Validating putatively cross-dated Callitris tree-ring chronologies using bomb-pulse radiocarbon analysis

2011 ◽  
Vol 59 (1) ◽  
pp. 7 ◽  
Author(s):  
Stuart Pearson ◽  
Quan Hua ◽  
Kathryn Allen ◽  
David M. J. S. Bowman
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Arid Zone ◽  
Isotopic Signature ◽  
Individual Tree ◽  
Seasonally Dry ◽  
Nuclear Weapons Testing ◽  
Independent Verification ◽  
Variable Precipitation ◽  
Cross Dating

Nuclear weapons testing during the 1950s generated an atmospheric pulse of the carbon isotope, 14C. Worldwide, trees growing during that period and in subsequent decades assimilated 14C-enriched CO2, leaving a distinct isotopic signature that can be used to precisely date tree rings. Thirty single-ring samples were extracted for AMS 14C analysis from cores taken from living trees of five different Callitris species [C. endlicheri (Parl.) F.M. Bailey, C. glaucophylla Joy Thomps. & L.A.S. Johnson, C. intratropica Benth., C. preissii Miq., and C. rhomboidea R.Br. ex Rich. & A. Rich] at 13 sites. The ages of individual tree rings were determined by both 14C bomb-pulse dating and cross-dating (based on 20–30 cores from the same site) in order to (1) provide independent verification of tree-ring dates, (2) detect false or missing rings from sites with otherwise good chronologies, and (3) test whether growth rings were annual for cores from sites where cross-dating was not possible. Our approach confirmed dates on chronologies from monsoon tropical sites, provided checked chronologies in subtropical and temperate sites, and improved dating control on arid-zone ring counts. It was found that Callitris are more likely to form regular annual rings when growing in seasonally dry environments than in more arid sites with highly variable precipitation patterns.

Using tree rings to assess the potential of thinning to alleviate drought stress in a dry forest of western Canada

2021 ◽  
Author(s):  
David Montwé ◽  
Audrey Standish ◽  
Miriam Isaac-Renton ◽  
Jodi Axelson
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Basal Area ◽  
Dry Forest ◽  
Tree Level ◽  
Severe Drought ◽  
Western Canada ◽  
Drought Event ◽  
Individual Tree ◽  
Potential Benefits

<p>Increasing frequency of severe drought events under climate change is a major cause for concern for millions of hectares of forested land. One practical solution to improving forest resilience may be thinning. There may be several potential benefits, chief of which is that drought tolerance could be improved in the remaining trees due to lower competition for resources and increased precipitation throughfall. By improving resilience to drought, this may increase productivity of the remaining trees while lowering risks of mortality. Such potential benefits can effectively be quantified with data from statistically-sound, long-term field experiments, and tree rings provide a suitable avenue to compare treatments. We work with an experiment that applied different levels of tree retention to mature interior Douglas fir (<em>Pseudotsuga menziesii</em> var. <em>glauca</em>) in a dry ecosystem of western Canada. The treatments were applied in the winter of 2002/2003, coinciding with the aftermath of a severe natural drought event in 2002. We used tree-rings to quantify the extent to which thinning improves recovery and resilience of treated trees as compared to non-thinned controls. Tree-ring samples as well as height and diameter data were obtained from 83 trees from 8 treatment units of the randomized experimental design. Indicators for resilience to drought were calculated based on basal area increments. Thinning substantially increased basal area increments at the individual tree level, but more importantly, led to significantly higher recovery and resilience relative to the control. The results of this tree-ring analysis suggest that thinning may be a viable silvicultural intervention to counteract effects of severe drought events and to maintain tree cover.</p>

Useful Strategies for the Development of Tropical Tree-Ring Chronologies

IAWA Journal ◽  
1999 ◽  
Vol 20 (3) ◽  
pp. 249-253 ◽  
Author(s):  
David W. Stahle
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Tropical Species ◽  
Growth Rings ◽  
Seasonally Dry ◽  
Effective Strategies ◽  
Annual Growth Rings ◽  
Individual Trees ◽  
The Tropics ◽  
Cross Dating

