Sites In Central Europe Research Articles

TreeCompR: Tree competition indices for inventory data and 3D point clouds

Abstract In times of more frequent global change‐type droughts and associated tree mortality events, competition release is one silvicultural measure discussed to have an impact on the resilience of managed forest stands. Understanding how trees compete with each other is therefore crucial, but different measurement options and competition indices (CI) leave users with a difficult choice, as no single competition index has proven universally superior. To help users with the choice and computation of appropriate indices, we present the open‐source TreeCompR package, which handles 3D point clouds and classical forest inventory data, enabling the calculation of both innovative point cloud‐based indices and traditional distance‐dependent indices. It serves as a centralized platform for exploring and comparing different CIs, allowing users to test and select the most suitable CI for their specific research questions within a common interface. To evaluate the package, we used TreeCompR to quantify the competition situation of 307 European beech trees from 13 sites in Central Europe. Based on this dataset, we discuss the interpretation, comparability and sensitivity of the different indices to their parameterization and identify possible sources of uncertainty and ways to minimize them. The compatibility of TreeCompR with different data formats and different data collection methods makes it accessible and useful for a wide range of users, specifically ecologists and foresters. Due to the flexibility in the choice of input formats as well as the emphasis on tidy, well‐structured output, our package can easily be integrated into existing data‐analysis workflows both for 3D point cloud and classical forest inventory data.

Short high-accuracy tritium data time series for assessing groundwater mean transit times in the vadose and saturated zones of the Luxembourg Sandstone aquifer

Abstract. Among the manifold of environmental tracers at hand, tritium is the only one that can give information on groundwater age within the timescale of 100 years for the entire flow system, i.e., unsaturated and saturated. However, while in the Southern Hemisphere, a single water sample is sufficient for tritium-based young groundwater dating, several tritium measurements spanning multiple years are still needed in the Northern Hemisphere to disentangle the natural cosmogenic tritium input from that caused by the atmospheric thermonuclear weapons tests mainly carried out in the early 1960s. Although it is advised to focus tritium dating on sites where long chronicles of tritium data are available, in this study we tested the potential for short high-accuracy tritium data series (∼4 years) to date groundwater from 35 springs draining the Luxembourg Sandstone aquifer (central western Europe). We determined groundwater mean transit times using the lumped-parameter model approach in a Monte Carlo uncertainty estimation framework to provide uncertainty ranges inherent to the low number of tritium data at hand and their related analytical errors. Our results show that unambiguous groundwater mean transit time assessments cannot be determined solely based on such recent short tritium time series, given that several ranges of mean transit times appeared theoretically possible. Nonetheless we succeeded in discriminating groundwater mean transit times in the vadose and saturated zones of the aquifer through a stepwise decision process guided with several supplementary data. The mean transit time required for water to cross the vadose zone was estimated to be between 0.5±0.5 and 8.1±1.2 years depending on the spring, while for water to flow through the saturated zone, it varied from 5.7±2.4 to 18.9±4.6 years (median ± half of the 5–95 percentile range). Our findings are consistent with both the tritium measurements of individual springs and the hydrogeological context of the study area. We specifically corroborated the dating results using the known hydrogeological properties of the Luxembourg Sandstone aquifer, the hydrochemistry of the studied springs, and their discharge dynamics. When translated into water velocities (which average ∼12 and ∼170 m yr−1 for the vadose and the saturated zones, respectively), the tritium dating results mirrored the horizontal–vertical anisotropy of the aquifer's hydraulic properties caused by the bedded character of the Luxembourg Sandstone. In addition to improving our understanding of water transit times in the Luxembourg Sandstone aquifer, this study demonstrates how it is currently possible to use short tritium time series to date young groundwater bodies at new sites in central Europe.

