Oak Samples Research Articles

Sapwood characteristics of Quercus robur species from the south-western part of the Pannonian Basin

We analysed sapwood characteristics in 344 pedunculate oak (Quercus robur L.) samples from the south-western part of the Pannonian Basin. The samples came from 13 sites, located in Slovenia, Croatia and Serbia. The trees had an average of 13.3 sapwood rings, with a minimum of 5 and maximum of 32. Fifteen log-log linear regression models were employed to assess the statistical relationship between sapwood and heartwood variables. The number of sapwood rings (NSW), which is usually needed in dendroarchaeological dating, is significantly related to the number of heartwood rings (NHW), heartwood width (WHW) and heartwood growth rate (GHW). Older and more slowly growing trees had a higher average number of sapwood rings. Using NHW and WHW, we employed an additional multiple regression model and calculated coefficients for NSW predictions for real-world dendroarchaeological dating from the south-western part of the Pannonian Basin.

The Impact of Dovetail Angle in Single Dovetail Joints on Diagonal Compression Strength of Corner Joints for Box-Type Furniture

Abstract This study aims to determine the impacts of dovetail angle for dovetail joints on the diagonal compression strength of box-type furniture corner joints prepared in different woods, with different dovetail angles, and with different adhesives. For this reason, after drilling joints of 75°, 78°, 81°, 84°, and 87° on Oriental beech, European oak, Scotch pine, and medium-density fiberboard (MDF) samples, a diagonal compression test was applied on corners glued with polyvinyl acetate (PVAc) and polyurethane (Desmodur-vinyl trieketonol acetate [D-VTKA]) according to the ASTM D1037 standard. The highest result for dovetail diagonal compression strength was observed in the samples of Oriental beech (0.321 N mm−2), while the lowest was found in the samples of MDF (0.154 N mm−2) for wood types. With respect to adhesives, D-VTKA yielded the best results (0.268 N mm−2), while PVAc gave the worst results (0.252 N mm−2). Regarding angle types, the best result was obtained from the samples at 84° (0.302 N mm−2) and the worst from the samples at 75° (0.207 N mm−2) for dovetail joints. For the interaction of wood type, adhesive, and dovetail angle, the highest diagonal compression strength was found in the samples of Oriental beech + 81° + D-VTKA (0.445 N mm−2), while the lowest value was observed in MDF + 78° + D-VTKA (0.128 N mm−2). In conclusion, the angles and adhesives have significant effects on the corner joints of box-type furniture.

Evaluation of degradation in chemical compounds of wood in historical buildings using FT-IR and FT-Raman vibrational spectroscopy

Vibrational spectroscopy approaches like FT-IR and FT-Raman, as analytical method, can be used to assess chemical changes in historical wood structures. In this study, wood samples of three historical buildings, in Gorgan, Iran, namely Tekie Estebar, Molla Esmaiel Mosque, and the Esmaieli Buildings were selected. Wood species was determined by their macroscopic characteristics which were hornbeam (Carpinus betulus), oak (Quercus castaneifolia), beech (Fagus orientalis), and elm (Ulmus glabra), as hardwood species, and yew (Taxus baccata) as a softwood species. Also, some samples of oak were collected from northern and southern sides of the Esmaieli Building in order to compare deterioration environmental factors.. The approximate assignment of the experimental bands was completed by comparing. For this purpose, the experimental bands with the calculated band frequencies of cellulose, hemicellulose and lignin. In addition, the reported assignment for softwood and hardwood was used to confirm the vibrational assignments. The results of spectroscopy revealed that biodegradation had occurred in all species. Comparison between the most important vibrational band frequencies related to carbohydrates and lignin in hardwood species suggested that degradation of carbohydrates was greater than lignin, which could be attributed to brown rot and hydrolysis. Reduction of chemical compounds in south oak samples was higher and could be associated with prevailing wind and UV ray in this side. In the only softwood species (yew), because of its highest exposure to frequent raining, deterioration was observed in both carbohydrates and lignin.

