Review of Radiocarbon Data from Atmospheric and Tree Ring Samples for the Period 1945-1997 Ad

A summary of 14C data from atmospheric sampling and measurements on wood from annual tree rings for the period 1945-1997 AD is presented and evaluated. Atmospheric records are characterized by different distributions of bomb-test 14C between the Northem and Southem Hemispheres, latitude dependence, and seasonal fluctuations. Radiocarbon data from tree rings are summarised and plotted against atmospheric records from similar latitudes. In some cases, discrepancies are found. Possible reasons for this include: 1) the use of stored carbohydrate from the previous year, 2) different 14C levels in the air around subcanopy trees due to respiration of CO2, 3) regional and local effects of anthropogenic CO2 and 14C sources, 4) sampling of wood material too close to ring boundaries, and 5) insufficient pretreatment of tree ring sampies for dating. But in cases where trees were carefully selected and the sampies adequately pretreated, radiocarbon data from tree rings show excellent agreement with direct atmospheric sampling records.

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14C Measurements of Tree Rings of a Japanese Cedar During 1945 to 2000 and Core Sampling for Environmental Studies

Radiocarbon ◽

10.1017/s0033822200042909 ◽

2007 ◽

Vol 49 (2) ◽

pp. 1045-1053 ◽

Cited By ~ 7

Author(s):

H Kawamura ◽

H Kofuji ◽

S Gasa ◽

M Kamamoto ◽

N Sawafuji ◽

...

Keyword(s):

20Th Century ◽

Tree Rings ◽

Environmental Studies ◽

Japanese Cedar ◽

Nuclear Testing ◽

Local Effects ◽

Core Sampling ◽

Radiocarbon Data ◽

Marine Environmental ◽

Aomori Prefecture

Japanese cedar rings sampled from Aomori Prefecture, Japan, were measured to obtain tree-ring radiocarbon data covering a period of the latter half of the 20th century in the northernmost area of Honshu (mainland Japan), to obtain records of variation in atmospheric 14C concentration caused by past atmospheric nuclear testing, and to study any possible local effects. This work, carried out on a partial disk, was also intended to provide a reference for data obtained by core sampling of live, standing Japanese black pines as a part of marine environmental studies.

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Tracking atmospheric carbon emissions in southern Ontario, Canada using dendrochronological records

10.5194/egusphere-egu21-10031 ◽

2021 ◽

Author(s):

Michael Pisaric ◽

Carley Crann ◽

Felix Vogel

Keyword(s):

Environmental Change ◽

Tree Ring ◽

Tree Rings ◽

Fossil Fuel ◽

Cosmic Ray ◽

Proxy Data ◽

Southern Ontario ◽

Clean Air ◽

Atmospheric Sampling ◽

Instrumental Records

Records of environmental change are often temporally short, perhaps spanning a few decades.&#160; For many environmental issues impacting the world today, we have very limited observations or data concerning those changes.&#160; Therefore, we need to supplement the short observational and instrumental records of environmental change with proxy data sources.&#160; Tree-ring growth records are one type of proxy data source that can be examined at annual timescales to track changes in the environment across longer periods than afforded by relatively short observations and instrumental data records.&#160; Changes in the composition of some gases in the atmosphere, are one example of environmental change that can be elucidated using tree-ring records.&#160; Trees utilize various forms of carbon dioxide during photosynthesis, including radiocarbon (14C).&#160; Naturally, 14C in the atmosphere varies through time due to cosmic ray flux and ocean-atmosphere dynamics.&#160; The concentration of 14C also varies due to anthropogenic activities, including burning of fossil fuels, nuclear bomb testing, and the operation of nuclear power plants (NPPs).&#160; Tree rings record atmospheric 14C concentration during the growing season and are an effective tool to trace 14C in the atmosphere from a variety of sources, including NPPs.In Southern Ontario, Canada there are 15 operational CANDU reactors at three NPPs (Bruce (8), Darlington (1) and Pickering (6)).&#160; Southern Ontario is also one of the most densely populated regions of Canada and is a major source of fossil fuel derived carbon that is depleted in 14C. Monitoring of atmospheric 14C in Ontario is conducted at the&#160;Centre for Atmospheric Research Experiments, operated by Environment and Climate Change Canada (ECCC).&#160; The facility is considered a clean air site, located approximately halfway between the Bruce and Darlington NPPs.&#160;We measured the &#916;14C in tree rings from white spruce (Picea glauca) trees sampled across a west-east geographic transect between the NPPs with the aim of better understanding how the atmospheric concentration of 14C has varied locally in this region, while also attempting to pinpoint sources of 14C emissions. Data from our clean-air sites track globally derived 14C data from the &#160;Jungfraujoch clean-air atmospheric sampling site in Switzerland.&#160; Tree-ring 14Cmeasurements from our most densely populated site near the city of Toronto are depleted in 14C, reflecting fossil fuel combustion. Conversely, 14C measurements at our site nearest the Pickering and Darlington NPPs are the most enriched. Our results give insight into how tree rings record 14C and how well they compare to established atmospheric sampling techniques.&#160;

