Dendrochronological Data Research Articles

OLD WOOD NEW LIGHT

The number of rings within a tree indicates its age, while analysis of those rings can also lead to new insights about wood and its provenance relevant to a wide variety of disciplines. We spoke to Professor Dan Hammarlund about his work as the coordinator of a research project dedicated to making dendrochronology data available to researchers.

Historical Wooden Ceilings in Waidhofen an der Ybbs, Austria

Abstract Wooden ceilings were among the earliest wooden constructions in wooden houses, and stone and brick buildings. In Austria, a special type of wooden ceiling is known as the Riemenbalkendecke. In Waidhofen, in the Ybbs region, these constructions are decorated with chip carvings, year numbers, and letters. There has been no systematic study on this type of ceiling in Austria. In this study, all houses in Waidhofen an der Ybbs built before 1900 were surveyed, and their ceiling constructions described. Riemenbalkendecken decorated with chip carvings and moldings appeared in 1465 CE and lasted for almost 300 years. The number of carved years was verified using dendrochronological dating. Different chip carving patterns were identified. The letters on ten ceilings can be attributed to the initials of the house owners at the time the ceiling was installed. None of the chip carvings can be attributed to ornaments that were common at the time. The art of the chip carvings on the wooden ceilings represents a special language of form.

New methods in dendroarchaeology: possibilities for studying charcoals from archaeological sites (the case of the Kara-Dyt II site, Republic of Tyva)

Traditionally, charcoal from archaeological sites was considered an unsuitable material for dendrochronological dating. The authors examined 23 coal samples from the Kara-Dyt II site (Republic of Tyva, Russia). An analysis of existing solutions for sample preparation of such material showed their low speed and efficiency. This article uses the approach developed by the authors, which allows for quick and high-quality sample preparation of a large number of charcoals with minimal labour costs. As a result, it was possible to construct a 138-year tree-ring chronology using archaeological charcoal. Further work in this direction will make it possible to solve the problem of constructing a long-term tree-ring chronology in the arid zone of South Siberia. This chronology provides a unique tool for determining the calendar age of wood from numerous burial mounds in Tuva and for an in-depth study of the relationship between climate and society over the past two millennia.

Geographic variation in growth and reproduction trade‐offs: Implications for future tree performance

AbstractForests play a crucial role providing ecosystem services to humans, yet many aspects of forest dynamics remain unknown. One key area is how climate change might impact reproduction of tree species. While most studies have focused on predicting tree growth, understanding how reproduction may change will be vital to forecasting future forest communities. Of particular interest is the relationship between annual growth and reproductive output, which has often been hypothesized as a trade‐off between allocating resources to growth or to reproduction. Two proposed pathways of this trade‐off, resource accumulation, that is, storage of resources over time, and resource allocation, that is, same year allocation of resources to reproduction, have been widely explored in relation to masting events. It has also been proposed that there is no internal trade‐off between the two functions, but rather there exists one or more climate variables that are intrinsically linked to both, that is, the weather hypothesis. In this study, we use 15 years of dendrochronological data and seed rain collections from forest stands at two latitudes to determine whether one or more of these strategies are taking place in two commonly occurring tree species: red maple, Acer rubrum; and sugar maple, Acer saccharum. We found evidence of a trade‐off in both species. We also found a combination of strategies was the norm, and there appeared to be evidence to also support the weather hypothesis. However, in both species, the strategy which dictated the trade‐off switched between the northern and southern regions, indicating a degree of plasticity that could be beneficial under changing environmental conditions. By identifying the ways in which growth and reproduction are connected and how these connections vary between different populations, we can gain insights into how trees allocate resources in response to changing conditions.

