• The 2008 Ameridendro Awards

      Grissino-Mayer, Henri D. (Tree-Ring Society, 2009-01)
    • A 548-Year Tree-Ring Chronology Of Oak (Quercus Spp.) For Southeast Slovenia And Its Significance As a Dating Tool And Climate Archive

      Čufar, Katarina; Luis, Martín De; Zupančič, Martin; Eckstein, Dieter; University of Ljubljana, Biotechnical Faculty, Dept. of Wood Science and Technology, Rozˇna dolina, Cesta VIII/34, SI-1000 Ljubljana, Slovenia; University of Zaragoza, Dept. Geografı´a y O.T., C/Pedro Cerbuna 12, E-50009 Zaragoza, Spain; University of Hamburg, Dept. of Wood Science, Division Wood Biology, Leuschnerstr. 91, D-21031 Hamburg, Germany (Tree-Ring Society, 2008-06)
      Tree-ring series of oak, from both living trees (Quercus petraea and Q. robur) and historic timbers in southeastern Slovenia were assembled into a 548-year regional chronology spanning the period A.D. 1456–2003. It is currently the longest and the most replicated oak chronology in this part of Europe located at the transition between Mediterranean, Alpine and continental climatic influence. The chronology correlated significantly with regional and local chronologies up to 700 km away in Austria, Hungary, Serbia, Czech Republic and southern Germany. It also showed good ‘‘heteroconnection’’, i.e. agreement with chronologies of beech (Fagus sylvatica), ash (Fraxinus excelsior) and silver fir (Abies alba) in Slovenia. A preliminary dendroclimatic analysis shows that precipitation and temperature in June accounted for a high amount of variance (r250.51) in the tree-ring widths. The chronology thus contains considerable potential as a climate archive. We also present its use as a tool for the dating of wooden objects of the cultural heritage. Moreover, the chronology can be a point of reference for building tree-ring chronologies in neighboring regions.
    • A 7104-Year Annual Tree-Ring Chronology for Bristlecone Pine, Pinus Aristata, from the White Mountains, California

      Ferguson, C. W. (Tree-Ring Society, 1969-08)
      A 7104-year tree-ring chronology has been developed for bristlecone pine, Pinus aristata Englem., in the White Mountains of east-central California, U.S.A. The chronology was extended backward in time by incorporating tree-ring series from living trees up to 4600 years old, as well as from standing snags, fallen trees, large remnants, and eroded fragments. The availability of datable wood in the 9000-year range has been indicated by radiocarbon analysis. Aspects of chronology development are described. Substantiating evidence, for both age and chronology, is derived from the bristlecone pine of east-central Nevada, where a 5000-year series has been developed. Dated bristlecone pine has been used in radiocarbon studies; approximately 500 samples of dated wood have been sent to various laboratories.
    • An 800-Year Douglas Fir at Mesa Verde

      Schulman, Edmund (Tree-Ring Society, 1947-07)
    • A 435-year-long European black pine (Pinus nigra) chronology for the central-western Balkan region

      Poljanšek, S.; Ballian, D.; Nagel, T.A.; Levanič, T. (Tree-Ring Society, 2012-01)
      We describe the development of the first black pine (Pinus nigra Arnold) regional chronology for the central-western Balkan area, Bosnia and Herzegovina (BiH), based on seven site chronologies from different parts of the country. Pointer-year analysis identified a common signal (possibly climate) in the site chronologies—at least five positive (1876, 1930, 1941, 1969) and nine negative pointer years (1874, 1880, 1891, 1931, 1943, 1963, 1971, 1987, 2000) are common to all seven study sites. Site chronologies were compared using statistical parameters and visual crossdating, from which we constructed a 435-year-long tree-ring width chronology for P. nigra for BiH and compared it with existing P. nigra chronologies from Montenegro, Greece, Albania, Austria (Vienna region), and France (Corsica). The resulting statistical and visual similarity indicated that the chronology has a strong regional signal and therefore can be included in the dendrochronological network for P. nigra for the Western Balkans.
    • A method for surfacing large log cross-sections for scanning and crossdating

      Donato, D.C.; Timme, S.H. (Tree-Ring Society, 2012-07)
      We present a method for obtaining a true flat surface on cross-sections of large logs that exceed the width of many belt sanders, to aid in digital scanning and computer-aided ring-width measurement. The method uses a vertical mill that is available in most university machine shops, gradually removing thin layers of wood to achieve a surface that is planar within ca. 0.3-mm precision. We have tested the method on several sizes, shapes, and decay states of log samples and found that it performs well across these variations. Samples can then be directly sanded with medium- to fine-grit sandpaper to achieve a finished surface that lies flat on a scanner plate and shows rings and cell structure with high clarity.
    • A Method for Tree-Ring Analysis Using Diva-Gis Freeware on Scanned Core Images

      Arenas-Castro, S.; Fernández-Haeger, J.; Jordano-Barbudo, D. (Tree Ring Society, 2015-07)
      Tree-ring analysis is a basic technique of paramount importance in forest management, yet it may prove difficult and time-consuming for many slow-growth hardwood tree species. Moreover, it requires the use of specialized tools and proprietary software, which may hinder researchers working with limited budgets. We describe an innovative and inexpensive method using DIVA-GIS freeware software to analyze true color high-resolution scanned images of cores previously enhanced with ImageJ freeware (GIS-SDI), and test its accuracy against the widely-used LINTAB-TSAPWin™ and WinDENDRO™ methods. For this purpose, Abies pinsapo and Pyrus bourgaeana increment cores were processed independently using each of the three methods and the results were statistically compared. Dating results were consistent across all three methods, although identifying rings was easier and quicker to perform on the digital images. Using a modern but affordable flatbed scanner to digitize tree cores and the free DIVA-GIS software to analyze the scanned digital images proved to be an inexpensive but highly accurate and efficient approach to tree-ring analysis. Furthermore, this method greatly facilitates tree-ring analysis in species with inconspicuous rings, and enables a complete digital record of every core analyzed to be stored. Copyright © 2015 by The Tree-Ring Society.
    • A tree-ring based late summer temperature reconstruction (AD 1675–1980) for the northeastern Mediterranean

