What is tree ring dating
This variation is referred to as sensitivity and the lack of ring variability is called complacency.Trees showing sensitive rings are those affected by conditions like slope gradient, poor soils, little moisture.A large portion of the effects of nonclimatic factors that occur in the various site data is minimized by this averaging scheme.A number of computer programs are used to calculate statistical data.Checked through a variety of methods independent of tree-ring growth, this principle has proved to be valid.Review all the principles of dendrochronology as complied by Chronology Building The climatic changes or patterns in specific geographic areas can be traced by the study of old living trees.Sensitivity It is an oversimplification to say that dendrochronology is ring counting based on rainfall and the physiology of trees. This is especially true with the old bristlecones, as their growth can be affected by slope gradient, sun, wind, soil properties, temperature and snow accumulation.The more a tree's rate of growth has been limited by such environmental factors, the more variation in ring to ring growth will be present.
Additionally, the average of all data provides the best estimate of climate averages.An example of this occurred in the 1920's when expeditions led by Douglass dated Pueblo Bonito, a prehistoric native American settlement in New Mexico.By analyzing the timbers used in its construction, they determined its existence 800 years before Columbus.If a pattern of individual ring widths in the two samples prove to be identical at some point, we can carry dating further into the past.With this method of matching overlapping patterns found in different wood samples, bristlecone chronologies have been established almost 9,000 years into the past.
Call or email us for more information about dating your building. Historic Preservation Office, architectural historians with the Architectural Research Department at Colonial Williamsburg and local historians participated in the research.