scholarly journals APPLICATIONS OF DENDROCHRONOLOGY IN NORTHWESTERN MEXICO

2017 ◽  
Vol 29 (1) ◽  
pp. 102-121 ◽  
Author(s):  
Paula Turkon ◽  
Sturt W. Manning ◽  
Carol Griggs ◽  
Marco Antonio Santos Ramírez ◽  
Ben A. Nelson ◽  
...  

Although dendrochronological methods have the potential to provide precise calendar dates, they are virtually absent in Mesoamerican archaeological research. This absence is due to several long-standing, but erroneous, assumptions: that tree rings in this region do not reflect annual growth and environmental variability, that an adequate number of samples do not exist, and that tree-ring measurements cannot be useful without modern trees to link prehispanic chronologies. In this article we present data from the sites of La Quemada and Los Pilarillos, located in the Malpaso Valley, Zacatecas, to demonstrate that suitable archaeologically derived samples of dendrochronologically useful species do exist, that the samples from these sites are measurable and cross-datable, and that the tree rings can yield precise calendar dates using a method that “wiggle-matches” radiocarbon dates on tree-ring sequences. The work demonstrates the potential of these methods to address chronological, and, in the future, climatic questions, which have so far eluded archaeological work in the region.

Radiocarbon ◽  
1993 ◽  
Vol 35 (2) ◽  
pp. 317-322 ◽  
Author(s):  
A. S. Talma ◽  
J. C. Vogel

We propose a simplified approach to the calibration of radiocarbon dates. We use splines through the tree-ring data as calibration curves, thereby eliminating a large part of the statistical scatter of the actual data points. To express the age range, we transform the ± 1 σ and ± 2 σ values of the BP age to calendar dates and interpret them as the 68% and 95% confidence intervals. This approach bypasses the conceptual problems of the transfer of individual probability values from the radiocarbon to the calendar age. We have adapted software to make this calibration possible.


Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 949-955 ◽  
Author(s):  
Toshiyuki Gandou ◽  
Hirohisa Sakurai ◽  
Wataru Katoh ◽  
Yousuke Takahashi ◽  
Syuichi Gunji ◽  
...  

We have measured the radiocarbon concentrations in single-yr tree rings of old wood by accelerated mass spectrometry (AMS) using a multicathode. The 14C concentrations of 10 single-yr tree rings were measured in 100 tree rings at intervals of 10. For each single-yr tree-ring sample, typically 80 measurements of the 14C concentrations were carried out using multicathodes. The sample standard deviations indicated that there are other fluctuations of typically 1.5%, in addition to the fluctuation of the Poisson counting statistics which is typically 3% for each measurement. The average 14C date of the tree rings was 22,130 ± 306 BP for all 624 data of single-yr tree-ring samples measured by the multicathodes. From the calibration data of Lake Suigetsu, the calendar dates of these 100 tree rings were located between 25,400 cal BP and 26,150 cal BP. The 14C dates changed between 21,979 BP and 22,272 BP, with an error of approximately 50 BP, corresponding to a precision of approximately 0.5%. There was a step with a change of approximately 144 BP for each 10 yr in the time profile.


2008 ◽  
Vol 65 (12) ◽  
pp. 2572-2578 ◽  
Author(s):  
Bryan A. Black ◽  
Darlene C. Gillespie ◽  
Shayne E. MacLellan ◽  
Claudia M. Hand

We apply the tree-ring technique of crossdating to generate highly accurate age data and evaluate error in annual growth increment (annual growth zone) counts for long-lived Pacific geoduck ( Panopea abrupta ) in the Tree Nob Islands, northern British Columbia, Canada. Crossdating is the most fundamental procedure of tree-ring analysis and is based on the tendency of environmental variability to synchronize the growth of all individuals at a given site. By crossmatching these synchronous growth “bar codes”, all growth increments can be correctly identified and assigned the correct calendar year, including the innermost year of recruitment. In this analysis, a total of 432 geoduck individuals were aged using crossdating methods as well as annual growth increment counts. The entire crossdating process was completed using visual techniques, requiring no additional equipment beyond a microscope or microprojector. When compared with crossdated ages, growth increment counts consistently underaged Pacific geoduck, particularly in the oldest individuals. These inaccuracies obscured major recruitment pulses and underestimated the rarity of strong recruitment events. To date, crossdating has been used to develop growth chronologies in a variety of marine and freshwater bivalve and fish species, but no study has demonstrated how the technique can be used to dramatically and economically improve accuracy in age data.