Integrating Dendrogeomorphology into Stress–Strain Numerical Models: An Opportunity to Monitor Slope Dynamic

Monitoring systems are recognized worldwide as fundamental tools for landslide risk management. However, monitoring can be difficult when dealing with large slopes in forested areas. In these situations, dendrogeomorphology can offer a low-cost and low-impact alternative for providing distributed information with an annual temporal resolution. The present study is a first attempt to integrate dendrometric and dendrogeomorphic data into a numerical finite difference model, in order to simulate the stress–strain behavior of the tree-slope system. By using a parametrical approach, the capability of the numerical model to effectively reproduce the tree stem anomalies (i.e., tilting angle, J-shaped feature, and internal stresses causing tree-ring growth anomalies such as eccentric growth and reaction wood) was verified, and the target parameters for the model calibration were identified based on a sensitivity analysis, which emphasized the relevance of the wood deformability; moreover, the interpretation of results allowed to point out different peculiarities (in terms of type of deformation, falling direction, and distribution of internal stresses) for different slope conditions (kinematics and depth of the failure surface) and different zones of the landslide (head scarp, main body, and toe). Afterwards, the modeling approach was applied to the Val Roncaglia landslide (Northen Italy), which involves a complex roto-translational kinematics, characterized by multiple sliding surfaces. The simulated stem anomalies showed good agreement with the ones arising from onsite dendrometric surveys, and they confirmed the conceptual model of the landslide, enabling the planning of further specific investigations. Moreover, the capability of the model in reproducing the tilting angle of trees, if correlated to their eccentricity, could provide a quite long time series (over more than 50–60 years) of the landslide reactivation and allow the use of dendrochronological data for the model calibration, thereby enhancing slope dynamic monitoring and landslide risk management.

Indicating landslide hazard from tree rings – Ecosystem service provided by an alder forest in the hengduan Mts, Sichuan, China

Landslides are destructive geomorphological processes that cause economic and social losses. This stimulates the development of new tools related to landslide hazard. Recently, trees, their growth rings and dendrochronology have become widely used in landslide studies. Thus, this study aims to explore the potential of trees in providing landslide-monitoring ecosystem services through dendrochronology. In our opinion, establishing such an idea would help promote empirical evidence on the efficiency of tree-ring-based tools to decision-makers. We use the example of a landslide in the Moxi basin, Sichuan, China and present results of dendrochronological analysis of growth eccentricity in 48 Nepalese alder (Alnus nepalensis) trees. This analysis provided data on event timing and magnitudes, average frequency and recurrence interval for reactivation of the study landslide, as well as spatial variability of landslide active. Based on dendrochronological data we were also able to determine the current slope balance and general hazard of landslide reactivation on the study slope. Our study shows that trees and dendrochronology can provide data on the activity of landslides that can complement and improve the results of standard engineering methods. Moreover, dendrochronology itself can provide the full information needed for landslide hazard assessment, monitoring and prediction.

Dating of oak timbers from Anadolu Hisarı (Anatolian Fortress), İstanbul-Türkiye

Anadolu Hisarı, or the Anatolian Fortress, is a prominent historic building located on the Anatolian side of Bosphorus, Istanbul, right across the well-known Rumeli Hisarı (the Rumeli Fortress). The fortress is known to have been built during the reign of the Ottoman Sultan, Yıldırım Bayezid, in 1395. In 2022 during the restoration of the fortress we collected a group of stem discs from six timbers stored in its garden for dendrochronological dating. The timbers were dated to 1395 after standard dendrochronological methods were applied. This result is consistent with the completion dates of the construction, 1395-1396, mentioned in historical records. The part of the walls from which the sampled timbers had been removed are from the original construction and were replaced during the recent restoration work. Our study shows that identifying the exact context of architectural wood removed during restoration of such historical buildings in Istanbul can help identify their original parts and the time of restoration activities that may have taken place in the past.

