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Climate influences tree-ring density and ring-density variables extracted from X-ray images have been widely used for climate reconstructions. The R package xRing was developed to identify and measure tree rings on X-ray microdensity profiles automatically. This package is available for free and it offers functions to visualize and calibrate X-ray images, to detect tree-ring borders and to identify earlywood-latewood transition using wood density variations at the inter- and the intra-ring scale. The most important functions are calibrateFilm, detectRings, correctRings, detectEwLw, and getDensity. Outputs of these functions are S3 objects, for which specific methods are provided, including plot and print. The non-linear relationship between optical density of the film and wood density is defined by the function calibrateFilm. The function detectRings detects tree rings using wood density profiles as input. This function uses the difference between local maximum and minimum values to identify tree-ring borders automatically. The correctRings function is used to call a Graphical User Interface (GUI) to visualize and to correct tree-ring borders manually. After correcting tree-ring borders, the detectEwLw function is used to compute earlywood and latewood widths by dividing rings according to relative intra-ring density changes. The getDensity function computes for each tree ring the minimum (maximum) density and the mean earlywood, latewood and whole-ring density. Finally, a list with dataframes with tree-ring width and density variables can be obtained using the function getRwls. One of the major advantages of xRing package is that requires little knowledge of R language, but at the same time it can be easily changed or adapted by experienced users.

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.

The prehistoric salt mine of Hallstatt together with its burial ground is one of the most prominent archaeological sites in the world, and has given its name to the “Hallstatt period”, an epoch of European prehistory (800 to 400 BCE). Due to the perfect conservation in rock salt a high number of organic materials have been found, including mostly wooden artefacts and structural timber. More than 2000 samples were taken from various archaeological sites in the mines as well as at the surface. It was possible to date 763 samples by the means of dendrochronology and by 14C wiggle matching. The dendrochronological dating was possible due to crossdating with various available chronologies (like Villingen-Magdalenenberg or Dachstein/Schwarzer See). The fir (Abies alba Mill.) chronologies span the periods: -1232 to -1063; -819 to -425 and -371 to-129. The spruce (Picea abies L. Karst.) chronologies span the periods: -1228 to -1063; -813 to -669 and -342 to -123. The larch (Larix decidua Mill.) chronologies span the periods: -1393 ± 18 to-1286 ± 18 based on wiggle matching data and -252 to -164. A beech (Fagus sylvatica L.) chronology span the time -1182 to -1062.

Castle Pisece, located in SE Slovenia near the border with Croatia, is thought to have been built in the 12th/13th century as one in the line of Salzburg fortresses on the then SE border of the Holy Roman Empire. During thorough restoration that started in 2005, its wooden constructions became accessible for dendrochronological investigations. We collected representative samples from floor or ceiling constructions in most of the rooms in the castle. Dendrochronology helped us to identify felling dates of wood and to propose probable years of reconstructions in 1515, 1578, 1644, 1697, 1752, 1758, 1775 and 1878. The dating showed that the constructions in the presumed Romanesque and Renaissance parts of the building were not as old as expected, whereas those in the supposedly Baroque part of the castle were older than assumed. The selection of wood species used for constructions varied over time. Constructions with end dates 1515–1697 were made of oak (Quercus petraea and Q. robur), those dated to 1752 of silver fir (Abies alba), those dated to 1758 of sweet chestnut (Castanea sativa) and those dated to 1878 of common beech (Fagus sylvatica). Comparison of forestry archives and vegetation in the area showed that most of the timber could have originated from nearby forests; only silver fir had to be transported from sites that were at least 20 km away from the castle. Cross-dating of tree-ring series of oak elements with two reference chronologies from Slovenia and two from Austria confirmed the great likelihood that the wood used mostly originated from Slovenia. This indicates that dendroprovenancing, not used in the area before, could also be used SE of the Alps. Both the existing archival documents and dendrochronology indicate that woodworks have taken place every few decades in some periods. The dendrochronological dates can be partly linked to reports on earthquakes (especially the devastating one in 1511), rebellions and year marks carved on the stone plaques.

In the present study, 208 furniture and 168 coopered vessels from three Austrian museums were examined. Dendrochronology was used to date objects and to extract further information such as the necessary time for seasoning, wood loss through wood-working and methods of construction. In most cases sampling was done by sanding the cross section and making digital photographs using a picture frame and measuring digitally. The dendrochronological dates of the sampled furniture range between 1524 and 1937. The group of furniture includes cupboards, chests, tables, benches, commodes and beds. In many cases furniture was artfully painted and sometimes even shows a painted year. With the help of dendrochronology it was proved that some objects had been painted for some time after construction, or had been over-painted. Most furniture, however, was painted immediately after completion. In this case, the seasoning and storage time of the boards and the wood loss due to shaping can be verified. As an average value, 14 years have passed between the dendrochronological date of the outermost ring and the painting. The time span includes time of seasoning and storage and the rings lost by wood-working. This leads, on the one hand to a short storage time of less than 10 years and on the other hand to very little wood loss due to manufacturing. Those boards being less shaped turned out to be back panels of cupboards, therefore they are recommended to be sampled for dating. Coopered vessels were dated between 1612 and 1940. There was evidence that staves were split and not sawn in many cases. The staves were often split out of the outermost part of the tree and hardly any wood was worked away which was proved by the close dendrochronological dates of the single staves of a vessel. Since there is a short time of storage and only little wood loss through wood-working, dating of objects without a waney edge becomes reasonable.

Cubic smoothing splines with a fixed-period response are used widely in producing “expected” growth curves for ring-width and density data in dendroclimatology. A simple modification to the procedure which generates these splines enables the use of a smoothing spline with a user-specified, time-varying flexibility and hence time-varying-response characteristics. The revised procedure is presented here, along with different examples of its application in the context of Regional Curve Standardisation (RCS). The ability to generate a smoothing spline with time-dependent flexibility may have wider application in tree-ring studies.

