Extra data for the tree ring data set SWENAMD1.RWL, 5 May 1997
Extra data for the tree ring data set SWENAMD1.RWL (later named Swed302 by ITRDB)
Date: 5 May 1997.
Name of site: Namdo (Naemdoe) (Namdo is one of the larger islands in the archipelago East of Stockholm.) Site code (given by the investigator): NAMDO Elevation (in meters): Between 10 and 50 meters. Latitude: 59 deg, 12 min North Longitude: 18 deg, 42 min East. Species code (the ITRDB will supply this): PISY = The normal pine growing here, I think it is "Scotch pine". Species name: Scotch pine Measurement type: Total ring width. Chronology type (if a chronology was developed): only raw measurement data First year: 1588 Last year: 1995 Names of investigators: Lars-Ake Larsson, Palnasvagen 1, S-133 33 Saltsjobaden, Sweden Tel +46 - 8 - 717 62 10 Fax ...[removed] email address: [removed]
Comments to the data set:
Most data is based on cores taken from living trees. The oldest tree found was 412 years old. Many other trees found, were probably of the same age but they were rotten in the middle of the trunk.
The following samples are based on living trees:
All samples with a code starting with "NA0", "NM0", "NM3" and "NMHEL". Also the samples 6680 and 6682 are from living trees. Many samples in this group have not been fully measured, i.e. only that part which is nearest to the middle of the log has been measured. The rings in the outer part were then only counted.
Most of these samples are taken from trees in dry areas on the top of small mountains where trees have been left from lumbering. Some samples are taken from bog areas where trees are growing very slowly.
The sample NMSHP1 is taken from a ship, which is probably built in the area. NMBRG is taken from a log in the remainder of a fishing bridge.
All the other samples are from two houses and from free wood pieces found. KGRINx is from an old gatepost where the wood was extremely conserved by lots of resin.
Measurement has been done with an HP Scanjet colour scanner with a resolution of 600 dpi, giving a resolution of at best 0.04 mm. Before scanning, most samples have been examined under a microscope with 20 times magnification. Every 5th ring was then marked with a pencil to avoid missing any ring when doing the actual registration/measurement from the scanned image. All (!) data from samples have been printed as curves and visually checked towards the successively developed reference curve.
Samples which have a very bad matching towards the reference curve have been excluded from the data set!
The job has been done with software which I have written myself (in C). (Later I found the ITRDB software on the Internet.)
/Lars-Ake Larsson (5 May 1997)