• Fire Scar Dates from Devils Tower National Monument, Wyoming

      Thompson, Marna Ares; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1983-07)
      In the fall of 1982 the Modern Studies section of the Laboratory of Tree-Ring Research agreed to analyze increment cores and cross sections of ponderosa pine (Pinus ponderosa) from Devils Tower National Monument for the purpose of providing a tree-ring chronology and a chronology of fire occurrence in Devils Tower. Three subsites were chosen and sampled in November, 1982 by Richard Guilmette of Devils Tower National Monument. A cross section was taken from one fire-scarred tree on each subsite, and increment cores were taken from ten trees on each subsite. Increment cores were collected from four additional trees on subsite DSF (vicinity of Tree 11) in January, 1983, in an attempt to strengthen the record of ring-width growth in the early 1600's. As a result of our analyses of the materials we conclude that dendrochronological dating of ponderosa pine in Devils Tower is possible, and that it can provide accurate and unique information on the nature of fire occurrence in Devils Tower.
    • Fire Scar Dates from the Pringle Falls Area of Central Oregon

      Mazany, Terry; Thompson, Marna Ares; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1983)
      In 1982 the Silviculture Laboratory located in Bend, Oregon provided the University of Arizona's Laboratory of Tree-Ring Research with nine fire-scarred ponderosa pine (Pinus ponderosa) cross sections from the Pringle Falls area in Central Oregon to assess the potential for fire history studies in that locale. The primary problem was to determine whether or not Pringle Falls tree-ring series could be dendrochronologically crossdated so that accurate calendar dates could be assigned to observed fire scars. The results of this study surpassed all initial expectations. The individual ring series did contain enough shared sensitivity for crossdating and the development of a Pringle Falls skeleton plot chronology. This chronology made possible the accurate dating of the tree -ring series and fire scars, resulting in an extraordinarily lengthy record of fire occurrence. This report describes the process of fire scar identification and presents the chronological record of dated fire scars preserved in the nine cross sections from Pringle Falls.
    • Fire Scar Dates from Walnut Canyon National Monument, Arizona

      Swetnam, Thomas W.; Wright, William E.; Caprio, Anthony C.; Brown, Peter M.; Baisan, Christopher H.; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1990-01-03)
      Eighteen samples of fire-scarred ponderosa pine (Pinus ponderosa Laws.) from Walnut Canyon National Monument (Fig. 1) were delivered to the Laboratory of Tree-Ring Research in September 1989. These partial cross section samples were prepared and dendrochronologically dated. This report contains a brief description of the methods used in this project, and a detailed listing of the dating results. Some preliminary observations of the character of fire history are offered.
    • Geohydrological Implications of Climate Change on Water Resource Development