In vitro effect-based monitoring of water, sediment and soil from a floodplain restoration site in Central Europe

BackgroundFloodplains are biodiversity hotspots and provide numerous ecosystem services. In recent decades, however, 70–90% of Europe’s floodplains have been structurally degraded. Accordingly, many (inter-)national programs aim to restore and protect floodplain ecosystems. The success of such measures also depends on the chemical contamination, especially of floodplain soils and sediments, which serve as sinks and sources for a variety of pollutants. In this study, we assess the current ecotoxicological status of a floodplain restoration site along the Main River (Frankfurt am Main, Germany) and estimate its development potential with respect to the influence of a local industrial plant and potential legacy contaminations. We therefore use in vitro effect-based methods (EBMs) testing for baseline toxicity, mutagenicity, dioxin-like and estrogenic activities, coupled with chemical analysis.ResultsOf all water bodies analyzed, the overall toxicity was highest in two flood depressions. In the respective water phase, estrogenic activities exceeded the environmental quality standard and sediment samples were positive for all tested endpoints. Chemical analysis of these sediments revealed high concentrations of polycyclic aromatic hydrocarbons. Soil samples from frequently flooded areas showed the highest mutagenic potential for both frameshift and point mutations with and without metabolic activation. The industrial effluent showed baseline toxic, mutagenic, and dioxin-like activities, that were highly diluted in the Main River. In turn, most of the sediment samples downstream of the industrial discharge showed significantly elevated baseline toxic, estrogenic and dioxin-like activities as well as increased chemical contamination.ConclusionBased on the results of this study, we rate the overall ecotoxicological status of a recently established tributary and groundwater-fed ponds as good, and identified two flood depressions near the Main River as hot spots of contamination. We assume that the observed mutagenicity in the floodplain soils is related to legacy contaminations from former aniline and azo dye production. In terms of the development potential of the floodplain restoration site, we emphasize considering the remobilization of pollutants from these soils and suppose that, in the long term, pollution of the Main River and the local industrial plant may negatively impact sediment quality in its tributaries. With this study, we confirmed the utility of in vitro EBMs for identifying chemically and ecotoxicologically relevant sites.

Drivers of autochthonous malaria cases over time: could the Central European present the African future?

BackgroundResults of spatial and temporal comparison of malaria hotspots and coldspots could improve the health measures of malaria control and eradication strategies. The study aimed to reveal the spatially and temporally independent correlations between the potentially most effective background variables and the number of autochthonous malaria cases.MethodsRelationships between malaria cases and background variables were studied in 2 km × 2 km sized quadrates (10 Central European and 10 African). In addition to the current habitat structure of the African sites, annual precipitation, and annual mean temperature, data of the above parameters detected in the nineteenth and twentieth centuries and currently in the Central European sites were included in the analyses (n = 40). Mann–Whitney tests, Principal Component Analysis, and Generalized Linear Models were used for the examinations.ResultsIn addition to the apparent significant positive correlation of malaria cases with annual rainfall and mean temperature, several correlations were found for habitat parameters. The cover of marshlands in the 19th-century habitat structure of Central European quadrates was considerably the same as in the recent African ones. The extent of rural residential areas was significantly smaller in the 19th-century habitat structure of Central European quadrats than in present-day African ones. According to the revealed correlations, the surface cover of rural residential areas is the main driver of the number of autochthonous malaria cases that we can directly impact.ConclusionsThe study confirmed with historical comparison that not only the annual rainfall and mean temperature, the cover of marshlands and other habitats with breeding sites, but also the elements of the rural human environment play a significant role in the high number of autochthonous malaria cases, probably through the concentration and enhancing sites for vector mosquitoes. The latter confirms that a rapid urbanization process could reduce malaria cases in the most infected areas of Africa. Until the latter happens, extensive biological control of Anopheles larvae and chemical control (both outdoor and indoor) of their imagoes, further mosquito nets, repellents, and carbon dioxide traps will need to be applied more widely in the most heavily infested areas.