The use of computed tomography and X-ray fluorescence analysis in the research of printed book from the seventeenth century: book binding, tomographic reading of the text, dendrochronological dating, pigments analysis

This paper presents the use of X-ray computed tomography and X-ray fluorescence in the analysis and expert research of the seventeenth century printed book "Eukhologīon albo Molitoslov, ili Trebnik" from Kiev. The main purpose of the survey was to confirm whether the book binding is original or whether it is a rebinding, and whether there are any fragments of the hidden older texts. Commonly used radiography is usually not able to provide sufficient information for these purposes. On the other hand, computed tomography allows a detailed and three-dimensional documentation of the bookbinding technology and the structure of the materials used, including the wooden boards. It will be presented that all elements of the weave are clearly visible, making it possible to show that there are no internal defects in the stitching and materials. It has also been convincingly shown that there are no fragments or layers of older texts in the binding, so no further invasive intervention will be necessary regarding this aspect. The paper also demonstrates the possibility of reading the text in a closed book utilising X-ray computed tomography data; this option may be advantageous for massively damaged manuscripts. It will also be shown, that thanks to detailed tomographic imaging of the wood structure of the boards, a dendrochronological survey can be successfully carried out without invasive intervention into their outer layers. From the CT data it was also found that the pigments of the letters have significantly different densities. Therefore, as part of the survey, elemental analysis of the writing was also carried out using a portable X-ray fluorescence spectrometer to confirm and clarify this finding.

Integrating Dendrochronological and LiDAR Data to Improve Management of Pinus canariensis Forests under Different Thinning and Climatic Scenarios

Thinning focused on achieving growth and diameter management objectives has typically led to stands with reduced climate sensitivity compared to unthinned stands. We integrated dendrochronological with Airborne Laser Scanner (LiDAR) data and growth models to assess the long-term impact of thinning intensity on Canary pine (Pinus canariensis) radial growth. In 1988, 18 permanent treatment units were established in 73-year-old Canary pine plantations and three thinning treatments were applied (C–control-unthinned; 0% basal area removal; MT–moderate thinning: 10% and 15% basal area removal, and HT–heavy thinning: 46% and 45% basal area removal on the windward and leeward slopes, respectively). Dendrochronological data were measured in 2022 and expressed as basal area increment (BAI). The impact of climate on growth was examined by fitting linear regression models considering two different Representative Concentration Pathway (RCP) climate scenarios, RCP 2.6 and RCP 4.5. Finally, LiDAR data were used for standing segmentation to evaluate changes in overall growth under different climatic scenarios. The LiDAR–stand attributes differed between aspects. The BAI of the most recent 20 years (BAI20) after thinning was significantly higher for the moderate and heavy treatments on the leeward plots (F = 47.31, p < 0.001). On the windward plots, BAI decreased after moderate thinning. Considerable thinning treatments resulted in stronger changes in growth when compared to RCP climatic scenarios. From a silviculture perspective, the mapping of canopy structure and growth response to thinning under different climatic scenarios provides managers with opportunities to conduct thinning strategies for forest adaptation. Combining dendrochronological and LiDAR data at a landscape scale substantially improves the value of the separate datasets as forecasted growth response maps allow improving thinning management plans.

The palaeoclimatic potential of recent oak tree-ring width chronologies from Southwest Ukraine

Better insights into spatio-temporal climate signals are needed to understand more clearly the applicability to palaeoclimatic analysis and dendrochronological dating of the long tree-ring oak chronologies currently being compiled in Eastern Europe. This study investigates the climate sensitivity of two recent oak tree-ring width (TRW) chronologies from Transcarpathian and Ciscarpathian Ukraine and their coherence with 35 oak chronologies from Ukraine, Poland, Slovakia, Romania, and Hungary. The new Transcarpathian chronology consists of 247 TRW series of living trees from 13 sites covering the period 1836–2020, while the new Ciscarpathian chronology consists of 215 TRW series from 13 sites and spans the period 1775–2020. Despite the strong similarity between these two chronologies, their responses to climate differ significantly. Growing-season precipitation and particularly drought (three-month SPEI index) were found to be the primary drivers of oak growth on the border between the Carpathians and the northeastern Pannonian Basin. Spatial correlations of the Transcarpathian chronology show particularly high explained variability in the April-August SPEI index, roughly between 18.5–28.5°E and 45–52°N. In the Ciscarpathian, June precipitation primarily influenced oak radial growth but the spatial correlation was quite low. While the Transcarpathian TRW chronology was strongly correlated with eastern Slovakian and northwestern Romanian chronologies, the Ciscarpathian chronology revealed very low correlations with surrounding chronologies. This study indicates the great dendroarchaeological and palaeoclimatic potential of the Transcarpathian chronology and points to the need to analyse additional living trees from the Ciscarpathian region to understand the spatial variability of oak growth and its climate signal better.