1974 ◽  
Vol 39 (2Part1) ◽  
pp. 350-366 ◽  
Author(s):  
P. E. Damon ◽  
C. W. Ferguson ◽  
A. Long ◽  
E. I. Wallick

AbstractExtensive radiocarbon analyses have been made of dendrochronologically dated wood. The resultant radiocarbon data are not in total agreement with the conventional solar calendar as exemplified by the tree-ring chronology. The discrepancy reaches a maximum between 4060 B.C. to 7350 B.C. when radiocarbon dates are too young by 800 to 870 yr. Using a compatible set of 549 dated samples as a working base, a calibration table has been derived for conversion of conventional radiocarbon dates to calendar dates. This conversion table covers the period of time from A.D. 1600 to 5400 B.C. Data are also given to facilitate the calculation of the accuracy of the corrected date by a simple, illustrated method.


2003 ◽  
Vol 25 (2) ◽  
pp. 165-169
Author(s):  
Paul R. J. Duffy ◽  
Olivia Lelong

Summary An archaeological excavation was carried out at Graham Street, Leith, Edinburgh by Glasgow University Archaeological Research Division (GUARD) as part of the Historic Scotland Human Remains Call-off Contract following the discovery of human remains during machine excavation of a foundation trench for a new housing development. Excavation demonstrated that the burial was that of a young adult male who had been interred in a supine position with his head orientated towards the north. Radiocarbon dates obtained from a right tibia suggest the individual died between the 15th and 17th centuries AD. Little contextual information exists in documentary or cartographic sources to supplement this scant physical evidence. Accordingly, it is difficult to further refine the context of burial, although a possible link with a historically attested siege or a plague cannot be discounted.


2003 ◽  
Vol 25 (2) ◽  
pp. 103-128
Author(s):  
Gavin Macgregor ◽  
Irene Cullen ◽  
Diane Alldritt ◽  
Michael Donnelly ◽  
Jennifer Miller ◽  
...  

Summary A programme of archaeological work was undertaken by Glasgow University Archaeological Research Division (GUARD) at West Flank Road, Drumchapel, in close proximity to the site of the prehistoric cemetery of Knappers. This paper considers the results of excavation of a range of negative features, including earlier Neolithic and Bronze Age pits and postholes. The earlier Neolithic features date to c. 3500–3000 BC and are interpreted as the partial remains of a subrectangular structure. The Bronze Age features may relate to ceremonial activities in the wider area. The significance of these remains is considered in relation to the site of Knappers and wider traditions during the fourth to second millennia BC.


2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Iriwi Louisa S. Sinon

<p><em>Study dendrochronology or tree-ring dating is defined as the study of chronological sequence of annual growth rings in trees. Teak (Tectona grandis) is one of various tree species that has been identified for the use of tree-ring studies in tropical regions. Teak is found to be suitable for dendrochronology as it is long-lived and develops defined annual growth rings. In Java, teak cans growth naturally or intensively in plantation. The two silviculture conditions will give different sensitivity on climate effect. Therefore, the effect of silviculturer will on natural teak and plantation teak in Saradan, Madiun, and East Java. As a part of the study, ten core samples from natural- growth teak were measured. The samples of growth rings is spanned from 1832 – 2004. Using the COFECHA program, the correlation of the samples (r) was found to be 0.44 point, which is satisfactory to the standard used in dendrochronology. Thus, from this study it can be concluded that natural teak could still be used in dendrochronology, although the sensitivity are not as high as plantation teak. </em></p>


Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Anna Cedro ◽  
Bernard Cedro

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.


Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 464
Author(s):  
Wenjie Zhang ◽  
Tianzhong Zhao ◽  
Xiaohui Su ◽  
Baoguo Wu ◽  
Zhiqiang Min ◽  
...  

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.


Radiocarbon ◽  
2020 ◽  
pp. 1-10
Author(s):  
Marek Krąpiec ◽  
Andrzej Rakowski ◽  
Jacek Pawlyta ◽  
Damian Wiktorowski ◽  
Monika Bolka

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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