Poor convergence between local traditional farmers and conservationists on which species to protect locally

Abstract Locals engaged in traditional farming and possessing traditional ecological knowledge consider certain species worthy of protection, as do official nature conservationists, although the sets of taxa may not be identical. Exploring the relationship between the two sets of taxa could bring many practical benefits, yet the literature on this subject is scarce. For more efficient conservation and better engagement and knowledge co‐production with locals, it is necessary to understand the principles, preferences and worldviews of the two knowledge systems, and the drivers behind the choices of which animal species to protect. We examined which animal species traditional farmers and conservationists wish to protect, and why. We also examined whether there is a correlation between the extent of farmers' ecological knowledge and the number of species they regard as needing protection. In the case of the species that conservationists consider most in need of protection, we also enquired how knowledgeable local farmers are about these species. Our research was carried out in two adjacent protected sites in Central Europe along the Slovenian‐Hungarian border. We conducted 20 structured interviews with traditional farmers at each of the two sites (40 altogether), and 23 with local conservationists. Both conservationists and local farmers predominantly mentioned the protection of species that do not provide a tangible economic benefit to farmers and that show a declining population trend. Local farmers with greater species knowledge did not know significantly more than those with less knowledge about the species to be protected, nor did they list more legally protected species. The preliminary assumption of the conservationists was that the locals knew the species and listed the ones to be protected for essentially functional reasons (e.g. usefulness). By contrast, it was found that many more aspects (e.g. population trends, appearance) also had a significant impact. Once the boundaries between the two knowledge systems are removed, collaboration between the stakeholder groups can facilitate the protection of natural assets and local communities. We consider it the responsibility of conservationists (together with ethnoecologists and other researchers) to ensure that these preferences are properly understood for the benefit of conservation and local communities. Read the free Plain Language Summary for this article on the Journal blog.

First direct dating of the Late Neanderthal remains from Subalyuk Cave in Northern Hungary.

The Subalyuk hominin remains were uncovered in 1932 in a cave of the same name in the Bükk Mountains, near the village of Cserépfalu in Borsod-Abaúj-Zemplén County, Northern Hungary. The remains represent two individuals, an adult and a young child who have been described in a few publications since their discovery, providing substantial anthropological data and general assessments of their Neanderthal affiliation. They were associated with Late Mousterian industry. Thus, the Bükk Mountains gain importance in the discussion concerning the contribution of East Central European sites to the debate on the peopling history of Europe during the Late Middle to Early Upper Palaeolithic transition. In this paper, we summarize the archaeological and chronological context of the two individuals, and publish the first direct dating results that place them among the Last Neanderthals of Central Europe.

Re-investigation of fossil Lemmini specimens from the early and Middle Pleistocene of Western and Central Europe: Evolutionary and paleoenvironmental implications

The current study focuses on the emblematic Myopus/Lemmus species complex (tribe Lemmini) in the European Pleistocene fossil record. The members of the two genera occupy distinct ecological niches and have different external appearances, but they are remarkably similar in their dental morphology, so that they were commonly thought of as undistinguishable in the fossil record. Thus, more or less all European Lemmini fossils have been assigned to the genus Lemmus. In the Early Pleistocene site of Schernfeld (Germany), the species Lemmus kowalskii had been described. It was thought by some authors that all Lemmini from Early to late Middle Pleistocene belong to this species.In the current study, we investigated Lemmini molar morphology from Western and Central European sites including Schernfeld (Early Pleistocene), Sackdillinger Höhle (Sackdilling Cave), and Koněprusy C718 (both early Middle Pleistocene), as well as other fossil localities with fewer specimens, formerly assigned to Lemmus kowalskii. Using an extensive modern referential material of Lemmus and Myopus, this study proposes to re-evaluate taxonomic status of the Middle and Early Pleistocene Lemmini. This modern referential also allows a better understanding of the morphology of Lemmus kowalskii specimens and its variability.Our results highlight the very high variation within fossil populations, as well as significant statistical differences between populations of the Early and Middle Pleistocene localities. A large part of these fossil specimens is firmly identified as Myopus sp., including the L. kowalskii holotype. Our identifications demonstrate that in most Early and Middle Pleistocene sites considered in this study, both genera (Lemmus and Myopus) are present. Possible interpretations and consequences for current view of lemming history are discussed, as well as some of the paleoecological and paleoenvironmental implications.

