• Dendrochronological Potential Of Japanese Barberry (Berberis Thunbergii): A Case Study In The Black Rock Forest, New York

      Li, Jinbao; Xu, Chengyuan; Griffin, Kevin L.; Schuster, William S. F.; Tree-Ring Laboratory, Lamont-Doherty Earth Observatory, Columbia University; Marine Biology, Lamont-Doherty Earth Observatory, Columbia University; CSIRO Entomology, 120 Meiers Road, Indooroopilly, QLD 4068, Australia; Black Rock Forest Consortium, 129 Continental Road, Cornwall, NY 12518, USA (Tree-Ring Society, 2008-12)
      The deciduous forests of northeastern United States are currently experiencing an invasion of the exotic plant species Japanese barberry (Berberis thunbergii). This recent and rapid invasion leads to rising concern about its potential threats to native species as well as natural ecosystems, demanding a better understanding of its invasion mechanisms and potential responses to climate change. Unfortunately, few studies have been conducted to understand the influence of climate on the growth of B. thunbergii, largely because of the absence of long-term growth records. In this study we demonstrate growth rings of B. thunbergii are annually resolved and crossdatable. The first ring-width chronology of B. thunbergii was therefore developed using samples collected from the Black Rock Forest (BRF), New York. Climate-growth relationship analysis indicates the growth of B. thunbergii in the BRF is positively correlated with precipitation in prior October, current February and May–August, but is negatively correlated with current March precipitation. The growth of B. thunbergii is also negatively correlated with temperatures in prior winter (November–January) and current summer (June–July), but is positively correlated with current spring temperature (March–May). These dendrochronological results on B. thunbergii, together with further physiological studies, will improve our understanding on how the growth of this invasive species is affected by local climate dynamics, as well as the long-term invasion potential that is tied to its responses to climate change.
    • Disturbance History Of A Mixed Conifer Stand In Central Idaho, USA

      Arabas, Karen B.; Black, Bryan; Lentile, Leigh; Speer, Jim; Sparks, Jodi; Department of Environmental and Earth Sciences, Willamette University,; Hatfield Marine Science Center, Oregon State University; Dept. of Forestry and Geology, University of the South, 735 University Ave., Sewanee, TN 37383, USA; Dept. of Environmental and Ecological Sciences, Indiana State University; Dept. of Geography, Geology, and Anthropology, Indiana State University (Tree-Ring Society, 2008-12)
      We apply a combination of suppression and release criteria to reconstruct the disturbance history of a ponderosa pine – Douglas-fir stand in central Idaho. In this stand, disturbance, likely fire, induced growth releases in some trees, and sudden, severe suppressions in others. To characterize growth release following disturbance, we developed boundary-line release criteria for Douglas-fir and ponderosa pine. Suppression criteria were applied to identify disturbances defined as a growth reduction of more than 1.8 standard deviations sustained for a minimum of five years. To prevent confusing a true release event with growth increases associated with recovery from suppression, release events were not tallied for at least fifteen years following a suppression event. Release and suppression events were combined to create a disturbance chronology characterized by a high frequency of disturbance between 1820 and 1920. This period of disturbance likely reflects post-European settlement land uses such as grazing and logging as well as an increase in fire frequency. Fire suppression in the latter part of the 20th Century likely explains the decrease in disturbance after 1940. We believe that a combination of release as well as suppression criteria best describes the disturbance history of this stand.
    • A Theory-Driven Approach To Tree-Ring Standardization: Defining The Biological Trend From Expected Basal Area Increment

