Southwest Germany Research Articles

Differentiation between Galium album and Galium mollugo in southwest Germany

Für die Unterscheidung der sehr ähnlichen Arten Galium album Mill. (tetraploid) und Galium mollugo L. (diploid; Rubiaceae) werden zum Teil widersprüchliche Angaben zu den Differenzialmerkmalen gegeben. Daher sollen in dieser Arbeit Merkmale herausgearbeitet werden, die sich für eine eindeutige Unterscheidung im Feld und generell eignen. An südwestdeutschen Proben beider Arten wurden zunächst genetische und anschließend morphologische Merkmale wie Blütendurchmesser, Blütenstiellänge, Strukturdicke im Blattquerschnitt, Blattlänge und -breite untersucht. Für die Bestimmung der Ploidiestufe wurden Zellkerngrößen ermittelt. Hinsichtlich der Zellkerngrößen unterscheiden sich die beiden Arten deutlich. Die Sequenzierung einiger DNA-Marker ergab keine Trennung der beiden Arten. Morphologisch lässt sich Galium album von G. mollugo am besten durch den größeren Blütendurchmesser, die größere Blattlänge und -breite sowie das höhere Verhältnis von Blattlänge zu -breite unterscheiden. Auf der Grundlage der gefundenen Merkmale wurde ein Vorschlag für einen neuen Bestimmungsschlüssel erstellt.

Plant exchange networks in the 19th century – 200 years of citizen science

Plant exchange networks in the 19th century have been investigated in a largescale study, firstly by identifying as many plant exchange organizations (PEOs) as possible and secondly by searching for exchange partners in a 19th century private herbarium from Southwest Germany, and by analysing exchange activities related to the rare central European endemic Saxifraga rosacea subsp. sponhemica (C.C.Gmel) D.A.Webb. In this paper a first overview on selected results is given: 101 PEOs – founded from 1819 to 1947 – with a total of 3000 to 5000 members have been found; they distributed 15 to 20 million specimens; 111 collectors have been identified in the exemplary private herbarium, from which specimens have been found in 27 herbaria; S. rosacea subsp. sponhemica has been collected by 242 individuals, 233 exchange partners received duplicates distributed by 12 PEOs.

Community Size and Electoral Preferences: Evidence From Post-Second World War Baden-Württemberg

Abstract We examine whether electoral preferences depend on a community's population size by studying post-Second World War Baden-Württemberg in Southwest Germany. Our identification strategy exploits the fact that the French administration zone prohibited German expellees from entering, contrary to the contiguous American zone. Population size positively predicts voting for the Social Democrats (the party advocating substantial government involvement in practically all domains) and negatively for the Christian Democrats (the small-government party advocating free-market policies). Results are neither driven by pre-existing voting patterns, religious compositions, and location- and time-specific unobservables, nor other measurable cultural, demographic, economic, or political characteristics. Alternative explanations pertaining to expellee voting behaviour or a backlash of natives against expellees appear unlikely – population size prevails as a predominant voting predictor.

Description of box trapping, immobilisation, anaesthesia monitoring and blood chemistry and serology in free-ranging European wildcats (Felis silvestris) in Southwest Germany

Specific questions in wildlife research and surveillance require safe and efficient capture, handling and anaesthesia protocols to enable sampling and transmitter placement in free-ranging individuals. For wild felids, various protocols are available, but detailed reports for European wildcats (Felis silvestris) are scarce. In particular, tools for anaesthesia monitoring under field conditions and reference values for heart rate, respiratory rate, oxygen saturation and body temperature are missing. In the present study, European wildcats were caught in box traps before being released into catch bags for manual restraint. Inside the bags, ketamine-xylazine anaesthesia was applied via intramuscular injection, adjusted to the animal’s body weight. During anaesthesia, samples were taken, and vital variables were monitored continuously. Haematology and blood chemistry parameters were obtained, along with serological markers for antibodies against feline immunodeficiency virus (FIV), feline coronavirus and antigens of feline leukaemia virus (FeLV). In total, 29 wildcats were captured, of which 21 were examined and marked with passive integrated transponders. Twelve wildcats were collared with GPS transmitters. Handling time under anaesthesia averaged 30 min (range 26–35 min). Heart rate ranged between 76 and 170 beats/min and respiratory rate between 20 and 52 breaths/min. Relative arterial oxygen saturation stayed mainly between 93 and 99%, and rectal temperature ranged between 36.2 and 40.2 °C. Further, FeLV antibodies were detected in 2/21 samples. The applied protocol facilitated safe and sufficient examination, sampling and transmitter placement, as well as the establishment of haematological and blood chemical values in free-ranging European wildcats for the first time.

