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 (N_SW), which is usually needed in dendroarchaeological dating, is significantly related to the number of heartwood rings (N_HW), heartwood width (W_HW) and heartwood growth rate (G_HW). Older and more slowly growing trees had a higher average number of sapwood rings. Using N_HW and W_HW, we employed an additional multiple regression model and calculated coefficients for N_SW predictions for real-world dendroarchaeological dating from the south-western part of the Pannonian Basin.     

A 781-year oak tree-ring chronology for the Middle Ages archaeological dating in Maramureș (Eastern Europe)

From 1997 to the present, a sustained project in the Maramureș region in Romania was completed with the construction of a 781-year oak tree-ring chronology. A total of 395 samples from living trees and 429 from archaeological wood were analysed with dendrochronological methods. The study aimed to provide the scientific community with a new oak chronology that could be applied in dendroarchaeology, dendroclimatology and dendroecology studies and also for interpreting past socio-economic events. Furthermore, we studied the number of sapwood rings and the growth pattern for different time periods. The chronology covered the continuous period of A.D. 1236‒2016. From the 824 samples collected, we separated 271 tree-ring series into a new chronology (A.D. 1406–2016), which fulfilled all the criteria necessary to reconstruct past climate and environmental changes. The resulting new tree-ring chronology indicated robust signal series intercorrelation (r = 0.55) and an average mean sensitivity of 0.21. Based on an analysis of the sapwood, we recommend estimating a number between 8 and 32 rings to the date of final ring for 95% confidence range of mean on the for felling in the Maramureș region. Additionally, we observed that the number of sapwood rings was not correlated with altitude or oak tree species.     

A statistical model for the prediction of the number of sapwood rings in Scots pine (Pinus sylvestris L.)

Dendrochronology is a well-established dating method for wooden objects, but due to surface processing of construction timber or natural degradation the dating of historical wood often relies on a prediction of the number of missing rings based on sapwood statistics. Since Scots pine (Pinus sylvestris L.) is one of the most common tree species in north-western Europe, the absence of reliable sapwood statistics and models for the prediction of missing sapwood rings for pine samples is remarkable. We have therefore produced sapwood statistics based on data from 776 pine trees with ages from 15 to 345 years. The material consists of both living trees and historical timber, with varying growth rates, geographic settings, and from different soil types. When the whole material is considered, the average age of the trees is 103 years, and the number of sapwood rings is 54 ± 15 (1 SD), but range from 18 to 129. Trees less than 100-years in age contained 46 ± 11 (1 SD) sapwood rings and had an average tree-ring width (TRW) of 1.76 mm. With increasing age, the average TRW decreased while the number of sapwood rings increased. The average TRW of 101–200-year-old trees is 0.99 mm while the samples contained 63 ± 12 (1 SD) sapwood rings. For trees older than 201 years, the average TRW is 0.64 mm while the number of sapwood rings increased to 85 ± 16 (1 SD). The two most important factors in determining the number of sapwood rings for a given tree when only heartwood statistics are available proved to be (i) the number of heartwood rings and (ii) the average TRW of the heartwood rings. For incomplete samples, we have therefore developed a statistical model based on the sample’s heartwood rings (number and average width) to compute a prediction interval for the total number of rings. The sapwood and heartwood statistics suggest a statistical model for the number of sapwood rings with mean that increase with the number of heartwood rings. Furthermore, the average number of sapwood rings decreases with the mean width of the heartwood rings. However, the predictive power of the mean width is limited when the number of heartwood rings has already been taken into account. Thus, we suggest making predictions for the number of sapwood rings using only the number of heartwood rings. Predictions of the number of sapwood rings based on the statistical model where convincing in the case of the three different datasets that were analysed. The certainty in these predictions was such that the width of the 80% and 95% prediction intervals ranged 28–34 and 45–52 sapwood rings, respectively. Additionally, we demonstrate how make predictions when there is information about the number of remaining sapwood rings in a given sample. To make the sapwood model available, we present a free online R package for fitting our models and an online software dashboard.     