This paper outlines efficient strategies for the development of long, climatically sensitive tree-ring chronologies in the tropics. Effective strategies include sampling useful temperate or subtropical species that extend naturally into the tropics; sampling species in botanical families that have already provided examples useful for dendrochronology (e. g., Pinaceae, Taxodiaceae, Verbenaceae); targeting deciduous species in seasonally dry forests; and sampling species described in the literature or found in xylaria that have promising anatomical features such as ring porosity and marginal parenchyma. Dendrochronology can also be used to test the annual nature of growth banding in tropical species. The cross-dating oflong ring-width time series between individual trees and between multiple sites in a region is strong evidence that the growth rings are indeed synchronized with the annual calendar. This can be confirmed if the ring-width data are also strongly correlated with long annual or seasonalized records of climate variability. Blind cross-dating tests to identify the cutting dates of known-age timbers can provide a final proof that a species produces reliable annual growth rings.

scholarly journals Large scale climate signals of a European oxygen isotope network from tree-rings – predominantly caused by ENSO teleconnections?

2020 ◽  
Author(s):  
Daniel F. Balting ◽  
Monica Ionita ◽  
Martin Wegmann ◽  
Gerhard Helle ◽  
Gerhard H. Schleser ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
Tree Ring ◽  
Tree Rings ◽  
Large Scale ◽  
Southern Oscillation ◽  
Circulation Pattern ◽  
Isotopic Signature ◽  
Atmospheric Circulation Patterns ◽  
Climate Signals ◽  
Instrumental Records

Abstract. We investigate the annual variability of δ18O tree ring records from sites distributed all over Europe covering the last 400 years. An Empirical Orthogonal Function (EOF) analysis reveals two distinct modes of variability on the basis of the existing δ18O tree ring records. The first mode of δ18O variability is associated with anomaly patterns of the El Niño-Southern Oscillation (ENSO) and reflects a multi-seasonal climatic signal. The ENSO signal is visible for the last 130 years, but is found weak during the period 1600 to 1850 suggesting that the relationship between ENSO and the European climate may not stable over time. The second mode of δ18O variability, which captures an out-of-phase variability between northwestern and southeastern European δ18O tree ring records, is related to a regional summer atmospheric circulation pattern revealing a pronounced centre over the North Sea. Locally, the δ18O anomalies associated with this mode show the same (opposite) sign with temperature (precipitation). We infer that the investigation of large-scale atmospheric circulation patterns and related teleconnections far beyond instrumental records can be done with oxygen isotopic signature derived from tree rings. However, the European δ18Ocel tree network needs to be consolidated and updated, as well as additional research on the stationarity of reconstructed climate signals and the stationarity of teleconnections is advisable.

scholarly journals Timberline tree-ring statistics examined through chronology stripping

2012 ◽  
Vol 56 (1) ◽  
pp. 5-15
Author(s):  
Mauri Timonen ◽  
Kari Mielikäinen ◽  
Samuli Helama
Keyword(s):  
Sample Size ◽  
Tree Ring ◽  
Sample Selection ◽  
Ring Width ◽  
Tree Ring Chronology ◽  
Individual Tree ◽  
Tree Ring Data ◽  
The Individual ◽  
Climate Parameter ◽  
Cross Dating

Abstract Tree-ring data is commonly used in forest science and dendrochronology. As the collected datasets represent restricted populations of theoretical infinite sample size, an interesting question deals with the sample selection that is carried out during the fieldwork and through the data analyses. This paper considers the latter issue, by statistically examining a recently completed Scots pine dataset of timberline tree-rings from Lapland (northern Finland). Following the detrending of individual ring-width series, the composition of the data was restricted using a pre-determined criteria of linear correlativity between the individual sample series and the master chronology (Rmaster). This procedure reduced both the number of sites and the sample size (i.e. the number of individual tree-ring series) and altered the tree-ring statistics of the remaining subset of the data in a systematic fashion. It was seen that the first-order autocorrelation, mean sensitivity and standard deviation all ascended with the uplifted Rmaster criterion. Conspicuously, such filtering also reduced the correlation between the resulting tree-ring chronology and climate parameter. The results indicated that the screening of the data will alter the chronology statistics in a way that may be artificially generated, irrelative to the predetermined sample selection criteria. We remain to assume that the most fundamental selection of data is attained through the cross-dating process.