Long term evaluation of factors influencing the association of ixodid ticks with birds in Central Europe, Hungary

Birds play a crucial role in disseminating ticks that carry pathogens of high veterinary-medical importance. The aim of this study was to analyze data of a long-term tick collection from birds at a single stop-over site in Central Europe, Hungary. Over eight years (2015–2022) 5833 ticks (ten species) were collected from 2395 tick-infested birds. The most abundant species were Ixodes ricinus (n = 3971) and Haemaphysalis concinna (n = 1706). Ixodes ricinus nymphs and larvae were the most frequently occurring on resident and short-distance migratory birds with forest habitat but Ha. concinna was the most abundant species on reed-associated, long-distance migrants. Haemaphysalis concinna occurred mostly on birds feeding above the ground level, while I. ricinus predominated on ground feeding birds. Infestation with I. ricinus nymphs always peaked in the first half of the year, in contrast to larvae which were more abundant on avian hosts in the autumn. At the same time, Ha. concinna larvae and nymphs had their peak numbers in the summer. This is the first long-term study on the tick infestation of birds in Central Europe. The study shows that, migration distance, habitat type, and typical feeding level of birds, as well as characteristics of tick life cycle are all key factors in the role of birds as tick disseminators. It was revealed that Savi’s Warbler (Locustella luscinioides) is the most frequent hosts of Ha. concinna in Central Hungary.

Optical properties and simple forcing efficiency of the organic aerosols and black carbon emitted by residential wood burning in rural central Europe

Abstract. Recent years have seen an increase in the use of wood for energy production of over 30 %, and this trend is expected to continue due to the current energy crisis and geopolitical instability. At present, residential wood burning (RWB) is one of the most important sources of organic aerosols (OAs) and black carbon (BC), posing a significant risk to air quality and health. Simultaneously, as a substantial aerosol source, RWB also holds relevance in the context of aerosol radiative effects and climate. While BC is recognized for its large light absorption cross-section, the role of OAs in light absorption is still under evaluation due to their heterogeneous composition and source-dependent optical properties. Existing studies that characterize wood-burning aerosol emissions in Europe primarily concentrate on urban and background sites and focus on BC properties. Despite the significant RWB emissions in rural areas, these locations have received comparatively less attention. The present scenario underscores the imperative for an improved understanding of RWB pollution, aerosol optical properties, and their subsequent connection to climate impacts, particularly in rural areas. We have characterized atmospheric aerosol particles from a central European rural site during wintertime in the village of Retje in Loški Potok, Slovenia, from 1 December 2017 to 7 March 2018. The village experienced extremely high aerosol concentrations produced by RWB and near-ground temperature inversion. The isolated location of the site and the substantial local emissions made it an ideal laboratory-like place for characterizing RWB aerosols with low influence from non-RWB sources under ambient conditions. The mean mass concentrations of OA and BC were 35 µg m−3 (max⁡=270 µg m−3) and 3.1 µg m−3 (max⁡=24 µg m−3), respectively. The mean total particle number concentration (10–600 nm) was 9.9×103 particles cm−3 (max⁡=59×103 particles cm−3). The mean total light absorption coefficients at 370 and 880 nm measured by an AE33 Aethalometer were 120 and 22 Mm−1 and had maximum values of 1100 and 180 Mm−1, respectively. The aerosol concentrations and absorption coefficients measured during the campaign in Loški Potok were significantly larger than reported values for several urban areas in the region with larger populations and a larger extent of aerosol sources. Here, considerable contributions from brown carbon (BrC) to the total light absorption were identified, reaching up to 60 % and 48 % in the near-UV (370 nm) and blue (470 nm) wavelengths. These contributions are up to 3 times higher than values reported for other sites impacted by wood-burning emissions. The calculated mass absorption cross-section and the absorption Ångström exponent for RWB OA were MACOA,370nm=2.4 m2 g−1, and AAEBrC,370-590nm=3.9, respectively. Simple-forcing-efficiency (SFE) calculations were performed as a sensitivity analysis to evaluate the climate impact of the RWB aerosols produced at the study site by integrating the optical properties measured during the campaign. The SFE results show a considerable forcing capacity from the local RWB aerosols, with a high sensitivity to OA absorption properties and a more substantial impact over bright surfaces like snow, typical during the coldest season with higher OA emissions from RWB. Our study's results are highly significant regarding air pollution, optical properties, and climate impact. The findings suggest that there may be an underestimation of RWB emissions in rural Europe and that further investigation is necessary.