Impregnation of Wood with Microencapsulated Bio-Based Phase Change Materials for High Thermal Mass Engineered Wood Flooring

Wood is a porous material that can be impregnated and have enhanced properties. Two species of hardwood, red oak (Quercus rubra L.) and sugar maple (Acer saccharum Marsh.), were impregnated in a reactor with a microencapsulated phase change material. The objective was to enhance the thermal mass of wood boards used as surface layers for engineered wood flooring manufacturing. Preliminary experiments were conducted on small samples in order to define suitable impregnation parameters, based on the Bethell cycle. Thin wood boards were impregnated with a microencapsulated phase change material dispersed into distilled water. Several cycles of pressure were applied. Heating storage of the impregnated wood boards was determined using a dynamic heat flow meter apparatus method. A latent heat storage of 7.6 J/g over 3 °C was measured for impregnated red oak samples. This corresponds to a heat storage enhancement of 77.0%. Sugar maple was found to be harder to impregnate and thus his thermal enhancement was lower. Impregnated samples were observed by reflective optical microscopy. Microcapsules were found mainly in the large vessels of red oak, forming aggregates. Pull-off tests were conducted on varnished samples to assess the influence of an impregnation on varnish adhesion and no significant influence was revealed. Engineered wood flooring manufactured with impregnated boards such as characterized in this study could store solar energy and thus improve buildings energy efficiency. Although wood is a material with a low-conductivity, the thermal exchange between the PCM and the building air could be good enough as the microcapsules are positioned in the surface layer. Furthermore, flooring is an area with frequent sunrays exposure. Such high thermal mass EWF could lead to energy savings and to an enhancement of occupant’s thermal comfort. This study aimed to characterize the potential of impregnation with MPCM of two wood species in order to make high thermal mass EWF.

Color Change of Selected Wood Species Affected by Thermal Treatment and Sanding

The aim of the research was to evaluate the impact of various temperatures of thermal modification and sanding treatment on the color change of sessile oak, Norway spruce, and Red meranti. Thermal modification was carried out at various temperatures. Subsequently, one side was sanded. The measurements were recorded using a BFS 33M-GSS-F01-PU-02 color reader. A Konica Minolta CR-10 Plus colorimeter and Nikon D3200 camera were used in conjunction with the Matlab program. The assessments were conducted in the color space of CIE L* a* b*. The measured values confirmed that the decrease in lightness from natural to thermally modified wood (220 °C) was the largest for non-machined spruce samples (ΔL = 42.47) and the smallest was for sanded spruce samples (ΔL = 31.64). The relative change in sample lightness was the largest for sanded oak samples (51%). The trends of the color values a* and b* were different for individual wood species. Overall, the average color change ΔE was the lowest for the non-machined meranti species (ΔE = 33.06), and the largest for the non-machined spruce (ΔE = 43.06). Comparing the individual methodologies, it was found that all methodologies provided relevant results and can be used in practice.

Effect of Ethylene Oxide Sterilization and Accelerated Ageing on the Physical and Mechanical Properties of Beech, Oak, and Elm Wood: Part 2

The effect of ethylene oxide (EO) sterilization and/or accelerated ageing on impact bending strength (IBS), tensile strength along and across the fiber (TSALF and TSACF), ultimate flexural strength along and across the fiber (FSAL and FSAC), and splitting resistance (SR) was tested in bulk and veneer wood. The IBS was greatly increased in beech but decreased in some oak samples. The EO treatment followed by ageing caused the TSACF to increase in bulk beech and to decrease in bulk oak. The EO treatment decreased the TSALF values in bulk oak, beech, and elm veneer. However, beech veneer samples exhibited increased TSALF. The ageing of EO treated samples decreased the TSALF values for veneers (oak and beech), while both bulk samples increased. A notable decline was observed due to EO treatment of oak and beech, along with post ageing decline for oak samples in FSAC values only. The FSAL values decreased after ageing of EO treated and untreated samples (oak and beech), while a post EO treatment decline was observed in oak samples only. The SR (Rw) values decreased in EO-only treated oak wood and increased in EO treated and aged samples (oak and beech).

Effect of Ethylene Oxide Sterilization and Accelerated Ageing on the Physical and Mechanical Properties of Beech, Oak, and Elm Wood: Part 1

Effects of ethylene oxide (EO) treatment on library and museum furniture were investigated. Three treatments (accelerated ageing, EO treatment, and EO treatment followed by accelerated ageing) were applied to understand the effects on physical and mechanical properties of the common furniture woods. The Buchholz indentation test/micro-hardness (MH), color and gloss, Brinell hardness/macro-hardness (BH), and surface roughness were tested. The MH of oak and beech samples was not noticeably affected by any of the treatments, whereas elm samples showed some effects. For all types of wood, color was affected by EO treatments, but not considerably affected by ageing. Gloss significantly decreased with EO and accelerated ageing treatments for all samples. In BH measurements, ageing caused a decrease in hardness for both the control and EO treated samples, although this affect was not marked in beech samples. The EO treatment caused a decrease in hardness for beech and elm samples, but no major effect was observed in oak samples. There was a significant effect on the Ra values (arithmetic average of the absolute values of the roughness profile ordinates) in the aged groups of beech and oak samples, as well as oak samples that received both EO treatment and ageing.