scholarly journals Large-scale climate signals of a European oxygen isotope network from tree rings

2021 ◽  
Vol 17 (3) ◽  
pp. 1005-1023
Author(s):  
Daniel F. Balting ◽  
Monica Ionita ◽  
Martin Wegmann ◽  
Gerhard Helle ◽  
Gerhard H. Schleser ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
Tree Ring ◽  
Tree Rings ◽  
Large Scale ◽  
Southern Oscillation ◽  
Circulation Pattern ◽  
Isotopic Signature ◽  
Atmospheric Circulation Patterns ◽  
The North ◽  
Instrumental Records

Abstract. We investigate the climate signature of δ18O tree-ring records from sites distributed all over Europe covering the last 400 years. An empirical orthogonal function (EOF) analysis reveals two distinct modes of variability on the basis of the existing δ18O tree-ring records. The first mode is associated with anomaly patterns projecting onto the El Niño–Southern Oscillation (ENSO) and reflects a multi-seasonal climatic signal. The ENSO link is pronounced for the last 130 years, but it is found to be weak over the period from 1600 to 1850, suggesting that the relationship between ENSO and the European climate may not be stable over time. The second mode of δ18O variability, which captures a north–south dipole in the European δ18O tree-ring records, is related to a regional summer atmospheric circulation pattern, revealing a pronounced centre over the North Sea. Locally, the δ18O anomalies associated with this mode show the same (opposite) sign with temperature (precipitation). Based on the oxygen isotopic signature derived from tree rings, we argue that the prevailing large-scale atmospheric circulation patterns and the related teleconnections can be analysed beyond instrumental records.

scholarly journals Tree-Ring Analysis of Intermediate Hawthorn (Crataegus media Bechst.) in NW Poland

Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Anna Cedro ◽  
Bernard Cedro
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Agricultural Landscape ◽  
Positive Influence ◽  
Dominant Factor ◽  
Incremental Growth ◽  
High Precipitation ◽  
Ring Analysis ◽  
Uncultivated Land ◽  
Nw Poland

Intermediate hawthorn (Crataegus × media Bechst.) is broadly distributed in Europe but very rarely examined by dendrochronologists. In NW Poland, it is one of three naturally occurring hawthorn species, growing mainly at forest margins, along roads, in mid-field woodlots, and on uncultivated land. Biocenotically, it is a very valuable species. This study aimed to determine the age of trees, tree-ring dynamics, and growth–climate relationship for intermediate hawthorn. Signature years were also determined. Samples for analysis were collected from 22 trees growing in a typical agricultural landscape in a monospecific mid-field woodlot comprised of several hundred specimens of various ages and forms (shrubs and trees). Using classic methods of dendrochronological dating, a 40-year long chronology spanning 1981–2020 was constructed. The radial growth rate of intermediate hawthorn is comparable to other tree species forming stands in NW Poland and equals 2.41 mm/year. Considerable intersubject variability is noted, from 1.48 to 4.44 mm/year. The chronology was also used for dendroclimatological analyses, including correlation and response function and signature years. Of the meteorological parameters analyzed, annual incremental growth in hawthorn is the most strongly shaped by precipitation totals from May to August of the current vegetation year: high rainfall favors the formation of wide tree-rings. Statistically significant growth–climate relationships were also obtained for winter months (December of the preceding vegetation year, January and February), for which period negative correlation and regression values are noted for air temperature and insolation. Furthermore, high precipitation, low-temperature and low insolation late in the preceding vegetation year (especially in August) make a positive influence on the condition of trees in the upcoming growing season. Signature year analysis clearly pointed to precipitation as the dominant factor in shaping tree-rings in the studied hawthorn population. As there are no dendrochronological papers concerning indigenous hawthorn species, future studies should be expanded to include diverse geographic locations and habitat conditions and should include all three species of hawthorn occurring in Poland.