A photographic atlas for European freshwater and migratory fish remains and key considerations for their analysis

AbstractIdentification of archeological fish remains requires the use of comparative reference materials, generally in the form of disarticulated fish skeletons. Photographic or illustrative atlases provide an additional resource for the analysis of fish remains. Photographic resources exist for many marine species and for specific geographic regions, whereas freshwater European species have not been covered in great detail. Here, we present a photographic atlas for the bones of freshwater and migratory fish commonly recovered from archeological sites in Central Europe, alongside a discussion of the difficulties and considerations for the analysis of freshwater fish remains. The atlas also highlights the morphological similarity of many species and the interpretive limits of freshwater fish assemblages. The atlas aims to act as an accessible and user‐friendly resource, which can be used for basic identification purposes when access to physical collections is not possible, to supplement pre‐existing collections, or for training purposes. This paper acts as a platform from which the full atlas can be downloaded.

Air-soil cycling of oxygenated, nitrated and parent polycyclic aromatic hydrocarbons in source and receptor areas

Polycyclic aromatic hydrocarbons (PAHs) and their oxygenated and nitrated derivatives, OPAHs and NPAHs, are semivolatile air pollutants which are distributed and cycling regionally. Subsequent to atmospheric deposition to and accumulation in soils they may re-volatilise, a secondary source which is understudied.We studied the direction of air-soil mass exchange fluxes of 12 OPAHs, 17 NPAHs, 25 PAHs and one alkylated PAH in two rural environments being influenced by the pollutant concentrations in soil and air, by season, and by land cover. The OPAHs and NPAHs in samples of topsoil, of ambient air particulate and gas phases and in the gas-phase equilibrated with soil were analysed by GC-APCI-MS/MS. The pollutants soil burdens show a pronounced seasonality, a winter maximum for NPAHs and PAHs and a summer maximum for OPAHs. One order of magnitude more OPAH and parent PAH are found stored in forest soil than in nearby grassland soil. Among a number of 3–4 ring PAHs, the OPAHs benzanthrone and 6H-benzo(c,d)pyren-6-one, and the NPAHs 1- and 2-nitronaphthalene, 9-nitrophenanthrene and 7-nitrobenz(a)anthracene are found to re-volatilise from soils at a rural background site in central Europe in summer. At a receptor site in northern Europe, net deposition of polycyclic aromatic compounds (PACs) prevails and re-volatilisation occurs only sporadic.Re-volatilisation of a number of PACs, including strong mutagens, from soils in summer and even in winter indicates that long-range atmospheric transport of primary PAC emissions from central Europe to receptor areas might be enhanced by secondary emissions from soils.

Positive matrix factorization of seasonally resolved organic aerosol at three different central European background sites based on nuclear magnetic resonance Aerosolomics data

Concentration data derived from 1H NMR analysis of the water-soluble organic compounds from fine aerosol (PM2.5) at three Central European background stations, Košetice, Frýdlant (both in the Czech Republic), and Melpitz (Germany), were used for detailed source apportionment analysis. Two winter and two summer episodes (year 2021) with higher organic concentrations and similar wind directions were selected for NMR analyses. The concentration profiles of 61 water-soluble organic compounds were determined by NMR Aerosolomics and a principal component analysis (PCA) was performed on this dataset. Based on the PCA results, 23 compounds were selected for positive matrix factorization (PMF) analysis in order to identify dominant aerosol sources at rural background sites in Central Europe. Both the PCA and the subsequent PMF analyses clearly distinguished the characteristics of winter and summer aerosol particles.In summer, four factors were identified from PMF and were associated with biogenic aerosol (61–78 %), background aerosol (9–15 %), industrial biomass combustion (7–13 %), and residential heating (5–13 %). In winter, only 3 factors were identified - industrial biomass combustion (33–49 %), residential heating (37–45 %) and a background aerosol (8–30 %). The main difference was observed in the winter season with a stronger contribution of emissions from industrial biomass burning at the Czech stations Košetice and Frýdlant (47–49 %) compared to the Melpitz station (33 %). However, in general, there were negligible differences in identified sources between stations in the given seasons, indicating a certain homogeneity in PM2.5 composition within Central Europe at least during the sampling periods.