      Stockton, Charles W.; Boggess, William R.; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1979-05)
      One of the basic assumptions in hydrology is that hydrologic time series are stationary in the sense that the probability distribution of a series can be determined from a finite sample and that it will not change with time. This assumption implies that climate which is an integral part of all hydrologic series is stationary with time. The fact is that climate is nonstationary and this non-stationarity varies from region to region. The objective of this study is to evaluate the known physical state of hydrologic processes in each of the 18 Water Resource Regions for the conterminous United States as outlined by the Water Resources Council and to speculate on the response of the system to superimposed climate variability. Four climate scenarios are evaluated encompassing all combinations of a 2 °C change in mean annual temperature with an accompanying 10 percent change in total annual precipitation. The technique used involves estimated change in mean annual runoff with respect to that of the present using empirically developed curves that relate weighted mean annual temperatures to mean annual precipitation and runoff. An evaluation of presently available models and techniques for incorporating climate variability into synthetic hydrologic traces is also discussed. Tree-ring data series are mentioned as a possible way of investigating regional climatic variability on hydrologic responses. The region-by-region evaluation of climatic change impacts indicates that a change toward a warmer and drier climate (scenario 1) would have the greatest effect on a nation-wide basis. These effects are largely adverse and the most severe impact would be in the water deficient regions west of the Mississippi River. In contrast, mostly beneficial effects would accrue from a change to cooler and wetter conditions (scenario 2). The greatest positive effects would be in the dry western regions; some negative effects would result from increased flooding on most major river systems and their tributaries, especially eastward from the Missouri and Mississippi Rivers. The effect of warmer and wetter (scenario 3) and cooler and drier (scenario 4) climatic variations on annual runoff are conjectured to be trivial in most regions. Only in the Upper Colorado River Region did scenario 3 prove to be non-trivial on a region wide basis. Our impact analysis indicates all regions would be adversely affected by a warmer and drier climatic change. In one region, the South Atlantic -Gulf, the impact is considered negligible. The adverse impacts were considered minor in the New England, Ohio, Souris-Red-Rainy, Great Basin, Pacific Northwest, and Lower Mississippi Regions. Moderate impacts are postulated for the Mid-Atlantic, Great Lakes, Tennessee, and Upper Mississippi. Major changes in the response of the water resources system are postulated for the Arkansas-White-Red, Texas Gulf, Rio Grande, Upper Colorado, Lower Colorado, California and Missouri Regions. Even under warmer and drier conditions, total runoff from the Pacific Northwest Region is greater than the present combined total annual runoff from the California, Great Basin, Lower Colorado and Upper Colorado Regions. In fact, the Pacific Northwest Region is the only region in the western United States that presently appears to have a water supply surplus. For a cooler and wetter climatic variation (scenario 2) adverse effects are predicted for some regions, although the national impact would be mostly beneficial. Adversely affected regions are the South Atlantic-Gulf, the Lower Mississippi and the Great Basin. The remaining fifteen regions would be beneficially affected, although the New England, Mid-Atlantic, Great Lakes, Souris-Red-Rainy and the Pacific Northwest Regions fall into the negligible category. An apparently beneficial impact would be felt by the Ohio, Tennessee, Upper Mississippi, Missouri, Upper Colorado, Arkansas-White-Red, Texas Gulf, Rio Grande, Lower Colorado and California Regions, although there would be increased flooding in five of these. Several regions where water is currently abundant with respect to demand, would experience only negligible or minor impacts regardless of whether warmer and drier (scenario 1) or cooler and wetter (scenario 2) climatic variations would occur. These include New England, South Atlantic-Gulf, Ohio, Souris-Red-Rainy, Great Basin and Pacific Northwest. The effects of the postulated climatic changes on the total water reserve is shown by comparing the ratios of regional total reservoir capacity to mean annual runoff for the present and for warmer and drier (scenario 1) and cooler and wetter (scenario 2) climatic variations. The results show all regions east of and including the Upper and Lower Mississippi Regions would tend to fill the existing reservoir storage in 1.2 years or less regardless of whether scenario 1 or 2 climatic variations occurred. In the west, the region most affected by either change would be the Lower Colorado River Region. Under the present climatic regime and total available storage, there is enough capacity to accommodate 12+ years of mean annual regional flow, including present level of inflow. If a warmer and drier (scenario 1) variation occurred it would require nearly 19 years reservoir capacity. In the Missouri River, the present total reservoir capacity would be quite beneficial as only a little less than two years of mean flow would be required to fill to total capacity should a cooler and wetter (scenario 2) change occur; presently a little less than three years is required. If a warmer and drier (scenario 1) change occurred, a little over eight years would be required. What are the present trends in climate? At this time, there appear to be different lines of evidence suggesting a present cooling trend over much of the Northern Hemisphere with at least one study suggesting it will continue. Some climatologists indicate that with increasing carbon-dioxide in the atmosphere, this will reverse and warming will be the dominant future trend. Analysis of individual regional runoff series do not show any indication of trends in runoff data suggesting a uniform increase in mean annual runoff. In fact, the opposite is true. In a rather restricted segment of the western southern Rocky Mountain Region, the trend is toward reduced runoff. When the overall total streamflow of the nation is considered however, there is no apparent trend in the data.
    • Giant Sequoia Fire History: A Feasibility Study

