• Tree-Ring Dating and the Ethnohistory of the Naval Stores Industry in Southern Georgia

      Grissino-Mayer, Henri D.; Blount, Harry C.; Miller, Alison C.; Department of Geography, The University of Tennessee, Knoxville, TN; Department of Geography, The University of South Carolina, Columbia, SC; Department of Physics, Astronomy, and Geosciences, Valdosta State University, Valdosta, GA (Tree-Ring Society, 2001)
      Since the mid-1700s, slash (Pinus elliottii Engelm.) and longleaf (Pinus palustris Mill.) pines growing in the coastal plain region of the southeastern United States were intentionally wounded ("boxed" and/or "chipped ") to induce the production of resin, which was then collected and distilled into turpentine and its derivatives (termed "gum naval stores "). Relicts from this once-dominant industry are seen throughout southern pine forests as boxed and chipped stumps or (rarely) still living trees. In this study, we dated the years of chipping on slash pines growing in two locations in Lowndes County, Georgia, to (1) better understand past forest land use patterns, and (2) raise public awareness of the ethnohistorical importance of these trees to the cultural heritage of southern Georgia. We collected cores from ten living trees with characteristic chipped surfaces ("catfaces ") from Taylor-Cowart Memorial Park (TCMP) in Valdosta, Georgia, and cross sections from ten chipped stumps in the area surrounding Lake Louise, 12 km south of Valdosta. We conclude that chipping at TCMP occurred in 1947-1948, while two chipping events occurred at Lake Louise around 1925 and between 1954-1956. Our dating was facilitated by observing periods of growth suppression, distorted and /or discolored rings, and the absence of some growth rings that may indicate possible chipping events. We recommend that these chipped stumps and living trees be preserved intact for their ethnohistorical significance, educational importance, and potential for future research.
    • Tree-Ring Evidence for Great Plains Drought

      Woodhouse, Connie A.; Brown, Peter M.; NOAA Paleoclimatology Program, NGDC, Boulder, CO | Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO; Rocky Mountain Tree-Ring Research, Fort Collins, CO (Tree-Ring Society, 2001)
      A new collection of tree-ring chronologies developed from trees and remnant material located in the western and central Great Plains makes an important contribution to the spatial coverage of the US tree- ring chronology network. Samples from 24 sites were collected from the west-central Great Plains, and to date, ten chronologies have been produced. When correlated with a set of 47 single-station PDSI records, the chronologies display relationships with regional spring and summer drought. The reconstruction of spring PDSI for eastern Colorado generated in this study suggests that the inclusion of Great Plains trees can improve the quality of Great Plains drought reconstructions. The eastern Colorado drought reconstruction explains 62% of the variance in the instrumental record and extends to 1552. This reconstruction provides information about the regional character of major droughts over the past four and a half centuries. Major eastern Colorado droughts include events in the 1580s, 1630s, 1660s, 1730s, and the 1930s. The late 16th century drought, noted as an especially severe drought in the southwestern US, appears in this reconstruction as only slightly more severe than other major droughts in this region.
    • Xylem Tracheid Development in Pinus Resinosa Seedlings in Controlled Environments

      Danzer, Shelley R.; Leavitt, Steven W.; Panyushkina, Irina P.; Mergner, Andreas; Garcia, Evelyn; Best-Svob, Valeria; Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ (Tree-Ring Society, 2001)
      Progressive tree-ring xylem cell size changes may reveal the influence of changing environment during the growing season. This study examines xylem tracheid cell growth in red pine (Pious resinosa Ait.) seedlings grown in cabinets under controlled environment, where single parameters (temperature, light, soil moisture and CO2) were varied step-wise in each chamber at ca. 30-day increments for ca. 6 months. Control and temperature treatments were replicated. Cross-sections (20 μm thick) sliced with a sliding microtome from each of four seedling stems from each cabinet were mounted on glass slides. Lumen diameters and cell-wall thickness were measured on 4 orthogonal tracheid radial files on 4 radii of each stem. Mean cell sizes were 11-17 μm among treatments and growth periods, whereas numbers of cells formed averaged 0.2-1.3 cells per day. Cell size increased throughout the experiment in most of the treatments, including one of the control treatments and those with the greatest potential to limit growth (decreasing temperature, light and soil moisture). Soil moisture was the only environmental parameter that tended to cause late declining growth, and CO, up to 500 (μmol mol⁻¹ did not appear to influence cell development. Despite a substantial range of environmental shifts in the chambers (100 μmol mol⁻¹ CO₂; 125 μEinsteins m⁻² s⁻¹ light; 8 °C temperature; 35% relative humidity; watering every day to every 5th day), the continued stem elongation and cell-size increases indicate that conditions never became significantly limiting to growth in most treatments. Although the range of environmental variability is undoubtedly much greater in most natural red pine systems, these results indicate that fairly large variations in environment during development of juvenile wood in seedlings may not leave an imprint retrievable from cell-size measurements made on the earliest rings of mature trees.