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Dendrochronology of Bristlecone PineSince Edmund Schulman’s initial interest in 1953, the Laboratory of Tree-Ring Research has conducted dendrochronological studies of bristlecone pine (Pinus longaeva D. K. Bailey, sp. Nov.) in the White Mountains of east-central California where living trees reach ages in excess of 4,000 years. The focus of this report relates to the support by the Geology and Anthropology sections in the National Science Foundation under grant EAR-8018687 for the period 1 April 1981 to 31 October 1984 with the assistance of the Department of Energy contract no. DE-AC02-81EV10680 covering the period 1 May 1981 to 31 October 1982. A summary of this research was recently published in Radiocarbon (Ferguson and Graybill 1983). In most cases various facets of the work were related to projects sponsored by all agencies. Therefore the full range of activities during that period is described herein. The primary project goals were: To extend the bristlecone pine chronology from the White Mountains of California beyond 6700 B.C. and strengthen it by incorporating additional specimens. To develop bristlecone pine chronologies in new areas for applications in archaeology, isotopic studies, and other earth sciences. To furnish dendrochronologically dated wood to researchers engaged in the study of past variations in carbon isotopes and climate.
Dendrochronology of Bristlecone Pine Prior to 4000 B.C.A 7104 -year tree -ring chronology for bristlecone pine was published in tabular form in 1969. Since then, the chronology has been improved in quality and extended in time. Twenty-one pieces of wood, representing separate trees, have been identified for the period prior to 4000 B.C. and these have made possible a chronology extension to nearly 8200 years. In this paper, the specimens are described in terms of the time range each represents and their statistical parameters relating to the quality of tree-ring record they contain. These specimens not only have extended the climatic tree-ring chronology, but also have made possible the calendar-year dating of additional samples for calibration of the radiocarbon time scale.