With National Science Foundation support, Dr. Malcolm Hughs and his colleagues at the University of Arizona will develop a computer assisted system for tree ring dating. At the present time all dendrochronology laboratories rely solely on very time consuming but accurate manual techniques and the proposed system which would increase speed but maintain accuracy would have a major impact on the numbers of samples which could be analyzed. Because the characteristics of tree rings are affected by temperature and moisture which vary annually, rings differ in thickness from year to year and it has been possible to construct sequences which are chronologically anchored in the present extend back thousands of years in time. On this basis one can take old wood fragments (often in the form of charcoal) , match them against a master sequence and determine their absolute age. Because of geographic variation in climate, individual sequences must be constructed for different parts of the world and most laboratories work both to construct and extend master sequences as well as to date samples of unknown age. This project is important for two reasons. The first involves its broad scientific impact. A broad range of scientists includingarchaeologists, paleobiologists, ecologists, geologists and climatologists require accurate dating of past events and dendrochronology provides such information. For example, scientists use such data to study rates of ecological succession and the role of climate change in species extinction. Through analysis of oxygen isotopes contained in tree rings it is possible to reconstruct detailed changes in annual temperature and rainfall over several millennia. Because of this, for many years the NSF Climate Dynamics Program supported the Arizona Tree Ring Laboratory and the development of a master chronology. Secondly this project is extremely important because the Arizona prototype, if developed would serve as model for other tree ring laboratories both in the US and abroad. Although the challenge is significant, the need for a computer assisted system is evident. Dendrochronology was founded at the University of Arizona. The laboratory provides training for many dendrochronologists and its methodological innovations diffuse rapidly.