      Trouet, V. (Tree-Ring Society, 2014)
      This article presents a late summer temperature reconstruction (AD 1675–1980) for the northeastern Mediterranean (NEMED) that is based on a compilation of maximum latewood density tree-ring data from 21 high-elevation sites. This study applied a novel approach by combining individual series from all sites into one NEMED master chronology. This approach retains only the series with a strong and temporally robust common signal and it improves reconstruction length. It further improved the regional character of the reconstruction by using as a target averaged gridded instrumental temperature data from a broad NEMED region (38–45°N, 15–25°E). Cold (e.g. 1740) and warm (e.g. 1945) extreme years and decades in the reconstruction correspond to regional instrumental and reconstructed temperature records. Some extreme periods (e.g. cold 1810s) reflect European-wide or global-scale climate conditions and can be explained by volcanic and solar forcing. Other extremes are strictly regional in scope. For example, 1976 was the coldest NEMED summer over the last 350 years, but was anomalously dry and hot in northwestern Europe and is a strong manifestation of the summer North Atlantic Oscillation (sNAO). The regional NEMED summer reconstruction thus contributes to an improved understanding of regional (e.g. sNAO) vs. global-scale (i.e. external) drivers of past climate variability.
    • Accuracy in Dating - I.

      Douglass, A. E. (Tree-Ring Society, 1934-10)
    • Accuracy in Dating - II. The Presentation of Evidence

      Douglass, A. E. (Tree-Ring Society, 1935-01)
    • Acknowledgment Of Reviewers (2002-2009)

      Leavitt, Steven W.; Tree-Ring Society (Tree-Ring Society, 2010-01)
    • Addendum

      Tree-Ring Society, 2003
    • Additional Dates for Nine Mile Canyon, Northeastern Utah

      Ferguson, C. W. (Tree-Ring Society, 1949-10)
    • Additional Dates from the Allantown, Arizona, Ruins

      Miller, Carl F., Jr. (Tree-Ring Society, 1935-04)
    • Additional Dates from Tsegi

      McGregor, J. C. (Tree-Ring Society, 1936-04)
    • Advances in Dendrochronology, 1943

      Douglass, A. E. (Tree-Ring Society, 1943-01)
    • Aegean Tree-Ring Signature Years Explained

      Hughes, Malcolm K.; Kuniholm, Peter Ian; Eischeid, Jon K.; Garfin, Gregg; Griggs, Carol B.; Latini, Christine; Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ; Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology, Cornell University, Ithaca, NY; Cooperative Institute for Research in Environmental Science, University of Colorado, Boulder, CO (Tree-Ring Society, 2001)
      As a long master tree -ring chronology for the region around the Aegean approaches completion, timbers from monuments and archaeological sites as far as 2,000 km apart, and as far back as 7000 BC, are being dated. The patterns used in this dating are characterized by signature years, in which trees at the majority of the sites have smaller or broader rings than in the previous year. We show that the signature years are consistently associated with specific, persistent, circulation anomalies that control the access of precipitation- bearing systems to the region in springtime. This explains the feasibility of dating wooden objects from widely dispersed sites, and opens the possibility of reconstructing aspects of the climate in which the wood grew.
    • Age Dependence of Spiral Grain in White Oaks (Quercus Alba L.) in Southwestern Illinois

      Rauchfuss, Julia; Speer, James H.; Department of Geography, Geology, and Anthropology, Indiana State University, Terre Haute, IN 47809 (Tree-Ring Society, 2006)
      Dendrochronologists have used the presence of spiral grain as an indicator of old trees for most of the history of the field, although this relationship has been little studied. We examined cross-sections from dead trees and used a 12-mm Haglof Swedish Increment borer to collect cores from living white oak (Quercus alba L.) trees in an Eastern Deciduous Forest stand in southwestern Illinois. Spiral grain is the alignment of wood fibers to the longitudinal axis of trees and is driven by patterns of initial cambial cell division. In this study, we examine environmental factors that may affect spiral grain severity, the usefulness of non-destructive sampling methods (using the 12-mm increment borer), and the relationship between tree age and spiral grain. We tested Brazier’s method (1965) of averaging the spiral grain angle from two radii taken 180 degrees apart (i.e. one diameter in the tree) to get representative grain angles for the whole circumference of a tree at a certain height. The 12-mm increment borer did not produce consistent results in this study; therefore, the collection of cross-sections is advised for the study of spiral grain in white oaks. Brazier’s method should not be used in white oaks and should not be applied universally to all tree species. The severity of spiral grain is expressed in the xylem and may not be expressed in the bark of the tree. Left spiral grain does generally increase in white oaks with age, although this relationship is not always consistent, so a tree without severe spiral grain is not necessarily young.
    • Age of Forestdale Ruin, 1939

      Douglass, A. E. (Tree-Ring Society, 1941-07)
    • Aleppo Pine as a Medium for Tree-Ring Analysis

      Gindel, G. (Tree-Ring Society, 1944-07)