Kostenki 4 ground stone tools in the collection of Kunstkamera museum (MAE RAS)

Tools made of soft rock materials at the Upper Paleolithic sites are usually represented by pebbles that were used for various domestic purposes without intentional modification of their shape. In the Neolithic period, the anisotropic stone raw materials were processed for manufacturing tools (such as axes, adzes, chisels, etc.) by abrasion — grinding, cutting edge sharpening, surface polishing. During the Upper Paleolithic, the occurrences of this technology use are rare due to the lesser role of woodworking in the life of glacial hunters. An exception is a series of ground tools from the Pavlovian sites in Central Europe, as well as from a few Gravettian sites similar to them by culture in the Kostenki-Borshchevo locality on the river Don. The largest assemblage of the ground tools originating from the site Kostenki 4 (excavations by A.N. Rogachev in 1937–1938) is housed in MAE RAS. Among these items there are rounded biconvex and plano-convex items (discs), rod-shaped and bullet-shaped items, as well as objects and fragments with polished surfaces and edges. The site comprises materials of a full cycle of manufacturing polished products, including a set of raw materials — quartzite abrasive tiles, pebbles and pieces of slate, dolomite, marl. The major part of collection consist of a series of bifacially treated blanks and amorphous items with the localized grindings. Polished discs and rods stand out for their peculiarity even against the background of the Holocene Stone Age ground tools, remaining beyond typological analogies. The traces of utilization such as short scratches and dints have surface localization instead of cutting edges or tips. The function of these objects as retouchers was determined through a traceological examination by S.A. Semenov. However, the presence of commonly used pebble and flint retouchers in the collection, combined with labor costs during grinding and mass production of such items, leaves the question of their usage open. The article presents a description of polished items from the collection of Kostenki 4, stored in the MAE (Kunstkamera) of the Russian Academy of Sciences, as well as the results of studying the issues of their manufacture and functioning.

A seven-year-based characterization of aerosol light scattering properties at a rural central European site

Our study investigates the temporal variability of aerosol light scattering properties measured at three wavelengths (total scattering coefficient, backscattering coefficient, Ångström scattering exponent, hemispheric backscattering ratio and asymmetry parameter) at the rural background site of the National Atmospheric Observatory Košetice over a period of over seven years (2012–2019). The influence of fog and cloudiness on aerosol light scattering properties (ASP), together with their comparison to particle number size distribution was also investigated. The overall medians of total scattering (σsp) and backscattering coefficient (σbsp), hemispheric backscattering ratio (b) and asymmetry parameter (g) measured at 550 nm and Ångström scattering exponent (SAE_450/700) were 35.20 Mm−1, 5.07 Mm−1, 0.14 and 0.57 and 1.82, respectively. σsp and g decreased by 2.05 Mm−1/year, and 0.009/year, respectively, whereas b increased by 0.004/year. The selected aerosol properties were strongly correlated with particle number, mass, area and volume concentrations in the 200–800 nm mode. A decrease in SAE_450/700 implies a shift towards larger particle sizes, and evolutions in b and g suggest a higher backscattering portion to total scattering. The highest σsp and σbsp levels were observed in the cold seasons together with higher concentrations of air pollutants (carbonaceous aerosol, SO2 and NOx). This could be explained by enhanced emissions from human activities such as domestic heating combined with the higher stability of the atmosphere (poor atmospheric dispersion). In the summer, decreases in particle size and higher rates of backscatter fraction were attributed to secondary organic aerosol (SOA) formation. The accumulation mode showed the strongest aerosol scattering potential, with SAE_450/700 values < 2. Aerosol light scattering was significantly higher during overcast and foggy days compared to fine, cloudy, partly cloudy and no-fog days, possibly due to the particle hygroscopic growth under high relative humidity (shift of particle size towards larger sizes), which in turn can lead to a lower aerosol backscattering fraction. Source identification linked the changes in ASP to the synoptic situation over Europe rather than to specific sources of pollution.