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

Forests ◽

10.3390/f12010029 ◽

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.

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

Forests ◽

10.3390/f12040464 ◽

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.

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

Radiocarbon ◽

10.1017/rdc.2020.116 ◽

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.

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

Canadian Journal of Forest Research ◽

10.1139/x2012-012 ◽

2012 ◽

Vol 42 (3) ◽

pp. 517-531 ◽

Cited By ~ 5

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.

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Sampling density and date influence spatial representation of tree ring reconstructions

10.5194/cp-2020-31 ◽

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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The significance of compression wood in restoration of the leader in Pinus sihestris L. damaged by moose (Alces alces). II. Structure of growth rings in regenerating stems in relation to juvenile wood formation

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1971.020 ◽

2015 ◽

Vol 40 (2) ◽

pp. 315-340 ◽

Cited By ~ 4

Author(s):

B. A. Molski

Keyword(s):

Tree Ring ◽

Tree Rings ◽

Compression Wood ◽

Juvenile Wood ◽

Alces Alces ◽

Wood Formation ◽

Ring Structure ◽

Growth Rings ◽

Late Wood ◽

Wood Compression

The corewood of pine ds very prone to compression wood formation, this changing the whole pattern of the tree ring structure and the siz.es of early and late wood. Compression wood always increases the formation of late wood at the expense of early wood. Tree rings with compression wood are generally wider than those without it, but there occur also tree rings wihout compression wood wider than those in which it is present, formed in the same year and in the same tree.

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A Test of “Annual Resolution” in Stalagmites Using Tree Rings

Quaternary Research ◽

10.1006/qres.2002.2354 ◽

2002 ◽

Vol 58 (2) ◽

pp. 197-199 ◽

Cited By ~ 15

Author(s):

Julio L. Betancourt ◽

Henri D. Grissino-Mayer ◽

Matthew W. Salzer ◽

Thomas W. Swetnam

Keyword(s):

New Mexico ◽

Tree Ring ◽

Tree Rings ◽

Late Holocene ◽

Ice Cores ◽

Time Interval ◽

Annual Resolution

AbstractSo-called annual banding has been identified in a number of speleothems in which the number of bands approximates the time interval between successive U-series dates. The apparent annual resolution of speleothem records, however, remains largely untested. Here we statistically compare variations in band thickness from a late Holocene stalagmite in Carlsbad Cavern, Southern New Mexico, USA, with three independent tree-ring chronologies form the same region. We found no correspondence. Although there may be various explanations for the discordance, this limited exercise suggests that banded stalagmites should be held to the same rigorous standards in chronology building and climatic inference as annually resolved tree rings, corals, and ice cores.

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

10.5194/egusphere-egu21-13182 ◽

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

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 (Pseudotsuga menziesii var. glauca) 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.

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