Experimental Reconstructions of the Mammoth Ivory Flute from Geißenklösterle Cave (GK3) and Other Palaeolithic Wind Instruments from South-West Germany

Experimental Reconstructions of the Mammoth Ivory Flute from Geißenklösterle Cave (GK3) and Other Palaeolithic Wind Instruments from South-West Germany

On-farm use of recycled liquid ammonium sulphate in Southwest Germany using a participatory approach

AbstractFor political and environmental reasons, there is an urgent need for alternatives to energy-intensive synthetic fertilizers. One solution is the targeted recycling of nutrients within agriculture. In this study, liquid ammonium sulphate (LAS) as a recycling product derived from digestate treatment was compared to calcium ammonium nitrate, manure and original digestates in an on-farm experiment using a participatory approach. Based on regular meetings with the farmers involved, a flexible experimental design was developed which integrated the fertilization legislation and the farmers’ operational structures already in place, such as crop rotation, available application techniques and manure management demands. The aim was to achieve both implementation practicability and acceptance of the study results by the farmers. Results from the year 2020 showed that LAS applied with three-jet nozzles in barley and wheat had significantly lower yields than the other fertilizers. Applied with a slurry tanker trailing shoe applicator in 2021, LAS had comparable yields to the other fertilizers in maize (51.2 t ha−1) and comparable yields to digestate in rapeseed (4.4 t ha−1). Application techniques that minimize environmental impacts and lower the LAS pH could potentially increase the effectiveness of the fertilizer. We recommend that farmers use this fertilizer not as a single solution but as a mineral compensatory fertilizer in addition to organic fertilizers following local fertilizer legislation. In this case, LAS could potentially substitute calcium ammonium nitrate (CAN).

High-resolution regional vegetation analyses for Eocene records on the Sprendlinger Horst in Southwest Germany

High-resolution regional vegetation analyses for Eocene records on the Sprendlinger Horst in Southwest Germany

Energy yield decline of Sida hermaphrodita harvested for biogas production

The perennial and herbaceous plant Sida hermaphrodita L. Rusby (Sida) has been investigated intensively with respect to its use as a solid biofuel for combustion and, to a lesser extent, for continuous biogas production. Since biogas production provides many opportunities for economic farm diversification, this study compared the biogas potential of Sida with common biogas crops silage maize (Zea mays L.) and cup plant (Silphium perfoliatum L.). To this end biomass samples were collected from a randomized field trial in Southwest Germany during the vegetative stage in five consecutive years starting in 2014. Biogas batchtests revealed constant specific-methane yields of 279 ± 8 LN kgVS−1 for Sida, significantly lower than for maize (335 ± 5 LN kgVS−1) and significantly higher than for cup plant (264.3 ± 3.7 LN kgVS−1). The annual Sida dry matter biomass yields declined significantly by 51% from 2015 (18.2 ± 2.6 Mg ha−1) to 2018 (9.2 ± 4.8 Mg ha−1) as a result of the summer harvest regime. This, in turn, led to a significant decline in Sida's total annual energy yields. Consequently, the average annual Sida energy yield (3549 ± 901 L heating oil equivalents (HOE) ha−1) was significantly lower than for maize (6611 ± 1186 L HOE ha−1) and cup plant (5261 ± 974 L HOE ha−1). These results clearly indicate that harvesting Sida during the vegetative stage for biogas production significantly decreases its energy yield over time. Therefore, Sida can be used economically and ecologically more sustainable for combustion using the dead plant biomass harvested in winter, while cup plant proved competitive to maize for biogas production.

Using geometric wing morphometrics to distinguish Aedes japonicus japonicus and Aedes koreicus

BackgroundAedes japonicus japonicus (Theobald, 1901) and Aedes koreicus (Edwards, 1917) have rapidly spread in Europe over the last decades. Both species are very closely related and occur in sympatry. Females and males are difficult to distinguish. However, the accurate species discrimination is important as both species may differ in their vectorial capacity and spreading behaviour. In this study, we assessed the potential of geometric wing morphometrics as alternative to distinguish the two species.MethodsA total of 147 Ae. j. japonicus specimens (77 females and 70 males) and 124 Ae. koreicus specimens (67 females and 57 males) were collected in southwest Germany. The left wing of each specimen was removed, mounted and photographed. The coordinates of 18 landmarks on the vein crosses were digitalised by a single observer. The resulting two-dimensional dataset was used to analyse the differences in the wing size (i.e. centroid size) and wing shape between Ae. j. japonicus and Ae. koreicus using geometric morphometrics. To analyse the reproducibility of the analysis, the landmark collection was repeated for 20 specimens per sex and species by two additional observers.ResultsThe wing size in female Ae. koreicus was significantly greater than in Ae. j. japonicus but did not differ significantly for males. However, the strong overlap in wing size also for the females would not allow to discriminate the two species. In contrast, the wing shape clustering was species specific and a leave-one-out validation resulted in a reclassification accuracy of 96.5% for the females and 91.3% for the males. The data collected by different observers resulted in a similar accuracy, indicating a low observer bias for the landmark collection.ConclusionsGeometric wing morphometrics provide a reliable and robust tool to distinguish female and male specimens of Ae. j. japonicus and Ae. koreicus.Graphical