scholarly journals A Tree Ring Measurement Method Based on Error Correction in Digital Image of Stem Analysis Disk

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 464
Author(s):  
Wenjie Zhang ◽  
Tianzhong Zhao ◽  
Xiaohui Su ◽  
Baoguo Wu ◽  
Zhiqiang Min ◽  
...  
Keyword(s):  
Error Correction ◽  
Tree Ring ◽  
Tree Rings ◽  
Digital Image ◽  
Regression Equation ◽  
Distortion Correction ◽  
Geometric Distortion ◽  
Stem Analysis ◽  
Correction Model ◽  
Ring Radius

Stem analysis is an essential aspect in forestry investigation and forest management, as it is a primary method to study the growth law of trees. Stem analysis requires measuring the width and number of tree rings to ensure the accurate measurement, expand applicable tree species, and reduce operation cost. This study explores the use of Open Source Computer Vision Library (Open CV) to measure the ring radius of analytic wood disk digital images, and establish a regression equation of ring radius based on image geometric distortion correction. Here, a digital camera was used to photograph the stem disks’ tree rings to obtain digital images. The images were preprocessed with Open CV to measure the disk’s annual ring radius. The error correction model based on the least-square polynomial fitting method was established for digital image geometric distortion correction. Finally, a regression equation for tree ring radius based on the error correction model was established. Through the above steps, click the intersection point between the radius line and each ring to get the pixel distance from the ring to the pith, then the size of ring radius can be calculated by the regression equation of ring radius. The study’s method was used to measure the digital image of the Chinese fir stem disk and compare it with the actual value. The results showed that the maximum error of this method was 0.15 cm, the average error was 0.04 cm, and the average detection accuracy reached 99.34%, which met the requirements for measuring the tree ring radius by stem disk analysis. This method is simple, accurate, and suitable for coniferous and broad-leaved species, which allows researchers to analyze tree ring radius measurement, and is of great significance for analyzing the tree growth process.

scholarly journals ABSOLUTE DENDROCHRONOLOGICAL SCALE FOR PINE (PINUS SYLVESTRIS L.) FROM UJŚCIE (NW POLAND), DATED USING RAPID ATMOSPHERIC 14C CHANGES

Radiocarbon ◽  
2020 ◽  
pp. 1-10
Author(s):  
Marek Krąpiec ◽  
Andrzej Rakowski ◽  
Jacek Pawlyta ◽  
Damian Wiktorowski ◽  
Monika Bolka
Keyword(s):  
High Resolution ◽  
Pinus Sylvestris ◽  
Middle Ages ◽  
Tree Ring ◽  
Tree Rings ◽  
Matching Method ◽  
Early Middle Ages ◽  
Rapid Changes ◽  
Absolute Age ◽  
Nw Poland

ABSTRACT Radiocarbon (14C) analyses are commonly used to determine the absolute age of floating tree-ring chronologies. At best, with the wiggle-matching method, a precision of 10 years could be achieved. For the early Middle Ages, this situation has been markedly improved by the discovery of rapid changes in atmospheric 14C concentrations in tree-rings dated to 774/775 and 993/994 AD. These high-resolution changes can be used to secure other floating tree-ring sequences to within 1-year accuracy. While a number of studies have used the 774 even to secure floating tree-ring sequences, the less abrupt 993 event has not been so well utilized. This study dates a floating pine chronology from Ujście in Wielkopolska (Greater Poland) (NW Poland), which covers the 10th century period and is critical for studies on the beginning of the Polish State to the calendar years 859–1085 AD using the changes in single year radiocarbon around 993/4 AD.