Biological oxidation of sulfur compounds in artificially degraded wood

Marine and lacustrine archaeological waterlogged wood encounters serious problems after excavation due to the accumulation of sulfur and iron compounds during burial. Exposure of these compounds to oxygen results in precipitation of salts and acidification, which can lead to serious structural damage, and ultimately the loss of important cultural heritage. In this study, we evaluated the capacity of the bacterium Thiobacillus denitrificans to transform sulfur compounds commonly found in waterlogged wooden objects, to more readily extractable compounds thereby eliminating the threat of degradation. Oak samples, impregnated with a solution containing iron(II) and sulfides, were used to assess the efficiency of the bacterial treatment. The model wood samples were characterized before and after treatment using different techniques such as ESEM-EDS, micro-Raman spectroscopy, XRD and Sy-XRF mapping. Before treatment, mackinawite (FeS) and mineral sulfur (α-S8) were detected in the impregnated wood. After treatment with T. denitrificans, even though some mineral sulfur remained in the samples, the predominant phase corresponded to oxidized sulfur. This demonstrates that T. denitrificans was able to use the reduced sulfur compounds present in the wood samples as an energy source, thereby producing more soluble oxidized sulfur compounds. In addition, non-invasive techniques such as Fourier transform infrared (FTIR) spectroscopy, were carried out to assess the consequences of the biological treatment on the wood structure. No negative effect on the wood was detected after the treatment in comparison with the reference-impregnated wood. This study demonstrates the feasibility of a biotechnological procedure for the preventive extraction of sulfur species from archaeological waterlogged wood.

δ13 C values in archaeological 14 C-AMS dated charcoals: assessing mid-Holocene climate fluctuations and human response from a high-resolution isotope record (Arslantepe, Turkey).

Past climate has always influenced human adaptation to the environment. In order to reconstruct palaeoclimate fluctuations and their role in the evolution of Near Eastern societies during the mid-Holocene, high-resolution Δ13 C records from fossil wood remains at the archaeological site of Arslantepe (eastern Turkey) have been developed. After chemical treatment, δ13 C values were measured by sample combustion flow using a FLASH EA-CHNS instrument interfaced with a Delta V isotope ratio mass spectrometer via a CONFLO III. Two replicates per sample were analysed. The measurement precision was evaluated by propagating variations of the δ13 C values of samples and V-PDB standards, whereas the accuracy was checked by a quality control sample. To account for changes in atmospheric CO2 , Δ13 C values were calculated. In addition, 14 C/12 C ratios were measured by means of ann AMS system (3 MV tandem accelerator). Mean Δ13 C curves of deciduous Quercus and Juniperus from archaeological levels between 4700 and 2000 BC (Arslantepe periods VIII-VI D) were produced, where the isotope values were ordered by the available RC ages. Interspecific variations of evergreen vs deciduous plants were postulated for the juniper Δ13 C values being higher than 3‰. The seasonal rainfall amount was recorded by the juniper remains, while the water table levels were obtained from the oak samples. The local climate experienced times of enhanced/reduced precipitation in concert with regional trends. Anomalies in the air mass circulation from the Mediterranean basin also produced oscillations of rainfall amount. In such a frame the Rapid Climate Change dry events had a consistent signature in the Arslantepe Δ13 C record, thus potentially contributing to social or organisational changes at the site.

Oak Kernels—Volatile Constituents and Coffee-Like Beverages

Modern consumers are much aware of potential health benefits of food and food ingredients. The food industry has been constrained to develop new products with improved sensory, nutritive and functional characteristics. In this work a potential use of English (Quercus robur) and Turkish oak (Quercus cerris) kernels as functional food components was estimated. Volatiles from native and roasted kernels were isolated using continuous hydro distillation with CH2Cl2 and analyzed with GC/MS. Coffee-like beverages were prepared from roasted kernels of both species and a sensory assessment was conducted. In the native samples the main compounds were beta-eudesmol and palmitic acid (39.9 and 24.9%, respectively) in Q. robur, and palmitic acid (53.8%) in Q. cerris. In the roasted samples the main compounds were furans: furfural (51.7 and 60.6%) and 5-methyl-furfural (8.6 and 9.4%, respectively). Coffee-like beverages from roasted oak samples were evaluated for sensory properties gaining high scores for appearance, with satisfying taste and fullness. The presented results, along with previous findings on substantial antioxidant and antiradical activities of English and Turkish Oak kernels, draw attention to these easy available, cheap, but neglected native raw materials as valuable functional food components. Further investigations on this matter are warranted.