      Biondi, Franco; Qeadan, Fares; DendroLab, Department of Geography, University of Nevada; Chair of Forest Ecology, Swiss Federal Institute of Technology, Zurich, Switzerland; Department of Mathematics and Statistics, University of Nevada (Tree-Ring Society, 2008-12)
      One of the main elements of dendrochronological standardization is removing the biological trend, i.e. the progressive decline of ring width along a cross-sectional radius that is caused by the corresponding increase in stem size and tree age over time. The ‘‘conservative’’ option for removing this biological trend is to fit a modified negative exponential curve (or a straight line with slope ≤ 0) to the ring-width measurements. This method is based on the assumption that, especially for open-grown and/or shade-intolerant species, annual growth rate of mature trees fluctuates around a specific level, expressed by a constant ring width. Because this method has numerical and conceptual drawbacks, we propose an alternative approach based on the assumption that constant growth is expressed by a constant basal area increment distributed over a growing surface. From this starting point, we derive a mathematical expression for the biological trend of ring width, which can be easily calculated and used for dendrochronological standardization. The proposed C-method is compared to other standardization techniques, including Regional Curve Standardization (RCS), of tree-ring width from ponderosa pines (Pinus ponderosa Douglas ex P.Lawson & C.Lawson) located at the Gus Pearson Natural Area (GPNA) in northern Arizona, USA. Master ring-index chronologies built from ring area, RCS, and C-method reproduced stand-wide patterns of tree growth at the GPNA, whereas other standardization options, including the ‘‘conservative’’ one, failed to do so. In addition, the C-method has the advantage of calculating an expected growth curve for each tree, whereas RCS is based on applying the same growth curve to all trees. In conclusion, the C-method replaces the purely empirical ‘‘conservative’’ option with a theory based approach, which is applicable to individual ring-width measurement series, does not require fitting a growth curve using nonlinear regression, and can be rigorously tested for improving tree-ring records of environmental changes.
    • Dendrochronological Dating Of Vernacular Folk Crafts In Northern Central Japan

      Hoshino, Yasuharu; Okochi, Takayuki; Mitsutani, Takumi; Botanical Gardens, Tohoku University; National Institute for Cultural Properties Nara, Nara 630-8577, Japan (Tree-Ring Society, 2008-12)
      We dated vernacular folk crafts (traditional snow shovels) made of beech wood (Fagus crenata Bl.) in north-central Japan. A raw chronology was constructed for the folk crafts, spanning the period from 1721 to 1953 (233 years). The raw chronology was crossdated using a reference chronology in central Japan. Eventually, tree-ring dates were confidently determined for 26 out of 44 samples. The final tree-ring dates of the folk crafts ranged between 1872 and 1953. We used oral folkloric records collected in a public survey for comparison and verification of our results. The time period of use of the folk crafts was supposed to range between the late Meiji Period and the beginning of the Pacific War (World War II), and the tree-ring dates were generally consistent with the date range. However, the final tree-ring dates were after the Pacific War for two youngest samples, showing better agreement with the historical change in industry of modern Japan. The tree-ring dates demonstrate the potential to describe the historical use of the artifacts more accurately than the folkloric records. In addition, the existing site chronology of Japanese beech has been better replicated using the folk craft samples. The chronology can possibly be further extended using archaeological wood from historical buildings.
    • Multiple Dendrochronological Signals Indicate The Eruption Of Parícutin Volcano, Michoacán, Mexico

      Sheppard, Paul R.; Ort, Michael H.; Anderson, Kirk C.; Elson, Mark D.; Vázquez-Selem, Lorenzo; Clemens, Angelika W.; Little, Nicole C.; Speakman, Robert J.; Laboratory of Tree-Ring Research, University of Arizona; Departments of Environmental Sciences and Geology, Northern Arizona University; Bilby Research Center, Northern Arizona University; Desert Archaeology, Inc.; Instituto de Geografía, Universidad Nacional Autónoma de México, Ciudad Universitaria; Museum Conservation Institute, Smithsonian Institution (Tree-Ring Society, 2008-12)
      The eruption of Parícutin (1943–1952), a cinder cone volcano in Michoacán, Mexico, caused dendrochronological and dendrochemical responses that might be useful as general dating tools for eruptions. For the eruption period, pines near Parícutin have slightly suppressed ring widths plus high inter-annual variability of width. Wood anatomy changes include traumatic resin ducts and thin bands of false latewood. Dendrochemistry of tree rings shows little temporal variation in most elements, but beginning in 1943 sulfur content increased in rings of four trees and phosphorus content increased in rings of two trees. Hypotheses for increased S and P include new availability of pre-existing soil S and P and/or new input of S and P from the tephra itself. Pines at Parícutin also show suppressed ring widths for five years beginning in 1970, and had the eruption date not been known, the most likely conclusion from ring-width data alone would have been an eruption from 1970 to 1974. However, the 1970s suppression was in response to defoliation by a pine sawfly outbreak, not an eruption. For dendrochronological dating of cinder-cone eruptions, a combination of multiple characteristics (width, chemistry, and anatomy) would be more reliable than depending on any one characteristic alone.
    • Tree Establishment During Dry Spells At An Oak Savanna In Minnesota

