Unsolicited Proposal Submitted to the Department of Energy for Dendrochronology of Bristlecone Pine

Since 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 California. This research resulted in the establishment of a continuous tree-ring sequence of 8,680 years which proved to be a unique source of chronological data and provided precisely dated wood specimens essential to certain paleoenvironmental and geophysical investigations. Dendrochronologically dated decade samples of bristlecone pine continue to be supplied to C-14 laboratories for the calibration of the radiocarbon time scale, a development of far reaching consequences in the fields of archaeology and geology. To more fully understand the causative factors, especially the activity of the sun, a critical need exists to better define the fluctuations and trends of the C-14 curve through even stronger and earlier bristlecone pine controls. In addition, recent advances in other methods of analyzing past climatic variability –particularly techniques involving stable isotope ratios—have greatly increased the demand for wood of known age and, hence, for chronology development.During the past 18 months, the early portions of the chronology have been greatly strengthened and extended. The objective of the proposed research is to continue the extension of the bristlecone pine chronology further into the past and to strengthen it by incorporating additional dated specimens from the White Mountains and nearby areas. Prospects for a 10,000-year chronology appear increasingly possible.