Relation Between Success Rate and Sample Quantity in Dendrochronological Dating of Building Materials

ABSTRACT Optimizing sample quantity and quality improves cost-effective and less invasive dendrochronological investigations. Our study examined 3,831 trees, including 2,921 pine, 404 spruce, and 506 oak trees. Pine had a 79.2% success rate for dating, spruce 46.5%, and oak 67.8%. Success rates increased with more trees analysed, notably in the case of spruce. When 1–3 spruce trees were analysed, only 44% yielded dating, while 8 or more trees achieved a 91.6% success rate. For pine, success rates ranged from 89% to 98%, and oak achieved success rates between 64% and 100%, depending on the number of trees analysed. The number of annual rings also had a significant impact. For spruce with 31–60 rings, only 33% could be dated, while pine and oak had higher dateability percentages at 60.1% and 48.6%, respectively. With 91–120 rings, dateability improved to 87.7% for pine, 75% for spruce, and 72.6% for oak. We observed temporal variations in dated material availability, likely due to shifts in building material usage over centuries. This study enhances our understanding of factors affecting sample requirements for successful dendrochronological analysis. While specific results have local relevance, the underlying principles and challenges apply globally, encouraging meaningful discussions between clients and dendrochronologists.

The Stratigraphy and Chronology of Point of Pines Pueblo: Basic Facts that Underlie Complex Inferences Regarding Interactions Between Locals and Immigrants

Point of Pines Pueblo has long been central to discussions about ancient migrations and interactions between locals and immigrants in the U.S. Southwest. However, a lack of systematic analyses of collections from the site and a dearth of published data about them have left generations of researchers in the position of having to make assumptions about social processes that unfolded in the Point of Pines region. Here, we present the results of new analyses establishing basic facts that will eventually allow a more accurate reconstruction of social dynamics at Point of Pines Pueblo. We focus on stratigraphy, ceramics, dendrochronological data, and wall bonding/abutment information. We conclude that most of the pitstructures at the site date to the thirteenth century, the earliest above-ground architecture was built during the late 1200s, the early pueblo architecture was constructed by immigrants, and the Kayenta immigrant occupation involved considerable planning and coordinated action.

The climate in Poland (central Europe) in the first half of the last millennium, revisited

Abstract. The article presents updated knowledge on climate change in Poland (central Europe) in the first half of the last millennium (1001–1500). This knowledge is required to delimit the existence, duration, and scale of the Medieval Warm Period (MWP, also called the Medieval Climate Anomaly, MCA, here). To this end, it employs all available quantitative climate reconstructions created for Poland in the last 2 decades and four new reconstructions using three dendrochronological series and an extensive database of historical source data on weather conditions. The growth of conifers in lowland and upland Poland depends on the temperature in the cold season, especially in February and March. All available reconstructions based on dendrochronology data represent this time of the year. Summer temperatures were reconstructed using biological proxies and documentary evidence. The latter, however, is limited to the 15th century only. Winter temperature was used as the proxy for annual temperature proxies instead of the more usual use of summer temperature. The MWP occurred in Poland probably from the late 12th century to the first halves of the 14th or 15th centuries. All the analysed quantitative reconstructions suggest that the MWP in Poland was comparable to or warmer than the mean temperature in the period 1951–2000. The coldest conditions in the entire study period were noted in the first half of the 11th century (both winter and summer) and the second half of the 15th century (only winter). The greatest climate continentality occurred in the 15th century. Good agreement was found between the reconstructions of Poland's climate and many reconstructions available for Europe.