Impact of thermal modification on color and chemical changes of spruce and oak wood

Thermal modification of wood is an environment-friendly alternative method for improving several properties of wood without the use of chemicals. This paper deals with the examination of color and chemical changes in spruce (Picea abies L.) and oak wood (Quercus robur F.) that occur due to thermal treatment. The thermal modification was performed at 160, 180, and 210 °C according to thermowood process. The color changes were measured by the spectrophotometer and described in the L*a*b* color system. Chemical changes were examined by wet chemistry methods, infrared spectroscopy and liquid chromatography. During the experiment, oak samples showed smaller color changes than spruce samples at all temperature values. During thermal modification, the content of cellulose, lignin, and extractives increases; however, the hemicellulose content drops by 58.85% (oak) and by 37.40% (spruce). In addition to deacetylation, new carbonyl and carboxyl groups are formed as a result of oxidation. Bonds in lignin (mainly β-O-4) and methoxyl groups are cleaved, and lignin is condensed at higher temperatures.

Orthotropic creep in polyethylene glycol impregnated archaeological oak from the Vasa ship

Creep in archaeological oak samples and planks from the Vasa ship impregnated with polyethylene glycol (PEG) has been studied in museum-like climate. Creep studies of duration up to three years have been performed in nearly constant relative humidity and temperature of the controlled museum climate. Cubic samples were subjected to compressive creep tests in all orthotropic directions. Additionally, the creep behaviour of planks with and without PEG and of recent oak was tested in four-point bending. The experimental results have been summarised and also compared with reference results from recent oak wood. The effect of variable ambient conditions on creep and mass changes is discussed. The experimental results of creep in the longitudinal direction showed deformations even for the low stresses. There is relatively much more scatter in creep behaviour, and not all samples showed linear viscoelastic response. The creep in radial and tangential directions of the cubes and the plank samples showed a strong dependency on the ambient conditions. Some samples showed expansion for decreasing moisture content, possibly caused by the thermal expansion of the PEG component. For the planks, increasing creep deformation was observed induced by changing ambient conditions. Such behaviour may be related to e.g. oscillations in ambient conditions and presence of PEG in the wood cell wall and cell lumen. The behaviour of PEG archaeological wood depends on the level of deterioration that occurred over centuries. However, although the findings presented here apply to this specific case, they provide a unique view on such wood.

A Dráva durvaszemcsés folyóvízi üledékéből előkerült szubfosszilis uszadékfák dendrokronológiai és faanatómiai vizsgálata

This paper presents preliminary results of dendro-chronological analyses of the first occurrence of subfossil tree trunks from drava alluvial sediments. Driftwood logs were found at an outer bend of the Drava river near the village of Babócsa. The site is covered by >6 m fluvial sand and gravel. Trunks are arranged horizontally, roughly in the same bed, between massive gravel and sand layers.. Fourteen samples had been collected within a hundred metre long outcrop, ar-ranged in three distinct sets.. half of the samples are oak (Quercus roburl., n=7), fewer samples belonged to beech (Fagus sylvatica, n=2), wych elm (Ulmus scabra, n=1), eu-ropean white elm (Ulmus laevis, n=2) and finally a there are one sample each of poplar (Populus spp.) and larch (Larix decidua). the samples were processed following the stan-dard dendrochronological protocol. ring width was measured to the nearest 0.01mm. despite the most likely origin of the samples is the riverbank; the oak trunks had narrow tree-ring sequences. an oak trunk of a diameter not more 20 cm con-tains more than 240 rings and two other oak samples have about 200 rings. These three long series could be crossdat-ed, forming a 249 year long chronology. The chronology built from the three synchronized records (sample codes bab002, bab003, bab007) was tested with surrounding oak master chronologies, without success. The first subfossil wood re-mains from the drava river and their loating chronology will be of help to understand changes in river dynamics and the former composition of the tree species on the floodplain.

