• 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.
    • 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.
    • Using Dendrochronology To Measure Radial Growth of Defoliated Trees

      Swetnam, Thomas W.; Thompson, Marna Ares; Sutherland, Elaine Kennedy; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (U.S. Department of Agriculture, Forest Service, Cooperative State Research Service, 1985-06)