DATING THE NEWLY DISCOVERED CEILING PAINTING IN THE HOUSE OF ESTLAND’S NOBILITY IN TALLINN

In the course of renovating the Estonian Knighthood (Ritterschaft)House in the autumn of 2022, a magnificent find came to light in theceiling of a first floor room – a figural plafond painting on a canvasattached to the ceiling. This find is sensational since it adds to thenumber of rare and fragile canvas plafonds, only a few of whichsurvive in Estonia. This article demonstrates how archival researchand dendrochronology can work together hand in hand. Accordingto historical documents, this part of the Knighthood House was builtaround the year 1690, because it was described as nearly finishedin the spring of 1691. By applying dendrochronological dating, it
 was possible to ascertain that the trees that form the main woodenstructures were felled after the growing season of 1689 and wereused in construction, probably in 1690. The Üxküll family of Vigalamanor sold their newly completed town palace to the Knighthood ofEstonia in 1694 for unknown reasons. The plafond painting probablyoriginates from the period between those two dates, 1690 and 1694.Thus, the Knighthood House’s plafond ceiling is the only firmlydated painting of this kind in Estonian architecture. It originatesfrom an earlier period than most other plafond paintings in Tallinn,which are assessed using stylistic comparison as dating from theperiod after the Great Northern War, specifically from 1721 to 1760.The nearly 60 m2 plafond is certainly the largest in Estonia. The useof distemper and oil paint techniques together makes this paintingremarkable. It is also the only known plafond with more than onepainting layer from different periods. At the time of writing, thepainting has not yet been exposed to view. Its thematic subject matterand the details of its technical realisation will be revealed onlyafter its restoration. The question of the authorship of the plafondpainting also remains unanswered at this stage. The overpaintingwith Rococo ornamentation covering the original painting can becautiously associated with the name of the guild painter, GotthardHolm, who was paid for work done in the Knighthood House inthe 1760s.

New Pages in the History of Berezovo: A Dendrochronological Study

Berezov is a city with a rich history. A significant amount of wood has been preserved on the territory of the Berezovskoe gorodishe archaeological site. For its dating, the dendrochronological method was used, which makes possible to establish the time of construction of archaeological sites (wood harvesting) with an accuracy of up to a year/season. The material for dendrochronological studies carried out at the Siberian Dendrochronological Laboratory was 190 samples of archaeological wood in the form of saw cuts. Cross-dating was carried out according to the standard method. As a result of the study, dendrochronological dating of the archaeological sites of the Berezovsky settlement (Berezovo, Khanty-Mansi Autonomous Okrug) was carried out. Twenty-six buildings from nine estates were dated. The new data made it possible to correlate the buildings with the previously identified periodization stages in the city development. Also, authors were able to take part in a discussion about the time of the city's foundation, as well as to test a new method of preparing archaeological wood samples for dendrochronological analysis.

STRUCTURES OF THE ESTATE LAYOUT OF THE 14TH–FIRST HALF OF THE 16TH CENTURY IN THE MOSCOW KREMLIN BASED ON THE EXCAVATIONS IN THE GREAT GARDEN

The wooden structures that were part of the manor complexes of the 14th – the first half of the 16th century AD are the remains of above-ground structures and cellars dug into the ground. The latter were log frames placed in a pit dug for them. Most of the log frames were made of oak or young pine and spruce logs, which prevent researchers from obtaining a series of reliable dendrochronological dates. The above-ground (residential and economic) structures have survived in a worse condition, some of them perished in a fire at the end of the 15th century AD. Remains of ovens made of raw bricks are associated with residential buildings. The compact arrangement of the studied structures, the construction of cellars and ovens on the same site testifies to the stable layout of the estate space for a long time – from the 14th to the middle of the 16th century. At the end of the site functioning period, a very large cellar up to 5 m deep appeared on it, which could be related to the temporary court of Ivan III at the end of the 15th century.

Multidisciplinary approach to investigate human-forest relationships in southern French Alps: How to estimate the impact of populations on the local mountain wood stock?