Axial variation of latewood-widths and -stable isotopes ( δ 13 C and δ 18 O) of a single sessile oak tree ( Quercus petraea (Matt.) Liebl.) was analyzed. The influence of sampling height was found to be weak for both, latewood-widths and -stable isotopes in the latewood. The observed trends with stem-height show clearly that possible effects due to cambial aging are overrated by annual effects. In addition, relations between samples from different stem-heights are strong for identical calendar years while they are poor for identical cambial age. This indicates that samples from both, living trees and historical wood can be taken from any height position of a trunk or beam as long they are free from anatomical abnormities. Simple correlation and Gleichlaufigkeit were used for validation.

The prehistoric salt mine of Hallstatt together with its burial ground is one of the most prominent archaeological sites in Austria, which has also given name for the “Hallstatt period” of human civilisation (800–400 BC). Due to the perfect conservation in rock salt a great number of organic materials have been found, among mostly wooden artefacts. Currently, the major archaeological focus is on the Bronze Age salt mining activities with excavations taking place at the historic Christian von Tusch-Werk, Alter Grubenoffen mine. Chronology building started at the Dachstein plateau, in the vicinity of Hallstatt, where tree-trunks were discovered in an alpine lake (Schwarzer See) and after recovery a spruce-larch chronology was compiled that dates back to 1475 BC. In addition, at the bog Karmoos, very close to the mining place of Hallstatt, preserved trees were intensively sampled resulting in a spruce chronology reaching even 1523 BC. Over 500 samples were taken at the Christian von Tusch-Werk, Alter Grubenoffen. They also included samples from the recently discovered world's oldest wooden staircase. The spectrum of wooden species encompassed Norway spruce, Silver fir, beech, European larch and maple. We were able to synchronize 128 samples, ending in a 282-year long floating chronology. While the staircase dated back to 1344 BC, the end year of the floating chronology dated even to 1245 BC. Tree felling dates showed clusters within the chronology, providing evidence for archaeologists to find construction phases and usage periods. The Dachstein–Hallstatt spruce chronology currently holds 840 synchronized series, and includes samples from the lake at the Dachstein, from the Karmoos bog at Hallstatt, from the prehistoric Hallstatt salt mine, and from historical buildings, as well as living trees. The chronology covers the period between 1523 BC through 2004 AD.

Variability of wood parameters in a tree is sometimes a rather nebulous concept since variability is evident within single cells, from early to latewood, from pith to bark and from stem base to the top of a tree. So far, stem analyses have been done using a restricted number of parameters, mostly ring-width, and using a restricted number of samples in the longitudinal direction. This study analyses a number of parameters from a single tree. An 81-year-old spruce tree was felled and internodial discs were taken from each annual terminal shoot. All tree rings in each disc were measured and a whole-stem analysis was completed for the following parameters: ring-width, mean ring density, maximum density, percentage of latewood, type of transition from early to latewood, intra-annual density fluctuation, number of resin ducts per tree-ring and position of resin ducts within the tree-rings. All parameters showed calendar-year patterns, visible as lines parallel to the bark. The most clear calendar-year pattern was seen for the type of transition from early to latewood and for intra-annual density fluctuations. The strongest inter-series correlation between calendar rings was seen for ring-width. None of the parameters showed significant inter-series correlations for cambial rings. These results may help us to understand how cores or discs taken at breast height represent the entire tree.

Summary The watersheds of the rivers Enns and Steyer border the Reichraminger Hintergebirge. This area has a long tradition in the iron processing industry. Because mineral coal was not available, charcoal has been produced for the iron industry for the past 500 years, leading to a heavy exploitation of the vast forests (180 km 2 ). From the logging sites in the mountains the timber had to be transported up to 12 km to the forges in the lowland. Most of the small rivers had insufficient water to drift logs efficiently. Therefore, at gorges or at places where there were narrow steep sided valleys wooden dams (klausen) were built to block the water, using the first cut trees of a newly targeted harvesting area. By abruptly opening the dams, the rapid flow of the raised water level carried the logs to the next klausen. Up to seven klausen were built in a valley before the rechen (rake-like grids within the river to collect the logs) of the Enns and Steyer were reached. To reconstruct the history of log drifting in the Reichraminger Hintergebirge, 33 klausen and rechen were visited and dendrochronologically sampled. The remaining wood of the dam constructions showed progressive stages of degradation, and in some cases only a few logs remained preserved under the water. With cores from living trees added to the dataset, master chronologies were established for spruce (576 years), fir (569 years) and larch (342 years). The construction history of the klausen can be sequentially traced back to 1563 AD. The time spans of the individual chronologies varied between 40 and 392 years. All available conifer species were utilized to build the dams, except during the 19th century, when the most suitable species - larch - was used to a higher degree.

This paper presents a multi-century, maximum latewood density (MXD) chronology developed from living and sub-fossil spruce trees from the Eastern Alps. The chronology is continuous from 88AD to 2008AD. This time series has been analysed with respect to its possible use for climate reconstruction. Correlations with climatic data showed strong dependence between MXD of growth rings and temperature of April, May, June, July, August and September and a weaker, negative dependence with precipitation of May and September. For solar radiation a positive relationship was noted for April, July, August and September. Light rings were frequently observed within the analysed samples and the climate of years with light rings was examined. Mean monthly temperatures in January, June, August, September and October, averaged during light ring years, were cooler than during years without light rings. Precipitation was also significantly reduced in March during light ring years. In turn, solar radiation during light ring years has significantly lowered values in February and August. The occurrence of light rings was often positively related to strong volcanic events.