      Swetnam, Thomas W.; Baisan, Christopher H.; Brown, Peter M.; Caprio, Anthony C.; Harlan, Thomas P.; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1988-06-30)
    • Golden Trout '72

      Bard, Thomas R.; Carr, Clayton; Wright, William; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1972-06-06)
    • A Guide to Measuring Tree-Ring Widths

      Burns, James Michael; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1979-01)
      Dendrochronologists in their scientific inquiries use quantitative data, of which tree-ring widths form a major part. In order to gather the necessary quantitative tree-ring data, someone must be trained to measure the widths of the tree rings. The purpose of this paper is to explain to the person who will actually measure the tree-ring widths how the measuring process should be performed at the Laboratory of Tree-Ring Research. The following three sections describe the three phases of the measuring process. The first section deals with the preparations that must be performed before the ring widths can be measured. The second section describes the procedures for measuring the ring widths. The final section describes the checking procedure used to test the reliability of the measurements.
    • A Hydroclimatic Survey of the Great Basin: A Report on the Current Status and Future Objectives of Ongoing Research

      Stockton, Charles W.; Smith, Walter P.; Richards, Barry J.; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1983-02-21)
    • The Impact of Ozone on Sequoia Seedling Stem Structure: Implications for Seedling Survival

      Telewski, Frank W.; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 2013-10-04)
    • An Inventory of Bristlecone Pine in the Snake, Mount Moriah, Ward Mountain, and Schell Creek Divisions of the Humboldt National Forest

      Klemmedson, James O.; Beasley, R. Scott; Laboratory of Tree-Ring Research, University of Arizona; Department of Watershed Management, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 2013-10-01)
    • Jojoba Age Determination Needs Help

      Ferguson, C. W.; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1977-06)
    • Long-Term Reconstruction of Seasonal Temperature and Precipitation in the Yellowstone National Park Region Using Dendroclimatic Techniques

      Douglas, Arthur V.; Stockton, Charles W.; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1975-06)
      The goal of this investigation has been the reconstruction of past seasonal climate for the period 1750-1910 (161 years) in the Yellowstone National Park region based upon tree-ring data. Tree-ring series are useful in the reconstruction of past climate owing to the availability of large numbers of trees, the great longevity of trees, and the critical fact that the climatic information they contain is accumulated over specific years. In this project a number of tree-ring series from the region around Yellowstone National Park have been calibrated against short-term (1912-1971) seasonal temperature and precipitation data for Bozeman, Moran, Red Lodge, and Yellowstone Park. From these calibrations, long-term seasonal temperature and precipitation records have been reconstructed for each of the four stations. A major reason for these reconstructions has been the need for long-term climatic data that can be used to indicate potential variations in the climate of the park region. Knowledge of these climatic variations may facilitate estimates of natural food supplies or availability of forage in winter as related to snow depth. Previously such estimates have had to be based upon relatively short-term climatic data which undoubtedly do not encompass all possible climatic variations. With this in mind, a series of precipitation and temperature maps have been produced to indicate some of the seasonal extremes that have probably been experienced since 1750 within a given year or group of years as indicated by the tree -ring data. It is hoped that these maps will be useful to various types of researchers involved in planning within Yellowstone National Park.
    • Long-term Spatial and Temporal Drought Frequency Analysis in Western United States Utilizing Tree Rings

      Stockton, Charles W.; Boggess, W. R.; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1980-12)
    • Long-term Spatial and Temporal Drought Frequency Analysis in Western United States Utilizing Tree Rings