This study presents a multidisciplinary approach between palaeoecology and the analysis of historical archives to reconstruct forest history subjected to long-term human activities. We focus on a case study from the southern French Alps (the Bléone Valley), for which a rich historical corpus but little palaeoenvironmental data are available. We compared and contrasted (i) pedoanthracological data obtained along an altitudinal transect (ca 400 m), (ii) dendrochronological data from historical buildings and old living trees, and (iii) historical data from written sources on forest management and land-use change. The aim of this paper is to demonstrate that the comparison between different proxy data to understand the history of mountain forest ecosystems and human-forest interactions is very challenging. We show that the spatial distribution of forest and treeline position have been impacted by human activities, mainly due to agro-sylvo-pastoral practices through the use of fire and forest cutting to maintain open pasture lands and local building purposes. Despite centuries of local agro-sylvo-pastoral activities, the forest composition has remained relatively unchanged since the Middle Ages. Our comparison of historical documents with dendrochronological data on local buildings and soil charcoal data shows that the local demands of wood cannot explain the observed large-scale changes in forest spatial continuity. Curiously, the highest demand for wood by local residents did not occur in pace with modern demographic boom (17th century), as would be expected. Thus, we suggest that supra-regional external regulations and State's control played a more important role in forest management. Royal shipbuilding industry, more lucrative economic stakes, and expanded demand for timber for construction of buildings in urban areas of the lower valleys and plains are among the external factors which impacted forest exploitation during periods when logging was prohibited.

The Date of Beverley Minster and its Role in the Development of Northern Gothic in the Late 12th and Early 13th Centuries

Drawing on close archaeological examination, a study of masons’ marks and especially new dendrochronological data, this article defends and develops Christopher Norton’s argument, published in 2009, that Gothic construction at Beverley Minster commenced soon after a well-documented fire in 1188. This dating was widely accepted until the 1860s, but since then there has been widespread consensus amongst scholars that Gothic construction at Beverley began no earlier than 1220. This radical re-dating disassociates Beverley with Lincoln Cathedral, and instead locates its design in relation to early Gothic construction at the abbeys of Fountains, Byland and Jervaulx, together with a wider group of ‘northern’ Gothic churches. New documentary and dendrochronological evidence also provide a more secure dating for Beverley’s 14th-century nave.

Potentiality of Charcoal as a Dendrochronological and Paleoclimatic Archive: Case Study of Archaeological Charcoal from Southeastern Altai, Russia

Archaeological charcoal from ancient nomad iron-smelting furnaces collected in the highland southeastern Russian Altai has great potential as a material for tree ring analysis. Dendrochronological dating was applied to 355 viable samples (>80% of the 448 collected ones), prepared using a new protocol. Individual tree ring series of 155 (~43%) samples were used to construct nine floating chronologies from 76 to 290 rings long. The archaeological and radiocarbon data on charcoal that fueled the hearths of the Kosh-Agach type bracket the floating tree ring chronologies between the second and tenth centuries AD. The results demonstrate that long tree ring “steppe” chronologies can be obtained for intermontane basins in the arid zone of Southern Siberia, using the analysis of charcoal samples. A strong climate signal imprinted in the annual growth of trees allowed for crossdating samples with relatively few rings. The revealed common climate signal for larches from different locations indicates similar paleoclimate conditions of their growth despite the strong modern southeastward aridization trend in the region, which was not so pronounced ca. 1.5 ka ago. The further matching of these chronologies to the calendar timeline will provide reference for the precise comparison of climatic conditions in the floors of intermontane basins and in the flanking mountains.

Multidisciplinary analyses on the 11th-12th century bronze doors of San Marco, Venice.

Two 11th- and 12th-century entrance doors from the Basilica di San Marco in Venice, made of different copper alloys and woods, were non-invasively examined in situ. The chemical composition of the metals, the way in which different metal parts were joined together, the tree species used to construct the supporting structures and the age of the wood are determined. A portable ED-XRF instrument and optical microscopes were used. The doors were also photographed to produce high-resolution orthophotos and 3D models. The metal parts of the doors were made of leaded tin-bronze and quaternary Cu-Sn-Zn-Pb alloys and were mounted on a wooden multi-layer structure of larch and silver fir; the dendrochronological dates of some of the larch boards are 1965, teminus post quem.