The Zurich method for sapwood estimation

We present a new predictor for the estimation of the number of missing sapwood rings in oak. It circumvents a number of problems with predictors used in traditional sapwood estimation procedures such as mean ring width or tree age. Instead, we use the mean ring width of the last 9 heartwood rings and the first sapwood ring, which mirrors the growth level during sapwood formation. We present a model to produce a 95 % prediction interval for the felling year. Our method accounts for the skewed distribution of the number of sapwood rings towards higher values.     

Pointer years in tree-ring width and earlywood-vessel area time series of Quercus robur—Relation with climate factors near its northern distribution limit

For a long time, radial growth of pedunculate oak (Quercus robur) in relation to environmental factors has been studied in Central Europe. However, there is insufficient information on oak growth in the Baltic region. Climate–growth interactions have been mostly investigated by correlation/response analysis between ring width and climatic factors. Other wood anatomical proxies, and also pointer year analysis, which focuses on weather extremes, can be sources of additional information. Wood samples were taken from 40 sites across Latvia. Tree-ring width (TRW) and mean area of earlywood vessels (EVA) were measured. To assess differences in wood formation among sites, a PCA was performed based on pointer year series of TRW and EVA per site. The relation with climate was assessed by Pearson's correlation. Patterns of wood formation differed along west/east gradient, so that two regions (western and eastern) of Latvia were distinguished. Pointer year values were higher for TRW than for EVA and higher in the eastern than in the western region. However, the pointer year values were moderate, suggesting that there was no strict limiting factor for their formation. Pointer years of EVA were strongly related with temperature during the dormant period in both regions; June precipitation had a significant effect in the eastern region. Pointer years of TRW were correlated with spring and summer temperature in the western region and with February temperature in the eastern region; precipitation in autumn showed a negative effect. These differences can be explained by a gradient from maritime to continental climate, leading to shifts in the growth limiting factors. Extremely cold winters resulted in most of the negative pointer years of TRW and EVA.     

Xylem water content and wood density in spruce and oak trees detected by high-resolution computed tomography

Elucidation of the mechanisms involved in long-distance water transport in trees requires knowledge of the water distribution within the sapwood and heartwood of the stem as well as of the earlywood and latewood of an annual ring. X-ray computed tomography is a powerful tool for measuring density distributions and water contents in the xylem with high spatial resolution. Ten- to 20-year-old spruce (Picea abies L. KARST.) and oak (Quercus robur) trees grown in the field were used throughout the experiments. Stem and branch discs were collected from different tree heights, immediately deep frozen, and used for the tomographic determinations of spatial water distributions. Results are presented for single-tree individuals, demonstrating heartwood and sapwood distribution throughout their entire length as well as the water relations in single annual rings of both types of wood. Tree rings of the sapwood show steep water gradients from latewood to earlywood, whereas those of the heartwood reflect water deficiency in both species. Although only the latest two annual rings of the ringporous species are generally assumed to transport water, we found similar amounts of water and no tyloses in all rings of the oak sapwood, which indicates that at least water storage is important in the whole sapwood.     

Dendrochronological analysis of white oak growth patterns across a topographic moisture gradient in southern Ohio

Moisture availability is a key factor that influences white oak (Quercus alba L.) growth and wood production. In unglaciated eastern North America, available soil moisture varies greatly along topographic and edaphic gradients. This study was aimed at determining the effects of soil moisture variability and macroclimate on white oak growth in mixed-oak forests of southern Ohio. Using accurately dated and measured tree rings, we analyzed 119 white oaks growing across an integrated moisture index (IMI), a computer-generated GIS model that simultaneously combines topographic and edaphic features into a moisture index scale. Growth trends varied considerably across the IMI, with trees in mesic sites exhibiting patterns much different from those in either xeric or intermediate sites. BAI growth and biomass increments were higher for trees growing in the intermediate and mesic sites than those from the xeric sites. Correlation and response function analyses, and redundancy analysis revealed significant relations between ring-width indices and climate, with current year May–July PDSI, precipitation and temperature as the most important correlates of white oak growth. Additionally, climatic influences on growth rate were variable across the IMI; trees in xeric sites showed much greater coefficients relative to those from the intermediate and mesic sites. Despite these differences, xeric and intermediate trees exhibited similar growth patterns. The present results provide further evidence of the usefulness of the IMI for identifying and comparing white oak growth patterns across the complex, dissected landscape of southern Ohio.     