      Ziegler, Susy Svatek; Larson, Evan R.; Rauchfuss, Julia; Elliott, Grant P.; Minnesota Dendroecology Laboratory, Department of Geography, University of Minnesota (Tree-Ring Society, 2008-06)
      Recent research has challenged the long-standing hypothesis that forests in the Upper Midwest of the United States developed during wetter periods and retreated during dry periods. We explored this debate by examining patterns of tree establishment on an oak savanna in east-central Minnesota within the context of variable moisture availability and fire suppression. We used superposed epoch analyses (SEA) to evaluate the mean moisture conditions for a 21-year window surrounding tree establishment dates. Before effective fire suppression (1809–1939), 24 of 42 trees with pith dates (62%) grew to 30-cm height during dry years (Palmer Drought Severity Index < -1), versus only 5 of 42 (12%) that established in wet years (PDSI > 1). Significantly more trees established during dry periods (negative PDSI values) than would be expected with the proportion of wet-to-dry years (x²= 10.738, df = 1, p-value = 0.001). Twenty of the complete sample of 74 trees with pith dates (27%) established during drought in the 1930s. We hypothesize that dry conditions limited plant productivity, which in turn decreased competition between grasses and tree seedlings and reduced rates of accumulation of fine fuels, enabling seedlings to grow tall enough to resist subsequent fires. We recommend SEA as a methodological approach to compare historical climate conditions with the timing of regeneration success in other regions of forest expansion.
    • Dendroarchaeology In Southwestern Nova Scotia And The Construction Of A Regional Red Spruce Chronology

      Robichaud, André; Laroque, Colin P.; Mount Allison Dendrochronology Laboratory, Department of Geography, Mount Allison University (Tree-Ring Society, 2008-06)
      Dendrochronology studies in Atlantic Canada are rare partly because old-growth forests are scarce making it difficult to establish multiple-century tree-ring chronologies. One approach to overcome this problem is to use tree-ring records found in the wood of historical structures. For our study, the Sinclair Inn in Annapolis Royal, Nova Scotia, was selected for a dendroarchaeological assessment because of its rich and complex history: it resulted from the merging of two early 18th Century houses (the Soullard and Skene houses). To date the Sinclair Inn, three other historical structures of a younger age were used to establish an annual ring record in lieu of old-growth forest data. Red spruce (Picea rubens), a dominant tree species in the Maritimes, was the most prominent wood found in the structures and allowed for the creation of a regional red spruce reference chronology extending far enough into the past to cover the supposed period of construction of the Sinclair Inn. Crossdating results indicate cutting dates of 1709 and 1710 for the Skene and Soullard houses, respectively, and 1769 for the inn itself. In the process of dating the structure, a ,200-year long regional floating red spruce chronology (1591–1789) was developed that will further help future dendrochronological investigations in the Maritimes.
    • Element Mobility In Bald Cypress Xylem

      Galicki, Stanley J.; Davidson, Gregg R.; Threlkeld, Stephen T.; Millsaps College Department of Geology, 1701 N. State St., Jackson, MS, 39210, USA; Department of Geology and Geological Engineering, Carrier 118, University of Mississippi, University, MS, 38677, USA; Department of Biology, Shoemaker 318, University of Mississippi, University, MS, 38677, USA (Tree-Ring Society, 2008-06)
      Trace element mobility in bald cypress (Taxodium distichum) was investigated for a suite of elements using cores from century-old trees from a wetland in Humphreys County, Mississippi. Element mobility was determined by comparing the dendrochemistry of decadal increments over the life span of a tree, and by comparing increments of the same age collected from the same tree during two different seasons. Variability within growth increments at the time of sampling was evaluated by comparing cores from the same tree collected at three points around the bole. Of 42 elements analyzed, eight were found above detection limits (As, Ca, K, Mg, Mn, Na, P, Zn). Clear evidence of translocation of P and Mn to the sapwood and K, Mg, and Na to the heartwood was observed. Ca and Zn were found with higher average concentrations in the sapwood, though evidence of translocation to the sapwood was equivocal. Arsenic did not vary significantly through any individual core. Variation in concentration was not found to be significant for any element with respect to year of sampling, season, location in the wetland, or position around the bole. With the exception of As, variation was significant with respect to increment age (decade) and location within the heartwood or sapwood.
    • Comparison Of Different Distance Measures For Cluster Analysis Of Tree-Ring Series