      Stockton, Charles W.; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1976-07)
      The main purpose of this project has been to increase our understanding of drought history of the western United States through the use of tree rings. Accordingly, we reconstructed the Palmer Drought Severity Index (PDSI) in the western United States back to A.D. 1700 from 40 tree-ring series. In addition, we studied the joint occurrence of drought in the western United States and sea surface temperatures (SST) anomalies in the eastern North Pacific. To derive a long term SST record we reconstructed SST off Baja California from tree-ring records in Mexico and the southwestern United States. From a comparison of the SST reconstruction with the PDSI reconstruction we found that anomalously cold SST in spring and early summer appears to be related to large scale spring and summer drought in western United States.
    • Long-Term Streamflow Histories of the Salt and Verde Rivers, Arizona as Reconstructed from Tree-Rings

      Smith, Lawrence P.; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1981)
    • Multivariate Techniques for Specifying Tree-Growth and Climate Relationships and for Reconstructing Anomalies in Paleoclimate

      Fritts, Harold C.; Blasing, Terence J.; Hayden, Bruce P.; Kutzbach, John E.; Laboratory of Tree-Ring Research, University of Arizona; Center for Climatic Research, University of Arizona; Department of Environmental Science, University of Virginia; Department of Environmental Science, University of Virginia (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1970-11-09)
      Ring widths from trees on certain sites reflect climatic variation. Therefore, long time series derived from replicated and precisely dated ring-width chronologies may be utilized to extend climatic records into prehistoric times. Multivariate analyses of tree -ring chronologies from western North America are used to derive response functions from which one can ascertain what climatic information each ring -width chronology contains. In addition, multivariate analyses are utilized to calibrate a large number of ring -width chronologies of diverse response functions and from widely dispersed sites with a large number of regional climatic variables. A series of transfer functions are derived which allow estimates of anomalous climatic variation from tree -ring records. Reconstructions of anomalous variation in atmospheric circulation for portions of the northern hemisphere back to A.D. 1700 are obtained by applying the transfer functions to tree -ring data for time periods when ring data are available but climatic data are not.
    • Northern Hemisphere Temperature Estimation Using Blue Group Northern Hemisphere 70-Chronology Set: High Latitude and High Altitude Sites

      LaMarche, Valmore C., Jr.; Cain, Cyra J.; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1986)
    • Past Occurrences of Winters Similar to 1976-1977 as Reconstructed from the Tree-Ring Record

      Lofgren, G. Robert; Fritts, Harold C.; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1977-10)
    • Patterns of Climatic Change Revealed Through Dendroclimatology

      Fritts, Harold C.; Lofgren, G. Robert; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1978-10)
      The objectives of this report are, first, to summarize the findings to date of the dendroclimatic work performed by our research team at the University of Arizona with respect to the broad patterns of climatic variations over North America since 1600 AD. A secondary objective, as stated in the contract, is to select set(s) of those past climatic patterns which most closely resemble or provide a perspective for conditions of climatic variability expressed as possessing a substantial degree of mobility of occurrence by the National Defense University (1978) study of climatic changes.
    • Preparation and Analysis of Tree-Ring Specimens From Washington State, USA

      Thompson, Marna Ares; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1981-11-09)
      The purpose of this project has been to produce tree-ring chronologies from increment cores of Pinus ponderosa collected from an area in Washington State south of the Trail, British Columbia copper smelter. The cores were collected by Carl Fox, now of Southern California Edison, Rosemead, California, in 1977 and delivered to the Laboratory of Tree-Ring Research in 1980. We began work on the project in July, 1981 when funding became available from the Lawrence Livermore Laboratory. According to Carl Fox, the cores were collected from seven sites, three control sites and four pollution sites. We successfully dated cores from all the control sites, but from only two of the pollution sites. We have produced five site chronologies from the dated cores. However, we suggest that because of the nature of the chronologies, the individual core and tree chronologies comprising the site chronologies may provide more meaningful information than the site chronologies for subsequent analyses of the data.