Dendrochronological analyses of wood samples from a Late Bronze to early Iron Age site at Lake Luokesa,Lithuania

Tree rings of 184 archaeological wood samples from two Late Bronze to early Iron Age lake sites at Lake Luokesa (Luokesai e?eras), Lithuania, Moletai district, were analyzed. Despite severe difficulties with synchronization, Pinus (pine), Quercus (oak) and Alnus (alder) yielded some cross-datable series. The general picture is that the settlers chose small trees as timber, which they used in their natural round shape. The trees did not grow in homogeneous even-aged stands, but show very different ages and growth levels. Despite the generally low numbers of tree rings in the individual samples, the strong archaeological framework allowed cross-dating of some series and the building of chronologies for single structures. Based on these attempts, a 90 year long first floating chronology of the settlement structures is presented. Luokesa Site 2 (L2) was mainly built within the relative year 53. Luokesa Site 1 (L1) was certainly in use from the relative year 74 onwards. All fences at L1 show their main building activity in the relative year 81, four years after the main building activities in the village itself. It can be concluded that the settlement L1 was in use for at least 16 years. Because of the lack of a standard dendrochronological curve for the Baltic region, wiggle-matching was applied to obtain an absolute date for both settlements. The data clearly show that all samples relate to the Late Bronze–early Iron Age. The period where all wiggle matching results overlap is the period between 625 and 535 bc (the 2σ ranges are given). Based on the dating, duration and timber characteristics of the occupation, comparisons with Polish early Iron Age sites are made, which indicate a close resemblance in terms of wood use and settlement concept.     

Tree taxa immigration to the eastern Baltic region,southeastern sector of Scandinavian glaciation during the Late-glacial period (14,500–11,700 cal. b.p.)

The eastern Baltic region is situated in the southeastern part of the area which was covered by the last Scandinavian glaciation. Four well-dated sediment profiles from sites distributed along a ~330-km north–south transect were analysed for their macrofossil contents. The immigration of tree taxa during the Late-glacial (LG) period, which was the time of environmental change from tundra to woodland in previously glaciated areas, can be determined from these data. The pioneer vegetation in the study area was treeless dwarf shrub tundra with various dominant taxa. The so-called Allerød hemispheric warming permitted the Post-glacial immigration of trees into the southern part of the eastern Baltic region; however, these most probably disappeared during the following cold period, the Younger Dryas/GS-1. The local presence of Betula sect. Albae, Pinus sylvestris, Populus tremula and Picea abies during the LG period in the southern part of the region was confirmed. The northern part of the area presumably remained treeless for the entire LG period. Therefore, until the beginning of the Holocene, the tree line in the eastern Baltic region did not reach beyond 58°N.     

Parameter-specific hydroclimatic sensitivity of a low-elevation network of living and historical tree-ring series from north-eastern Austria

Compared to the alpine regions of Austria, the eastern part of the country is overall warmer and drier with some tree species growing at the dry limit within their ecological range. This suggests that tree rings may be a valuable proxy for hydroclimatic variability. In this study, we develop ring-width, earlywood-width and latewood-width chronologies obtained from drought sensitive living trees and historical timber from one of the driest and warmest regions of Austria, the Weinviertel. For this, samples of four different tree species − fir (Abies alba Mill.), spruce (Picea abies (L.) Karst.), oak (Quercus petraea Liebl., Q. robur L., Q. cerris L.), and pine (Pinus sylvestris L., P. nigra Arnold) were collected from 88 sites (23 forest stands and 65 historical constructions). 1589 samples (oak: 592 samples, pine: 577, spruce: 212, fir: 208) were dated. Dendro-provenancing was required to ensure that only regional material has entered the chronologies. According to the analyses, historical pine and oak wood were nearly 100% regional, while spruce and fir wood were imported to a great extent with only 44% spruce and 35% fir confirmed to be regional. Because site conditions of historical wood samples are unknown but can have a significant influence on tree growth, changes to site replication over time were important in the assessment of chronology reliability. We also controlled for potential artificial increases in sample depth when more than one construction element is made from a single trunk.We assessed the pine (1584-2011 AD) and oak (1244-2011 AD) chronologies’ potential for reconstructing past hydroclimatic variability by means of response functions in a 17-months window from previous June to current October with climate data from three weather stations (Vienna, Retz, Brno) from 1897 to 2010 AD. The highest seasonal response coefficients are for oak and pine ring width (∼0.43) with respect to aggregated March to July precipitation totals and Thornthwaite climatic water balance. These chronologies reveal a high potential for estimating past changes in regional-scale moisture availability during the earlier growing season.     