Process-oriented models of autumn leaf phenology: ways to sound calibration and implications of uncertain projections

Abstract. Autumn leaf phenology marks the end of the growing season, during which trees assimilate atmospheric CO2. The length of the growing season is affected by climate change because autumn phenology responds to climatic conditions. Thus, the timing of autumn phenology is often modeled to assess possible climate change effects on future CO2-mitigating capacities and species compositions of forests. Projected trends have been mainly discussed with regards to model performance and climate change scenarios. However, there has been no systematic and thorough evaluation of how performance and projections are affected by the calibration approach. Here, we analyzed &gt;2.3 million performances and 39 million projections across 21 process-oriented models of autumn leaf phenology, 5 optimization algorithms, ≥7 sampling procedures, and 26 climate model chains from two representative concentration pathways. Calibration and validation were based on &gt;45 000 observations for beech, oak, and larch from 500 central European sites each. Phenology models had the largest influence on model performance. The best-performing models were (1) driven by daily temperature, day length, and partly by seasonal temperature or spring leaf phenology; (2) calibrated with the generalized simulated annealing algorithm; and (3) based on systematically balanced or stratified samples. Autumn phenology was projected to shift between −13 and +20 d by 2080–2099 compared to 1980–1999. Climate scenarios and sites explained more than 80 % of the variance in these shifts and thus had an influence 8 to 22 times greater than the phenology models. Warmer climate scenarios and better-performing models predominantly projected larger backward shifts than cooler scenarios and poorer models. Our results justify inferences from comparisons of process-oriented phenology models to phenology-driving processes, and we advocate for species-specific models for such analyses and subsequent projections. For sound calibration, we recommend a combination of cross-validations and independent tests, using randomly selected sites from stratified bins based on mean annual temperature and average autumn phenology, respectively. Poor performance and little influence of phenology models on autumn phenology projections suggest that current models are overlooking relevant drivers. While the uncertain projections indicate an extension of the growing season, further studies are needed to develop models that adequately consider the relevant processes for autumn phenology.

Turkey Oak (Quercus cerris L.) Resilience to Climate Change: Insights from Coppice Forests in Southern and Central Europe

Turkey oak (Quercus cerris L.) is a thermophilic oak species that is gaining importance in the context of ongoing climate change because of its better resistance to climatic extremes and drier conditions. Therefore, this article focuses on Turkey oak’s role and growth properties in the coppice forests of Southern Europe (Italy, Bulgaria) compared to similar site conditions in Central Europe (Slovakia, Czechia). The aims are to evaluate the basic dendrometry indicators, stand biodiversity, growth dynamics, and the effect of climatic factors on tree-ring increment on specific site chronologies. We found that the tree density in coppices of 50–60 years varied between 475 and 775 trees ha−1, and the stand volume ranged from 141 to 407 m3 ha−1. The complex stand diversity of all plots ranged from a monotonous to uniform structure. The size of tree-ring growth was closely related to indicators of stand density. The lowest influence of climatic factors on tree-ring growth was found in sites in Italy and the highest in Slovakia. The primary limiting factor for growth was the lack of precipitation during the growing season, especially in June and July. In contrast, temperature had a marginal effect on radial growth compared to precipitation. The radial growth in research plots in Southern Europe goes through longer 6 to 8-year growth cycles, and in Central European sites, it goes through shorter cycles of 2.4 to 4.8 years, which confirms better growth conditions in this region. The studied coppice stands exhibit a stable reaction to climate change. Yet, regarding cyclical growth, the Central European stands benefit from an advantageous climate and grow better than in Southern Europe. As part of the changing environmental conditions, Turkey oak is becoming an important tree species that can achieve high production potential even in drier habitats due to its regeneration characteristic as coppice and may play a critical role in its northerly introduction in Europe.

