Annuals rings, climate and history
by Chris, 16 June, 2011, 1 comments
Dendrochronology seeks to gather information on tree rings, dated to their year of formation, and to use this information to established the age of artefacts (like the timbers of a boat or remains of house) or determine the nature of the climate in times past.
Annual rings form in temperate trees because the xylem vessels or early wood formed in late spring and early summer (when lots of growth occurs) are wider and lighter than those formed in late summer & early autumn, which are narrower and darker (sometimes called the late wood). A light and dark ring together constitute one year’s growth. In winter, there is no growth.
The various branches of dendrochronology (dendroarchaeology, dendroclimatology) are based on the uniformitarian principle. This says that the various factors that currently influence tree growth and hence tree ring development will have operated in the past. Through knowledge of these factors (physical and biological) that have influenced current and recent tree ring growth, it is possible when looking at tree ring samples from old wood artefacts / timbers to ‘reconstruct’ the climate of the past.
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