Medieval oak chronology from Klaipėda,Lithuania

Klaipėda is a town in western Lithuania on the Baltic Sea coast. Oak timber was actively used to construct buildings in this town until the 17th century. Archaeological investigations began in Klaipėda’s old town in 1979, but it has not been possible to use oak timbers for dating due to the lack of regional chronologies. The goal of this study was to fill this gap by developing a well-replicated oak chronology from timber collected in Klaipėda between 1979 and 1987. The resulting oak chronology from Klaipėda spans 306 years from 1247 to 1552 and includes 62 oak timber cross-sections. The study suggests that the timber was felled in the same local woodland, and that tree-ring widths series from Klaipėda are temperature-sensitive. The negative pointer years mostly coincide with negative anomalies of reconstructed April‒September temperature from elsewhere in Europe. The constructed chronology was compared with local chronologies (Vilquro, Smarhoń, Gdańsk) and with oak chronologies made from imported oak timber of southeast Baltic origin (Baltic 1–3, Dutch). We assessed whether it is possible to determine the origins of the Baltic 1, Baltic 3 and Dutch oak chronologies compiled from imported timber. Based on available chronologies, it could be hypothesised that Baltic 1 and Dutch chronologies are originated from western Lithuania and Baltic 3 from eastern Lithuania.     

Endophytes dominate fungal communities in six-year-old veteranisation wounds in living oak trunks

Old trees are rare in the landscape, as are many of their associated species. Veteranisation is a method by which attempts are made to create microhabitats, otherwise found only in old trees, in younger trees at an earlier stage than would occur naturally. Here, we analysed the early fungal succession in 6 y-old veteranisation wounds in ca. 100 y old living oak trunks by DNA-barcoding of the wood at eight sites in Sweden and Norway. We hypothesised basidiomycetes would be most abundant, and exposed sapwood and heartwood would select for different communities. We identified 686 fungal taxa, mainly ascomycetes, with a large overlap in species composition and surprisingly similar species richness, i.e. 325 vs. 308–360, between intact and different types of damaged wood, respectively. Endophytes continued to be present and common in damaged wood. The results demonstrate that damage to sapwood and heartwood partly select for different fungi and that 6 y is too early to evaluate if veteranisation can positively favour fungi of conservation interest.     

Relationship of heartwood traits with diameter growth, implications for genetic selection in Pinus radiata

The heartwood of radiata pine (Pinus radiata D. Don) is not favoured commercially because of its darker appearance, unreliable durability and difficulty to treat chemically; consequently, light-coloured sapwood, which is more easily treated with decay-resistant chemicals, is of more value. To decrease the amount of heartwood or increase sapwood cross-sectional area by genetic selection, the genetics of sapwood cross-sectional area (SWA), sapwood area percentage (SWAP) and number of heartwood rings (HWR) is of interest. We investigated genetic variation in these three variables from increment cores from trees from two trial series, each planted at two sites, from a total of some 330 families (189 were half-sib and 142 were full-sib) with 10 to 30 individuals assessed per family. Trials were assessed between 16 and 23 years old when all trees had started to develop heartwood. The three sapwood-related traits were moderately heritable across pairs of sites ( h ^ i 2 $ {\widehat{h}}_i^2 $ = 0.2 to 0.4) indicating opportunity for selection. SWA was strongly correlated (r _a ?=?0.9) with diameter. SWAP and HWR were also strongly correlated (r _a ?=??0.9). The number of HWR was independent of tree diameter, providing the opportunity through genetic selection to reduce heartwood area whilst increasing tree growth rate.     

