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While the isotopic composition of strontium (87Sr/86Sr) is frequently used in archeological and environmental provenience studies, it remains unclear how bioavailable Sr in organic matter and the food chain reflects bedrock sources. Here, we present Sr isotopic measurements of 24 soil and 120 wood samples from four central European forests with variable basement geology. While 87Sr/86Sr values in bedrock (0.7035–0.7441) and soil (0.7043–0.7552) have a considerable span, wood 87Sr/86Sr values across sites have a much smaller range (0.7041–0.7245), which is closer to the large‐scale atmospheric Sr signature in precipitation (0.7118). Comparable 87Sr/86Sr ratios for different tree species, cambial ages and root systems suggest that bioavailable Sr in wood is little affected by biotic factors. Given the strength of the atmospheric Sr signal we identify, archeological, environmental and forensic fingerprinting should consider high‐resolution spatial isoscape modeling, for which this study provides a baseline for central Europe.

Europe’s recent summer droughts have had devastating ecological and economic consequences, but the severity and cause of these extremes remain unclear. Here we present 27,080 annually resolved and absolutely dated measurements of tree-ring stable carbon and oxygen (δ 13 C and δ 18 O) isotopes from 21 living and 126 relict oaks ( Quercus spp.) used to reconstruct central European summer hydroclimate from 75  bce to 2018  ce . We find that the combined inverse δ 13 C and δ 18 O values correlate with the June–August Palmer Drought Severity Index from 1901–2018 at 0.73 ( P  < 0.001). Pluvials around 200, 720 and 1100  ce , and droughts around 40, 590, 950 and 1510  ce and in the twenty-first century, are superimposed on a multi-millennial drying trend. Our reconstruction demonstrates that the sequence of recent European summer droughts since 2015  ce is unprecedented in the past 2,110 years. This hydroclimatic anomaly is probably caused by anthropogenic warming and associated changes in the position of the summer jet stream. European summer droughts in recent years are anomalously severe compared with those of the previous 2,000 years, according to a synthesis of annually resolved tree-ring carbon and oxygen isotope records.

The forests of central Europe have undergone remarkable transitions in the past 40 years as air quality has improved dramatically. Retrospective analysis of Norway spruce ( Picea abies ) tree rings in the Czech Republic shows that air pollution (e.g. SO 2 concentrations, high acidic deposition to the forest canopy) plays a dominant role in driving forest health. Extensive soil acidification occurred in the highly polluted \"Black Triangle\" in Central Europe, and upper mineral soils are still acidified. In contrast, acidic atmospheric deposition declined by 80% and atmospheric SO 2 concentration by 90% between the late 1980s and 2010s. In this study we oserved that annual tree ring width (TRW) declined in the 1970s and subsequently recovered in the 1990s, tracking SO 2 concentrations closely. Furthermore, recovery of TRW was similar in unlimed and limed stands. Despite large increases in soil base saturation, as well as soil pH, as a result of repeated liming starting in 1981, TRW growth was similar in limed and unlimed plots. TRW recovery was interrupted in 1996 when highly acidic rime (originating from more pronounced decline of alkaline dust than SO 2 from local power plants) injured the spruce canopy, but recovered soon to the pre-episode growth. Across the long-term site history, changes in soil chemistry (pH, base saturation, Bc/Al soil solution ratio) cannot explain observed changes in TRW at the two study sites where we tracked soil chemistry. Instead, statistically significant recovery in TRW is linked to the trajectory of annual SO 2 concentrations or sulfur deposition at all three stands.

Though tree-ring chronologies are annually resolved, their dating has never been independently validated at the global scale. Moreover, it is unknown if atmospheric radiocarbon enrichment events of cosmogenic origin leave spatiotemporally consistent fingerprints. Here we measure the C-14 content in 484 individual tree rings formed in the periods 770-780 and 990-1000 CE. Distinct C-14 excursions starting in the boreal summer of 774 and the boreal spring of 993 ensure the precise dating of 44 tree-ring records from five continents. We also identify a meridional decline of 11-year mean atmospheric radiocarbon concentrations across both hemispheres. Corroborated by historical eye-witness accounts of red auroras, our results suggest a global exposure to strong solar proton radiation. To improve understanding of the return frequency and intensity of past cosmic events, which is particularly important for assessing the potential threat of space weather on our society, further annually resolved C-14 measurements are needed.

In the present study, anatomical features were used to identify tree species chosen to craft farming tools from the 19th and first half of the 20th century preserved in specimen inventories of the open-air museum in Strážnice, south-eastern Moravia (Czech Republic). In total, 701 samples from 337 historical farming tools were obtained from museum specimens. The samples were identified at micro- or macroscopic levels, or both. Results indicated local people used floodplain forest wood to construct farming tools in the study region. Nineteen wood species were identified; from this total, those with higher densities and better mechanical properties were used to manufacture tools, and included predominantly beech, oak, and ash. Softwood species, with lower densities were mainly used for chiseled out implements. We hypothesized regional forest species composition played an essential role in woody species choice, however the species also possessed appropriate properties. Cultivated tree species, such as fruit trees, were employed to create common objects; however, currently, these species are typically applied for special purposes. We concluded an increased number of species were employed in the past for utilitarian purposes, including tree species grown outside local forest boundaries, including cultivated fruit tree species; and species were utilized with good, although perhaps tacit, knowledge of their properties.

