Enhancing Dendrochronological Methods

Dendrochronology is the most precise archaeological dating method available to researchers interested in the last several thousands years. Tree-rings are accurate at the annual, and often seasonal, level of resolution and many other dating techniques are calibrated using tree-rings. Such resolution is critical when assessing hypotheses about settlement and subsistence change, and human/environment interaction. Societal benefits of this project include increasing understanding of long-term human adaptation to sociocultural and environmental variation and of increasing knowledge of past environmental variability, both of which are important for developing environmental and social policy. The Laboratory of Tree-Ring Research (LTRR) at the University of Arizona is the only institution active in all aspects of dendrochronological research. A major component of the Laboratory's research program is the analysis and dating of wood and charcoal from prehistoric and historic archaeological contexts. Thus, the LTRR has become the leading processor of archaeological tree-ring materials, the primary source of tree-ring dates in western North America and the eastern Mediterranean, and the largest repository of archaeological tree-ring samples in the world. The integration of the tree-ring dating program into the full range of dendrochronological research, teaching, and outreach activities at the Laboratory creates a unique interdisciplinary context that maximizes the scientific value of archaeological tree-ring samples and chronologies, and provides a variety of ways for different public to explore the research. The findings of the project are almost immediately integrated into University of Arizona classes. The project directly contributes to PhD dissertation and MA thesis research by students at the University of Arizona, Northern Arizona University, Washington State University, and other colleges and universities. The project contributes directly to extensive outreach activities that have reached more than 12,000 people in the last year. The LTRR tree-ring sample collections and data archives are unparalleled, easily accessed resources for archaeological, historical, and environmental research. Project results are distributed to the public through lectures, newspapers, radio, television, and the internet, improving the public's understanding of archaeological science and the scientific method. The project's primary contribution to archaeological research involves exact dating and chronology building, topics crucial to understanding past human behavior, human-environment interactions, and processes of sociocultural stability, variation, change, and evolution. The project contributes to understanding past human activities that remain outside written history, either because they occurred prior to written records or were in areas that were not recorded. Using traditional and new innovative techniques, the laboratory offers stakeholders a long-term perspective in which to understand past human land and resource use. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.