From desert to rainforest, sapwood width is similar in the widespread conifer Callitris columellaris

The process that transforms conductive sapwood to non-conductive heartwood in trees is poorly understood. Here, we use natural variation in climate to examine the environmental control of sapwood width in a widespread conifer species. We hypothesised that if sapwood width is linked to transpirational load, there would be a positive association between sapwood width, and continental gradients in mean annual rainfall, whereas age-related conversion to heartwood would be revealed from estimates of the age of the inner-most sapwood ring. Using the widespread Australian conifer Callitris columellaris we took cores from trees at 85 sites spanning a range of 168–2,117 mm in mean annual rainfall, and 14–28 °C in mean annual temperature. We found that sapwood width was remarkably similar throughout the species range, being only slightly lower in the tropics than the arid or temperate zone. There was a weak negative relationship between sapwood width and mean annual rainfall, which is in the opposite direction expected from transpirational control of sapwood width. Sapwood growth rings were wider, but there were fewer of them in the tropics than elsewhere, indicating conversion to heartwood occurred earlier here. Together with an earlier finding that tracheid diameter was largest in the tropics, our results show that differences amongst climate zones more strongly influence the hydraulic properties of sapwood than its amount.     

The Influence of Growth Rings in Pinus patula on Heat Pulse Velocity and Sap Flow Measurement

Heat pulse velocity (HPV) apparatus was used to investigatethe relation between the radial HPV profile and the positionof growth rings in two Pinus patula trees (aged 4 and 7 years),growing in Frankfort State Forest in the eastern Transvaal,South Africa. Successive measurements of HPV at 3.0 mm intervalsalong each of four radii in each tree revealed a cyclical pattern,with maxima and minima correlated with summer and winter wood,respectively. We recommend that probe emplacement in fast-growingpines with relatively wide growth rings should be to randomly-assigneddepths in the sapwood. Confidence limits associated with samplemeans of wound-corrected HPV obtained with 4, 8 or 12 probesets were generated by simulating the repeated selection ofa randomly-chosen HPV measurement from each sapwood radius.We conclude from this analysis that a minimum of 12 point measurementsper tree is required to obtain an acceptable estimate of sapflow. In older trees where a decline in HPV is expected towardsthe centre of the trunk, sampling must be modified to avoidbias caused by deeper measurements representing proportionatelyless of the total sapwood area than those taken at more shallowdepths in the sapwood. Key words: Pinus patula, heat pulse velocity, sap flow, growth rings     

Evaluating the potential for dendrochronological analysis of live oak (Quercus virginiana Mill.) from the urban and rural environment—An explorative study

Live oak (Quercus virginiana Mill.) is a long lived, broadleaf, evergreen species native to the lower Coastal Plain of the southern and southeastern United States and is frequently planted in the urban environment. However, live oak has received limited attention for its potential for dendrochronological analyses possibly because its growth-ring boundaries may be less defined due to the absence of a distinct dormancy period. The objective of this explorative study was to determine whether live oak rings in both urban and historic trees could be accurately identified and measured for dendrochronological applications. One hundred urban live oaks were assessed as well as four cross-sectional specimens from historic sites in the southeastern United States. Age of all cored live oak ranged from 7 to 29 (average = 16.8 rings), while cross-sections were taken from trees with an average age of 175 years. A chronology was created from cores that had the highest interseries correlations (n = 27), resulting in an average interseries correlation of 0.654. The analysis of live oak cross sections revealed that the rings on live oak are very faint and barely discernible, delimited mainly by a faint row of earlywood vessels with no or barely visible terminal parenchyma. Rings on these sections were erratic (i.e., fading out along the circumference) and non-concentric (i.e., a particular ring could be both wide and narrow at certain points along the circumference) so that any attempt to measure the rings on opposing radii would have produced meaningless results. However, based on the results of this study, we conclude that the dendrochronological analysis of live oak is possible with careful sample preparation and analysis and that results would be reliable, even for urban trees. Results of this study suggest that urban tree-ring series with higher interseries correlations were more vigorous than those with lower values, suggesting that urban environmental stresses related to individual sites may decrease the usefulness of crossdating techniques for evaluating annual rings on younger, urban trees.     