Climatic variability inevitably impacted past societies and acted as a driver of change. The combined analyses of the archaeological record and written documentary sources, together with high-resolution climate reconstructions, remain rare. In this work, we compare evidence of change at the Germanic settlements (residential areas) of Iron Age Germanic societies in the Middle Danube region (the region of Moravia in the Czech Republic, Lower Austria and the Záhorie region in Slovakia) and reconstruct the effect of agroclimatic conditions during the first four centuries CE. Based on data from 773 residential areas with temporal identification, we demonstrate a coherent relationship between spatiotemporal changes in Germanic settlement structures and agroclimatic conditions. A nearly exponential increase in settlement structure during the 1st and half of the 2nd century CE coincided with improved agroclimatic conditions, whereas the subsequent settlement structure decline during the Late Roman Period temporally overlapped with agroclimatic deteriorations. Documented peak in cessations of residential areas in the late 2nd century CE appears unrelated to regional agroclimatic conditions and was instead caused by the Marcomannic Wars. We argue that separating periods of agroclimatic importance and insignificance is the first step towards identifying possible causal environmental drivers of settlement dynamics and societal change in the Middle Danube region.

The radial growth of temperate forests responds to climate change with remarkable variation across space and between species. However, there is limited understanding of how growing season extension and increasing drought stress contribute to long-term growth trends. Here, we calibrate the VS-Lite growth model using 2013 tree-ring chronologies from ten broadleaved and five coniferous genera in Central-Southeast Europe to predict intra-annual wood formation under four SSP climate scenarios through the 21 st century. Results show that forecasted summer drought stress will be temporarily offset by an extended growing season, leading to stable or positive trends in tree-ring widths until a tipping point in the 2040s–2050s. During the second half of the 21 st century, high-emission scenarios lead to growth acceleration in humid coniferous forests due to growing season extension and enhanced growth rate. In contrast, forecasted extension of the growing season is insufficient to compensate for declining summer growth rates at drier sites, resulting in significant growth reduction for all genera, particularly during dry years. Our results demonstrate that adjusting intra-annual wood formation to seasonal moisture availability may become crucial for tree survival in warmer climates. Furthermore, we highlight that only low-emission scenarios support non-declining stem growth in dry forests with current species composition. This study forecasts intra-annual forest growth towards the end of the 21st century under different scenarios of climate change. It predicts that the extension of the growing season will not be sufficient to compensate for the future drought-induced summer growth limitation.

Central Europe has experienced a sequence of unprecedented summer droughts since 2015, which had considerable effects on the functioning and productivity of natural and agricultural systems. Placing these recent extremes in a long-term context of natural climate variability is, however, constrained by the limited length of observational records. Here, we use tree-ring stable oxygen and carbon isotopes to develop annually resolved reconstructions of growing season temperature and summer moisture variability for central Europe during the past 2000 years. Both records are independently interpolated across the southern Czech Republic and northeastern Austria to produce explicit estimates of the optimum agroclimatic zones, based on modern references of climatic forcing. Historical documentation of agricultural productivity and climate variability since 1090 CE provides strong quantitative verification of our new reconstructions. Our isotope records not only contain clear expressions of the medieval (920–1000 CE) and Renaissance (early sixteenth century) droughts, but also the relative influence of temperature and moisture on hydroclimatic conditions during the first millennium (including previously reported pluvials during the early third, fifth, and seventh centuries of the Common Era). We conclude that Czech agricultural production has experienced significant extremes over the past 2000 years, which includes periods for which there are no modern analogs.

Tree stems represent a long-lived biomass compartment for atmospheric carbon sequestration. While terrestrial biosphere models predict rising carbon sequestration in forests, direct observations of tree growth are inconclusive due to varying standardization procedures of tree-ring series and complex factors influencing stem growth such as moisture and nutrient deficits and anthropogenic carbon and nitrogen fertilization. The mismatch between tree-ring-based observations, repeated inventories at permanent plots, and predictions of biospheric models represents a significant knowledge gap limiting forecasting of future forest growth. Using the novel approach free of tree-ring standardization trials and focusing on even-aged trees sampled from uneven-aged forest stands, we present a robust comparison of tree stem diameter changes in temperate forests between 1990 and 2015 along environmental gradients in Central Europe. The stem sizes of four out of five species showed significant enlargement while also partly increasing stem growth limitation due to moisture availability. The largest increase in stem diameter was recorded for late succession species on fertile sites. By contrast, the stem size of early-succession species on dry and nutrient-poor sites remained unaltered. Stems of mature trees in present-day forests are, on average, 8% thicker than their counterparts in 1990 consistent with trends predicted by terrestrial biosphere models. We demonstrated that, despite increasing drought limitation, temperate tree species enlarged their stems. Viewed in conjunction with older permanent plot data, Central-European temperate forests exhibited almost half century of continuous stem enlargement, potentially impacting forest functioning in terms of size-sensitive characteristics such as susceptibility to drought and disturbances.

The radial growth of trees significantly contributes to climate change mitigation by sequestering carbon into woody biomass. Radial growth trends observed in European temperate forests during the recent period of climate warming vary between growth acceleration due to longer growing seasons and growth declines due to amplified drought stress. Assessing the spatial variation of growth trends is challenging due to the point relevance of available empirical data including forest inventories and tree-ring width chronologies. Here, we used a database of tree-ring width chronologies from 596 sites and spatial models to describe the growth trends of five tree species across the Czech Republic between 1990 and 2018. The resulting map highlights multiple sources of variation in growth trends including differences between species and prominent spatial gradients along elevation, latitude, and longitude. The knowledge of spatially explicit growth trends is essential for the adaptation of the forestry sector to ongoing climate change. Differences among species, regions, and over time shape current growth trends of European temperate forests. Abies alba shows mostly positive growth trends. By contrast, Fagus sylvatica and Picea abies currently decline across most of their species ranges. Growth trends shift from negative to positive with increasing elevation for species covering a broad elevation range. The growth trends of some species follow latitudinal (Abies alba) or longitudinal (Quercus spp.) gradients. The growth trends tend to be more negative in the recent period 2005-2018 compared to the 1990-2005 baseline for most species and regions.