A comparative transcriptomic approach to understanding the formation of cork

The transcriptome comparison of two oak species reveals possible candidates accounting for the exceptionally thick and pure cork oak phellem, such as those involved in secondary metabolism and phellogen activity. Cork oak, Quercus suber, differs from other Mediterranean oaks such as holm oak (Quercus ilex) by the thickness and organization of the external bark. While holm oak outer bark contains sequential periderms interspersed with dead secondary phloem (rhytidome), the cork oak outer bark only contains thick layers of phellem (cork rings) that accumulate until reaching a thickness that allows industrial uses. Here we compare the cork oak outer bark transcriptome with that of holm oak. Both transcriptomes present similitudes in their complexity, but whereas cork oak external bark is enriched with upregulated genes related to suberin, which is the main polymer responsible for the protective function of periderm, the upregulated categories of holm oak are enriched in abiotic stress and chromatin assembly. Concomitantly with the upregulation of suberin-related genes, there is also induction of regulatory and meristematic genes, whose predicted activities agree with the increased number of phellem layers found in the cork oak sample. Further transcript profiling among different cork oak tissues and conditions suggests that cork and wood share many regulatory mechanisms, probably reflecting similar ontogeny. Moreover, the analysis of transcripts accumulation during the cork growth season showed that most regulatory genes are upregulated early in the season when the cork cambium becomes active. Altogether our work provides the first transcriptome comparison between cork oak and holm oak outer bark, which unveils new regulatory candidate genes of phellem development.

Biological and topochemical studies on the resistance of excavated oak piles (Quercus sp.) from a historical bridge in Bavaria

Abstract Archaeological wood of 13 excavated oak piles from five historical bridge generations in Bavaria, dated from 1447 to 1787, was investigated by means of light microscopy (LM) and cellular UV-microspectrophotometry (UMSP) to study the ageing and natural resistance of the excavated wood. Furthermore, the mineral content of the ancient wood was determined to evaluate the impact of mineral inclusions on microbial resistance, tested using a mini block fungal test. The LM and UMSP analyses revealed well preserved cell wall structures and no significant modification of the lignin composition and distribution in predominant parts of the piles. Slight microbial decay caused by soft rot and erosion bacteria was only detectable at the outermost millimetres of individual piles. The fungal mini block tests yielded mass losses of ancient oak samples between 15% and 30%, independent of their analysed mineral content. The results provided evidence that the fungal resistance of the investigated ancient wood is mainly determined from the special soil with its high mineral content.

Short-lived juvenile effects observed in stable carbon and oxygen isotopes of UK oak trees and historic building timbers

Stable carbon (δ13C) and oxygen (δ18O) isotope ratios were measured on the latewood α-cellulose of individual oak (Quercus robur L, Q. petraea Liebl.) samples from living trees and historic building timbers. This represents the type of material available to produce long tree-ring chronologies for north-western Europe including the UK and Ireland. Results from the juvenile rings, those located closest to the pith, were compared with results from equivalent sections (representing the same calendar years) from independent master isotope chronologies that do not contain any juvenile wood, allowing any juvenile offsets and trends to be separated from those caused by environmental change. Oak timbers from archaeological sources are often relatively short (<100years). Therefore, removing the first 50 rings, as is typical for Pinus sp., would severely constrain the material available for chronology construction. The aim of this study was to determine the magnitude and duration of juvenile effects, including the detection of trends, offsets and their influence upon signal strength. The results show clearly that juvenile effects for oak from central England are very small and short-lived and that removing merely the first five rings closest to the pith is sufficient to avoid them. This result greatly increases the potential for building long and well-replicated stable isotope chronologies using archived oak samples from historic building timbers, allowing high-resolution climate reconstructions to be produced for the highly-populated regions, where oak is abundant and which are currently under-represented in regional palaeoclimate reconstructions.

Phylogenomic inferences from reference-mapped and de novo assembled short-read sequence data using RADseq sequencing of California white oaks (Quercus section Quercus).

The emergence of next generation sequencing has increased by several orders of magnitude the amount of data available for phylogenetics. Reduced representation approaches, such as restriction-sited associated DNA sequencing (RADseq), have proven useful for phylogenetic studies of non-model species at a wide range of phylogenetic depths. However, analysis of these datasets is not uniform and we know little about the potential benefits and drawbacks of de novo assembly versus assembly by mapping to a reference genome. Using RADseq data for 83 oak samples representing 16 taxa, we identified variants via three pipelines: mapping sequence reads to a recently published draft genome of Quercus lobata, and de novo assembly under two sets of locus filters. For each pipeline, we inferred the maximum likelihood phylogeny. All pipelines produced similar trees, with minor shifts in relationships within well-supported clades, despite the fact that they yielded different numbers of loci (68 000 - 111 000 loci) and different degrees of overlap with the reference genome. We conclude that both the reference-aligned and de novo assembly pipelines yield reliable results, and that advantages and disadvantages of these approaches pertain mainly to downstream uses of RADseq data, not to phylogenetic inference per se.

