Computer-Assisted Quality Control in Tree-Ring Dating and Measurement

Data quality control is especially important for tree -ring measurement series from non -arid regions. Since climatic factors are less often severely limiting to tree growth in these regions, ring series are less sensitive, and the climatic signal contained therein is weaker than in arid sites (Fritts 1976). In such areas it is very important to preserve as much as possible of the climatic information through accurate crossdating and measurement, with a minimum of "noise" introduced through errors. In determining the dating of tree -ring site collections from areas of somewhat difficult crossdating, an objective and efficient tool for locating errors or for confirming the crossdating would be very useful. Fritts describes some of the difficulties encountered in crossdating and emphasizes the importance of accurate dating for inferring climate from tree -rings, particularly since precise time definition is one of the advantageous qualities of dendrochronological data in comparison with most other paleoclimatic data. In addition, tree -ring series are occasionally found which though apparently of usable quality, fail to yield a conclusive crossdating match using the technique of skeleton plotting (Stokes and Smiley 1968), or by the widely used method of cross matching from memory. In such a series an injury or suppression of growth may prevent the dendrochronologist from following the dating inward from the date of collection. A new computer program for objectively checking tree -ring measurement series and aiding in the crossdating process is presented here.