New insights into Magdalenian subsistence at Petersfels (Hegau Jura, southwestern Germany)

At Petersfels (Hegau Jura, southwestern Germany), one of the most prolific Magdalenian sites in Central Europe, nearly one hundred years of excavation and research has revealed an exceptional record of human occupation from 15,000 years ago. Unstudied faunal remains (n = 3256) from a 16 m2 area in front of the cave (P6 excavation area) provide an opportunity to assess the site from a modern perspective. Reindeer (Rangifer tarandus) dominate the assemblage followed by hare (Lepus sp.), horse (Equus ferus), and ptarmigan (Lagopus sp.). The faunal remains are well-preserved and exhibit abundant cut marks, impacts, and green breaks, attesting to the highly anthropogenic nature of the assemblage. Carnivore damage is also present, although to a lesser extent, and suggests that fox- and wolf-sized carnivores gained secondary access by exploiting human garbage. Evidence for the transport of reindeer limbs, osseous artifacts, and other remnants of material culture indicates hunter-gatherers used P6 for habitation and the secondary processing of faunal remains, especially butchery, marrow extraction, and tool production. Overall, our results support prior interpretations of the site as a fall-winter aggregation camp and provide new information on human subsistence practices, the role of carnivores, and the use of space by Magdalenian people.

Electrochemical Approximation to Bronze Age Chronology via Multiple Scan Voltammetry.

Insert A multiple-scan voltammetry strategy is described and applied to a set of 107 Bronze Age and later copper/bronze objects, mainly from sites in Central Europe. This methodology allows the study of the compositional and textural properties (compactness, crystallinity, degree of hydration) of the patina to be studied from the accumulated peak current values for the characteristic signals corresponding to the reduction of cuprite and tenorite to metallic copper. A new model for the relationship between peak current and the depth reached in successive scans is presented and used to discriminate samples of different provenance and manufacturing technique, as well as their ascription to different Bronze Age periods.

Genetic diversity and population structure of the endangered Rubus chamaemorus populations in Poland

Rubus chamaemorus in Europe is currently only found in scattered sites in Central Europe, mainly in mountainous areas but also in lowlands, probably reflecting its relict nature. Unfortunately, so far, there is little information on the genetic diversity of R. chamaemorus populations in Central Europe. Therefore, in this study, we used genetic markers to investigate variation in 21 of its European populations. Using a Bayesian approach, STRUCTURE software analysis was applied to the six clusters that best represented the genetic structure of the cloudberry populations. The results indicated the presence of low genetic diversity between populations in geographical groups, but high diversity between geographical regions. These results were somewhat predictable because the vast lowlands that separate the mountains in Poland from the population of R. chamaemorus in the north are a significant geographical barrier to gene flow over long geographical distances. Isolation by distance may also explain the genetic distinctness between populations found in the various regions in Poland and populations found in Scandinavia. It is likely that there is a genetic melting pot for R. chamaemorus in the region of northern Poland. This is often the case in small areas where populations from different geographic regions meet. It is often difficult to indicate the migration routes of species and to confirm where individual populations come from, but their occurrence is favored by isolation in mountain valleys and in forests, which are a barrier to the spread of pollen.

Local site conditions reduce interspecific differences in climate sensitivity between native and non-native pines

Two European pine species, Pinus sylvestris and Pinus nigra, are experiencing dieback as a result of the increasing frequency and intensity of extreme climatic events. Recent species distribution models predicted shrinkage of ecological niches in the near future and shifted their habitat range towards the northeast. Consequently, P. sylvestris may contract its range and P. nigra may expand in Central Europe. To test whether native pine species have an advantage over introduced pine species in acclimation to a novel climate in Central Europe, we investigated the climate sensitivity and vitality of P. sylvestris, P. nigra and P. rigida. We sampled mature stands of each pine species at three sites in Central Europe, for which we determined climate–growth relationships: temporal stability of temperature and precipitation correlations with tree-ring width and resilience indices. Based on remote sensing data, we assessed differences in surface reflectance and photosynthetic activity obtained from the normalised difference vegetation index (NDVI). Our analyses revealed that the climate sensitivity and surface reflectance of pines are not due to their nativeness in Central Europe but better explained by local site conditions. The specificity and variability of drought events may determine both the homogeneous and diverse susceptibility of species to a negative water balance. Therefore, the character of future climatic extremes seems to be the key to understanding the acclimation of native and non-native pine species in Central Europe. Because our study do not provide evidence of the superiority of non-native pine species over P. sylvestris, and the potential impacts of introduced species on local habitats seem poorly understood in the face of climate change, we urge particular caution in introducing species with unrecognized invasive potential.