      García-González, Ignacio; Dept. de Botánica - Univ. Santiago de Compostela, Escola Politécnica Superior - Campus de Lugo, 27002 Lugo, Spain (Tree-Ring Society, 2008-06)
      Sixty individual ring-width series of oak (Quercus robur L.) from six sites in the northwestern Iberian Peninsula, ranging from 50 to 120 years, were grouped using hierarchical cluster analysis with different types of distance measures. Euclidean distances as well as other linkage distances based on statistics used to crossdate tree-ring series (Gleichläufigkeit and coefficient of correlation with its corresponding t-value) were compared. In addition, a new distance measure based on a corrected inversion of the Student’s t is proposed in the present paper, which takes into consideration the number of years used for series comparison. The Euclidean distances, commonly used in ecological analyses, inefficiently identified homogeneous units of trees based on their ring-width patterns. Among crossdating statistics, the correlation coefficient was more effective than Gleichläufigkeit, but the most satisfactory results were obtained when 1/t was used as distance measure. Finally, these methods of cluster analysis have been implemented into a computer program for future use of the dendrochronological community.
    • When Is One Core Per Tree Suffifcient To Characterize Stand Attributes? Results Of A Pinus Ponderosa Case Study

      Woodall, C. W.; USDA Forest Service, Northern Research Station, 1992 Folwell Avenue, St. Paul, MN 55108, USA (Tree-Ring Society, 2008-06)
      Increment cores are invaluable for assessing tree attributes such as inside bark diameter, radial growth, and sapwood area. However, because trees accrue growth and sapwood unevenly around their pith, tree attributes derived from one increment core may not provide sufficient precision for forest management/research activities. To assess the variability in a tree’s inside bark radius, sapwood radius, and 10-year radial growth estimated by tree cores, two increment cores at 90 degree angles were collected from ponderosa pine (Pinus ponderosa) trees in eastern Montana (n = 2,156). Paired core measurements varied substantially with 13% mean difference for inside bark radius, 19% mean difference for sapwood radius, and 23% mean difference for estimates of radial increment. Furthermore, decreasing crown ratio, decreasing diameter, and increasing site slope were all found to increase differences in estimates derived from paired cores. Whether for management or research purposes, the number of cores that should collected per tree depend on a stand’s susceptibility to reaction wood, required measurement precision, and budgetary constraints.
    • Condition Of Live Fire-Scarred Ponderosa Pine Eleven Years After Removing Partial Cross-Sections

      Heyerdahl, Emily K.; McKay, Steven J.; USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory; University of Minnesota, Department of Horticultural Science (Tree-Ring Society, 2008-06)
      Our objective is to report mortality rates for ponderosa pine trees in Oregon ten to eleven years after removing a fire-scarred partial cross-section from them, and five years after an initial survey of post-sampling mortality. We surveyed 138 live trees from which we removed fire-scarred partial crosssections in 1994/95 and 387 similarly sized, unsampled neighbor trees of the same species. These trees were from 78 plots distributed over about 5,000 ha at two sites in northeastern Oregon. The annual mortality rate for sectioned trees from 1994/95 to 2005 was 3.6% compared to 2.1% for the neighbor trees. However, many of the trees that died between 2000 and 2005 were likely killed by two prescribed fires at one of the sites. Excluding all trees in the plots burned by these fires (regardless of whether they died or not), the annual mortality rate for sectioned trees was 1.4% (identical to the rate from 1994/95 to 2000) compared to 1.0% for neighbor trees. During these fires, a greater proportion of sectioned trees died than did catfaced neighbor trees (80% versus 64%) but the difference was not significant.
    • 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.