Reactions of the fauna on the bark of trees to the frequency of fires in a North American savanna

Summary The arthropod communities living on the bark of the oak species Quercus macrocarpa and Q. ellipsoidalis were investigated in a North American oak savanna. Differences were found in the community structure of the arthropods living on the bark of these two tree species, although they have the same fissured bark type. In the North American oak savanna ecosystem the most important disturbance factor is fire, which maintains species richness. Highest numbers of species and specimens were found at moderately disturbed sites. Three main ecological groups of arthropods living on the bark of trees can be distinguished in relation to the degree of disturbance: (1) Inhabitants of bark of trees restricted to undisturbed sites: they do not occur in fire-disturbed areas; (2) Inhabitants of bark of trees adapted to a moderate degree of disturbance: many species occur in high numbers only in moderately disturbed areas; and (3) Specialist inhabitants of bark of trees in heavily disturbed areas. The number of specimens of these species increases per trunk with the frequency of disturbance.     

Blue mussels (Mytilus edulis) in the diet of roach (Rutilus rutilus) in outer archipelago areas of the western Gulf of Finland,Baltic Sea

The blue mussel (Mytilus edulis) is one of the key species in the Baltic Sea ecosystem and it is living at the edge of its range in the western Gulf of Finland. Roach (Rutilus rutilus) is a freshwater fish species that has benefited from recent coastal eutrophication and is at present highly abundant in the outer archipelago of the Gulf of Finland. In 2000 and 2001, a total of 516 roach were sampled for diet analysis in three study areas. Shelled molluscs formed over 95% of the diet of roach, blue mussels being the dominant single species. The proportion of this species in the food of roach in the three study areas ranged between 38–61% for smaller roach (<225 mm) and 39–85% for larger (>225 mm) roach, indicating that blue mussel is a highly important food source for roach in outer archipelago areas of the western Gulf of Finland, in contrast to reports from other parts of the northern Baltic Sea. The scarcity of large blue mussels in mussel beds in the easternmost study area was reflected in the lower proportion of blue mussels in the diet of larger roach. However, the growth of roach was not affected by the availability of blue mussels. The twofold differences observed in the annual growth of roach between warm and cold years demonstrated that temperature is an important factor controlling the growth of roach in the western Gulf of Finland.     

Climate response of cork growth in the Mediterranean oak (Quercus suber L.) woodlands of southwestern Portugal

In the Mediterranean climate regions, drought events are expected to affect the growth of forests ecosystems by changing trees growth rates and eventually inducing shifts in their growth patterns. Cork oak (Quercus suber L.) is a strictly western Mediterranean tree species periodically harvested for its bark, the cork. So far, cork oak has received limited attention for dendroclimatological studies due to its typical faint and erratic tree wood rings. Moreover, its distinct cork rings chronologies have been completely neglected. In this study we introduce an approach using cork ring chronologies dated back 9–10 years for climate response. Despite enhancing interannual variability and increasing statistical response to short-term climatic variability, still poorly understood, this study will possibly allow infer long-term climate response. We analyzed the cork ring chronologies of 55 cork samples collected in mature (under exploitation) trees in three distinct locations in southwestern Portugal. Cork growth recorded a high climate signal, with highly significant and coherent responses to the yearly climate-related sources of variation. We successfully assessed trends of cork growth via correlation analysis including selected climate variables among mean monthly temperature, monthly precipitation and, on an annual basis, eight precipitation indices. The high mean sensitivities and inter-series correlations found for cork ring chronologies combined with the significant variance explained by climate variables suggest that climate is likely one dominant signal that affects cork growth, but local environmental stresses can decisively affect this (climate) signal. Assuming cork growth as a proxy for cork oak growth, it seems conceivable that despite the trees being highly resistant to drought stress, cork oak woodlands in southwestern Portugal would have to face lesser growth in a global warming scenario.     

The beginnings of rye (<Emphasis Type="Italic">Secale cereale</Emphasis>) cultivation in the East Baltics

In this paper we review the earliest Secale (rye) records, both pollen and macroremains, from the eastern Baltic region (northeast Poland, Lithuania, Latvia, Estonia and Finland) in order to understand the processes evident in the beginnings of rye cultivation. By taking note of the abundance of recovered Secale grains and pollen in relation to other cereals found in published archaeobotanical data, we try to understand when rye began to be used regionally as a staple food. The clarification of the timing of Secale in the East Baltic, that had social and economic implications, is of particular importance. In this publication we also present a radiocarbon date directly derived from dating a Secale grain from a Roman period hillfort in Lithuania. The date obtained constitutes the earliest record of Secale in the eastern Baltic region, showing that rye cultivation traditions and concomitant innovations in agricultural technology started there much earlier than previously suggested.