TY - RPRT T1 - Interim Progress Report Dendrochronology of Bristlecone Pine Y1 - 1968 A1 - Ferguson, C.W. KW - bristlecone pine KW - california KW - dendrochronology KW - NSF KW - pinus aristata KW - progress report KW - radiocarbon KW - white mountains PB - Laboratory of Tree-Ring Research CY - Tucson ER - TY - RPRT T1 - Tree-Ring Growth in High-Altitude Bristlecone Pine as Related to Meteorological Factors: Research Proposal Y1 - 1968 A1 - LaMarche, Valmore C. KW - bristlecone pine KW - cold sensitive KW - dendroclimatology KW - drought sensitive KW - high altitude KW - meteorological KW - NSF KW - pinus aristata KW - precipitation KW - temperature KW - tree ring AB -

Important climatic information may be contained in long tree-ring records from the upper treeline of mid-latitude mountains. Preliminary work and the results of related research suggest that the variation in annual ring-width series from bristlecone pine (P. aristata) at the upper treeline is related to year-to-year differences in the temperature regime, in contrast to the "drought sensitivity" of this species near the lower forest border. Therefore, the establishment of a quantitative relationship between meterological factors and tree-ring growth at the upper treeline may permit the extension of temperature records, ad would provide an additional tool for evaluating certain environmental characteristics of remote, high-mountain regions. Direct comparison of tree-ring chronologies from "drought-sensitive" conifers at the lower forest border with those from "cold-sensitive" trees at the nearby upper treeline might also lead to the separation of precipitation and temperature effects in paleoclimatic reconstruction.

The basic approach involves the empirical comparison of tree-ring chronologies with concurrent meteorological time series in a few areas in the western United States, selected for the proximity of a bristlecone pine treeline to one or more high altitude weather stations. A number of replicated tree-ring samples will be dated, measured, standardized, and evaluated to form the basic tree-ring chronologies. testing the association between the ring-widths and meteorological factors will proceed through the development of progressively refined empirical models. Consistency with available biological data will serve as a general guide in the development of a meaningful model.

PB - Laboratory of Tree-Ring Research CY - Tucson ER - TY - RPRT T1 - Continuation of Studies on the Dendrochronology of Bristlecone Pine (Pinus aristata Englem.) (Continuation of Research Grant NSF-G 19949): A Research Proposal Y1 - 1963 A1 - McGinnies, W.G. KW - bristlecone pine KW - california KW - chronology KW - colorado river basin KW - dendrochronology KW - dendroclimatology KW - extend KW - NSF KW - pinus aristata KW - white mountains AB -

The original research grant NSF-G 19949, effective October 1, 1961, for the dendrochronology of bristlecone pine has made it possible: (1) to develop a workable chronology extending back 3850 years, (2) to carry out studies of tree growth as related to environmental parameters through two field seasons, and (3) to make some statistical comparisions which indicate (a) that there is no significant difference between young and old trees in radial growth response to environmental variables, (b) that there are significant correlations between bristlecone pine and other coniferous species extending up to 1000 miles east and southeast, and (c) that there is strong evidence that bristlecone pine will provide a good basis for extending climatic interpretations to at least 2600 B.C.

The present request is for funds: (1) to complete an exact chronology made possible through the study of both living and dead material in the White Mountains of California; (2) to extend the chronology building to other key tree-ring areas in the Colorado River Basin with the aim of determining the past climatic chronology; (3) to statistically evaluate the various chronologies thus established for interrelations with climate and with other tree-ring series; (4) to continue the environmental studies and evaluations through a third growing season, 1964; (5) to determine the biological model of cause and effect and its statistical counterpart for estimating climate from these tree-ring series; and (6) to provide for the closely integrated radiocarbon analysis of tree-ring material.

The results will be used (1) to strengthen dendrochronological dating and to provide a master tree-ring chronology which can be used by climatologists, archaeologists, radiocarbon investigators, and others; (2) to strengthen and geographically extend the dendroclimatological studies of Schulman (1956), especially in the Colorado River Basin; (3) to provide, when integrated with various environmental studies now being conducted, a stronger basis for environmental interpretations, based on the difference in radial growth shown by trees that respond primarily to differences in precipitation. This information will be of great value to meteorologists, hydrologists, and others, including the Inter-Union Commission on Solar and Terrestrial Relationships.

PB - Laboratory of Tree-Ring Research CY - Tucson ER -