Precision dating of Cook’s Mill, a Civil War era structure in West Virginia

Dendroarchaeology can provide critical understanding of a structure built during key historic periods, such as the American Civil War (1861–1865), when historical documentation is likely to be sparse or incomplete. Cook’s Mill is located in Greenville, West Virginia and extensive information derived from deeds, court records, wills, and oral history places the present mill’s original construction in 1857. The American Civil War began shortly after its construction and military conflict in the area led to the burning of several key structures, one of which was an unknown mill in Greenville (formerly Centerville). Written history suggests the mill is original and survived the American Civil War, however we used dendroarchaeology to confirm its precise date of construction. We collected 46 samples from the mill and 6 cross sections from a nearby exhumed bridge for dendrochronological dating. The mill was constructed with white oak (Quercus alba) and tulip poplar (Liriodendron tulipifera) logs and the bridge samples were white oak. We visually and statistically crossdated 32 white oak samples from the mill and bridge by comparing them to a local chronology developed for this study and two regional oak chronologies from the International Tree-Ring Data Bank. Based on terminal ring attributes and cutting date years we were able to provide a suggested construction date of the spring or early summer of 1868. This date suggests Cook’s Mill was the mill burned during military conflict in the area and that the current structure was subsequently rebuilt following the conclusion of the war.

Relations of density, polyethylene glycol treatment and moisture content with stiffness properties of Vasa oak samples

Abstract Treatment with polyethylene glycol (PEG) is the preferred method for the conservation of waterlogged archaeological wooden objects. However, PEG impregnation leads to softening and increased hygroscopicity of the material. The present study compiles experimental results concerning the full elastic properties of PEG impregnated archaeological wood from the Vasa ship in relation to its basic density, PEG content (PEGC) and moisture content (MC). The results show a correlation between a more porous microstructure and high PEGC, and consequently, higher MC. The PEG and moisture contribute to the mass of the wooden object as well as to the softening of the material, which are undesired properties in a larger load-carrying wooden structure. A compromise between the improved dimensional stability and degradation of mechanical properties should therefore be considered in the conservation of wooden objects treated with PEG.

The Basque farmhouses of Zelaa and Maiz Goena: New dendrochronology-based findings about the evolution of the built heritage in the northern Iberian Peninsula

The Basque farmhouse, a characteristic building type for north-western Spain, is an architectural solution that allows the combined management of different rural activities. In addition to providing living quarters and a space for a cider press these farmhouses were designed to function as, among others, stable, barn and warehouse. They were often owned and managed by one family, with no links to ecclesiastic organizations. Architectural studies have established that these buildings first were constructed at the end of the 15th century without previous local precedent. This places their initial construction in a calm and relatively secure period, when the wars between the aristocratic lineages which had started in 1418, and which had resulted in assaults, looting and fires, had come to an end. The timing of their first occurrence has led to the interpretation that they represent a building tradition imported from the North. Dendrochronological research initially confirmed their late fifteenth-century origin. However recent restoration work in two previously undocumented farmhouses at Ezkio and Lazkao (Gipuzkoa territory) has enabled a reassessment of this interpretation. The architectural analysis of these buildings shows that their construction plans, which are quite similar, deviates from the general plan according to which the majority of Basque farmhouses were built. The newly identified model, wholly executed in wood with the exception of the roof covering, is based on the repetition of frames and bays. Together these generate the volume of the building, which is larger than the volume of other farmhouses. We collected a total of 81 oak (Quercus sp.) samples from both farmhouses and using Basque chronology ARAB9 as a reference established that these represent trees that were cut down in the spring of 1445 and in 1453 respectively. Since construction most likely took place within a few years after the trees were felled, this indicates that Basque farmhouses began to be constructed decades earlier than expected. At that time wars still raged in the Basque Country. If it is true that the political situation determined the degree of diffusion of non-indigenous architectural concepts in this region, the new findings can be interpreted as supporting the hypothesis that Basque farmhouses reflect a regionally-developed building tradition.