Dendrochronology for Extended Examination of Cultural Adaptation

In a variably arid region beginning in the eighth century AD a culture developed that was ultimately transformed four hundred years later by climate challenges and migration. The timing, rate, and tempo of historical transitions in this particular region are relevant to larger questions about socioecological sustainability and the evolution of human institutions in the face of rapid environmental and population change. A group of researchers are conducting a tree-ring dating (dendrochronology) project on relevant large wood and charcoal collections. The aim of the project is to provide a new objective timeline for past events in this region. The work is coordinated with the relevant descendent communities. Results of the study are incorporated into a planned redesign of a Monument’s visitor’s center. Another important aspect of this project is that it leverages collections amassed during a large public archaeology works. By continuing to produce new knowledge from archival material, this prior US public investment in preservation continues to create value for multiple stakeholders. The project serves as a springboard for graduate and undergraduate training in the sciences, and the research helps accelerate the development of tree-ring chronologies for arid regions, a critical data gap in earth and environmental sciences. The project provides a new high resolution, independent, chronology for the archaeological record of the region based on new tree-ring dates. It represents a major improvement compared to the existing chronology that is currently based only on the time ranges for the manufacture of ceramic vessels and imprecise radiocarbon dates. This study is possible due to the recent development of a new dendrochronology technique involving the precise calibration of sequential radiocarbon dates from individual rings. This method makes it possible to dendrochronologically date wood and charcoal in regions where it has never before been practical. The study produces new insights for the arrival of the first farmers in the area, demographic and social transformations, the historical context of public architecture, and the long term sustainability of settlements. 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.