Drought signals inferred from ring-width and stable carbon isotope chronologies from Thuja occidentalis trees growing at their northwestern distribution limit, central Canada

2012 ◽  
Vol 42 (3) ◽  
pp. 517-531 ◽  
Author(s):  
Robert Au ◽  
Jacques C. Tardif
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Stable Carbon Isotopes ◽  
Stable Carbon Isotope ◽  
Ring Width ◽  
Ring Formation ◽  
Moisture Regime ◽  
Stable Carbon ◽  
Thuja Occidentalis ◽  
Central Canada

Stable carbon isotopes (δ13C) fixed in tree rings are dependent upon environmental conditions. Old northern white-cedar ( Thuja occidentalis L.) trees were sampled at their northwestern limit of distribution in central Canada. The objectives of the study were (i) to investigate the association between tree-ring δ13C values and radial growth in addition to the response of these variables to climate, (ii) to assess site differences between two sites varying in moisture regime, and (iii) to compare tree-ring δ13C of T. occidentalis with that of other boreal tree species growing at the northern limit of their distribution in central Canada. Over 2500 tree rings comprised of 15 T. occidentalis trees were analyzed for δ13C. Annually resolved δ13C (1650–2006) and ring-width (1542–2006) chronologies were developed. During the year of ring formation, ring width was associated with spring and early-summer conditions, whereas δ13C was more indicative of overall summer conditions. However, compared with δ13C values, ring width was more often associated with climate conditions in the year prior to ring formation. Conditions conducive to moisture stress were important for both parameters. Although ring width and δ13C corresponded to the drought intervals of the 1790s, 1840s, 1890s, 1930s, and 1960–1970, ring width may be more responsive to prolonged drought than δ13C. Tree-ring δ13C could, however, provide important information regarding physiological adaptations to drought.

scholarly journals Sampling density and date influence spatial representation of tree ring reconstructions

2020 ◽  
Author(s):  
Justin T. Maxwell ◽  
Grant L. Harley ◽  
Trevis J. Matheus ◽  
Brandon M. Strange ◽  
Kayla Van Aken ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Spatial Variability ◽  
Tree Ring ◽  
Tree Rings ◽  
Large Scale ◽  
The United States ◽  
Severe Drought ◽  
Ring Network ◽  
Tree Ring Data ◽  
The Us

Abstract. Our understanding of the natural variability of hydroclimate before the instrumental period (ca. 1900 in the United States; US) is largely dependent on tree-ring-based reconstructions. Large-scale soil moisture reconstructions from a network of tree-ring chronologies have greatly improved our understanding of the spatial and temporal variability in hydroclimate conditions, particularly extremes of both drought and pluvial (wet) events. However, certain regions within these large-scale reconstructions in the US have a sparse network of tree-ring chronologies. Further, several chronologies were collected in the 1980s and 1990s, thus our understanding of the sensitivity of radial growth to soil moisture in the US is based on a period that experienced multiple extremely severe droughts and neglects the impacts of recent, rapid global change. In this study, we expanded the tree-ring network of the Ohio River Valley in the US, a region with sparse coverage. We used a total of 72 chronologies across 15 species to examine how increasing the density of the tree-ring network influences the representation of reconstructing the Palmer Meteorological Drought Index (PMDI). Further, we tested how the sampling date influenced the reconstruction models by creating reconstructions that ended in the year 1980 and compared them to reconstructions ending in 2010 from the same chronologies. We found that increasing the density of the tree-ring network resulted in reconstructed values that better matched the spatial variability of instrumentally recorded droughts and to a lesser extent, pluvials. By sampling tree in 2010 compared to 1980, the sensitivity of tree rings to PMDI decreased in the southern portion of our region where severe drought conditions have been absent over recent decades. We emphasize the need of building a high-density tree-ring network to better represent the spatial variability of past droughts and pluvials. Further, chronologies on the International Tree-Ring Data Bank need updating regularly to better understand how the sensitivity of tree rings to climate may vary through time.

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