• Erosion and Deposition Produced by the Flood of December 1964 on Coffee Creek, Trinity County, California

      Stewart, John H.; LaMarche, Valmore C., Jr.; Laboratory of Tree-Ring Research, University of Arizona (United States Government Printing Office (Washington, D.C.), 1967)
    • Estimating Long-Term Statistics for Annual Precipitation for Six Regions of the United States from Tree-Ring Data

      Fritts, Harold C.; DeWitt, Emily; Gordon, Geoffrey A.; Hunt, John H.; 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; 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), 1979-12)
      Spatial anomalies of seasonal precipitation for the United States and southwestern Canada have been reconstructed from 1602 through 1961 using dendrochronologicai and multivariate techniques on 65 arid-site tree-ring chronologies from western North America. Seasonal reconstructions are averaged to obtain mean annual precipitation values for six regions of importance to the Nuclear Regulatory Commission (NRC) Nuclear Waste Management Program (NWMP). Statistics calculated from the regionally averaged annual values for 25-year and longer intervals show annual precipitation in the seventeenth through nineteenth centuries to be lower than in the twentieth century for three regions in the American Southwest and higher for one region in the Northwest and two regions in the East. The variability of precipitation generally was higher in the past three centuries than in the present century. Twenty-five-year intervals with noteworthy statistics are identified and important results are summarized and tabulated for use in the hydrologic modeling of the NWMP. Additional research is recommended to incorporate temperature and precipitation into a single hydrologic parameter.
    • Ethylene Production By Different Age Class Ponderosa and Jeffery Pine Needles as Related to Ozone Exposure and Visible Injury

      Telewski, Frank W.; Laboratory of Tree-Ring Research, University of Arizona (Springer-Verlag, 1992)
      Ethylene production by different needle age classes was characterized using a mercuric perchlorate traps in natural populations of two ponderosa pine varieties (Pinus ponderosa var. arizonica [Engelm] Shaw and var. ponderosa Dougl. ex Laws.) and Jeffery pine (Pinus leffrevi Grev. and Balf.). All ozone -exposed populations contained individuals which were symptomatic and asymptomatic with respect to visible ozone injury. Ethylene production of different needle age classes was also characterized in Pinus ponderosa var. ponderosa seedlings grown in open top ozone fumigation chambers. Older age class needles produce more ethylene than younger age class needles. Needles of both P. ponderosa var. ponderosa and P. jeffreyi exhibiting ozone injury in the field produced significantly (p >0.05) higher levels of ethylene than asymptomatic conspecifics. Seedlings exposed to highest treatment level of ozone in the fumigation study produced the highest levels of ethylene followed by fumigation with medium and low ozone concentrations and carbon filtered air. These data indicate that measurement of ethylene in conifer needles as a measure of stress needs to be calibrated for needle age class. It also suggests that the sensitivity of a tree to ozone injury may be regulated by the inherent ability of the individual to produce ethylene.
    • An Examination of the Possible Causes of Climatic Variations Revealed in Well-Verified Dendroclimatic Reconstructions for North America and the North Pacific: Final Project Report

      Fritts, H. C.; Lough, J. M.; 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), 1984-12)
    • Final Progress Report First Year - National Park Service Contract Number 14-10-0232-903

      Weekly, Ward F.; Laboratory of Tree-Ring Research, University of Arizona (2012-09-24)
    • Fire and Flood in a Canyon Woodland: The Effects of Floods and Debris Flows on the Past Fire Regime of Rhyolite Canyon, Chiricahua National Monument: Final Report

      Swetnam, Thomas; Baisan, Christopher; Caprio, Tony; McCord, Alex; Brown, Peter; Laboratory of Tree-Ring Research, University of Arizona (1990)
      Prior research in the Rhyolite Canyon area of Chiricahua National Monument (Swetnam et. al. 1989) revealed an anomalous 50 year fire-free interval between 1901 and 1851. Disruption of fire spread resulting from flooding and mass soil movement (debris flows) were postulated as potential causes of this long interval. The present study gathered additional evidence of fire and floods in the canyon system. Sampling of flood-scarred trees along stream channels successfully identified several flood events in Rhyolite canyon. Pulses of pine regeneration on debris flow deposits were associated with one of these events. However, no definitive linkage of flood events with changes in fire regime was established. Analysis of new fire scar samples combined with previous results indicated that the area affected by the change in fire regime includes the uplands between Jesse James Canyon and Rhyolite drainage. Source areas for fires prior to 1900 were not identified within the study area indicating that ignitions outside the present monument boundaries may have been important in the past. Evidence from the maximum ages of overstory conifers within Rhyolite Canyon suggests the occurrence of a major disturbance within this drainage prior to 1600.
    • Fire History in Ponderosa Pine and Mixed-Conifer Forests of the Jemez Mountains, Northern New Mexico

      Touchan, Ramzi; Swetnam, Thomas W.; 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), 1995-03-20)
      We reconstructed fire history in ponderosa pine and mixed-conifer forests across the Jemez Mountains in northern New Mexico. We collected the fire-scarred samples from nine ponderosa pine areas and four mesic mixed-conifer areas. An additional collection was obtained from a bristlecone pine stand in the Sangre de Cristo Mountains. We also reconstructed December-June precipitation from ponderosa pine tree-ring indices that were developed from four different watersheds in northern New Mexico. Prior to 1900, ponderosa pine forests were characterized by high frequency, low intensity surface fire regimes. The mixed-conifer stands sustained somewhat less frequent surface fires, along with patchy crown fires. In both ponderosa pine and mixed-conifer forests precipitation was significantly reduced in the winter-spring seasons preceding fire events. In addition, winter-spring precipitation during the third year preceding major fire years in the ponderosa pine forest was significantly increased. This study provides baseline knowledge concerning the ecological role of fire in ponderosa pine and mixed-conifer forests. This information is vital to support ongoing ecosystem management efforts in the Jemez Mountains.
    • Fire History of Rhyolite Canyon, Chiricahua National Monument

      Swetnam, Thomas W.; Baisan, Christopher H.; Brown, Peter M.; Caprio, Anthony C.; Laboratory of Tree-Ring Research, University of Arizona (Cooperative National Park Resources Studies Unit, School of Renewable Natural Resources, University of Arizona, 1989-08)
    • 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.
    • Forensic Dendrochronology

      Ferguson, C. W.; Laboratory of Tree-Ring Research, University of Arizona (1985-04-25)
    • 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)
    • Impact of Spruce Budworm on Radial Growth of Trees in Northern New Mexico

      Swetnam, Thomas W.; Laboratory of Tree-Ring Research, University of Arizona (1985-02-25)