolution, rings sometimes are possible to see but not always also if the cellular structure is clearly seen.
External links
- Wikimedia Commons contains a media category related to sylvestris Pinus sylvestris
- Wikipedia (English) article about Pine Scots Pine
- Wikipedia (Swedish) article about Pinus sylvestris
- Wikipedia (Deutsch) article about Pinus sylvestris