Simulation of ground motion emissions from wind turbines in low mountain ranges: implications for amplitude decay prediction

The characterization and prediction of wind turbine (WT) emissions are important steps in reducing their impact on humans or sensitive technologies such as seismic stations or physics experiments. Here, WT ground motion emissions are studied along two measurement lines set up at two wind farms on the Eastern Swabian Alb, southwest Germany. The main purpose of the data analysis is to estimate amplitude decay rates from vertical component data and surface wave phase velocities excited by the permanent motion of the WT towers. Phase velocities as well as geological information serve as input to build realistic subsurface models for numerical wave field simulations. Amplitude A decay rates are characterized by b-values through Asim 1/r^b depending on distance r and are derived from peaks in power spectral density (PSD). We find an increase of b_text {PSD} with frequency from 0.5 to 3.2 for field data. For low frequencies (1.2 Hz and 3.6 Hz), b_text {PSD} ranges from 0.5 to 1.1, hence close to the geometrical spreading factor of surface waves (b_text {PSD}=1). Anelastic damping and scattering seem not to be significant at these frequencies which also shows in numerical simulations for quality factors Q=50-200. We also find that the emitted wavefields from several WTs interfere, especially in the near-field, and produce strong local ground motion amplitudes. The inclusion of a steep topography present in low mountain ranges adds more wave field distortions which can further increase the amplitudes. This needs to be considered when predicting WT induced ground motions.

Impact of different establishment methods for summer-sown cover crops in Southwestern Germany on their weed suppression properties

Early establishment of cover crops (CCs) is essential for attaining successful weed suppression in the autumn-to-spring period. Due to reduced precipitation and extended periods of drought in the summer within temperate zones, the establishment of CCs poses challenges. Three methods of cover crop (CC) establishment were tested: 1) preharvest sowing 10 days before harvest of cash crop (PreHa); 2) no-till sowing directly after harvest of cash crop (NoTi) and 3) sowing with reduced tillage 10 days after harvest of cash crop (ReTi). The five CC species black oat (Avena strigosa Schreb.); common buckwheat (Fagopyrum esculentum Moench), phacelia (Phacelia tanacetifolia Benth.), fodder radish (Raphanus sativus var. oleiformis L.) and common vetch (Vicia sativa L.), along with a mixture comprising 20% of all five species, were included as second factor in a three-year field experiment (2020–2022) conducted in South West Germany. One treatment per establishment method was maintained without CCs as a control. Measurements of CC, volunteer cereal and weed density, soil coverage, and dry matter were carried out throughout the autumn-to-late autumn timeframe. On average across all years and CCs, the PreHa and NoTi establishment demonstrated the highest CC dry matter contents of 99 g m−2 and 119 g m−2, respectively, despite lower CC densities. This had a particularly notable impact on weed density in the ReTi variant, which, over the three-year average across all CC treatments, was 5 times higher than in NoTi and PreHa but exhibited a 18–27% smaller volunteer cereal density by comparison, thereby influencing the respective volunteer cereal and weed coverages. Meanwhile, weed and volunteer cereal dry matters were consistent across all establishment methods. The CC mixture exhibited enhanced resilience to fluctuating weather conditions, leading to an overall superior performance across the three-year experimental period and showing highest measured CC dry matters up to 272 g m−2 in 2022. However, the observed effects in the treatments varied considerably depending on the CC species, sowing date, and weather conditions. In summary, this study demonstrates that early CC sowing, whether directly after the cash crop harvest or 10 days before the cash crop is harvested, has a positive impact on CC biomass formation, especially leading to a reduced weed emergence. Additionally, under variable weather conditions, a diverse CC mixture can exhibit a more stable overall performance compared to CC monocultures.

Declining populations of Astacus astacus drag European Branchiobdella parasita (Annelida: Clitellata) ectosymbionts to serious biodiversity loss

Branchiobdella parasita is specific ectosymbiont of European freshwater crayfish, including endangered noble crayfish (Astacus astacus). Although numerous information on distribution, biology or ecology were reported, genetic structure of B. parasita in European crayfish populations was not studied truthfully. The available molecular data include only cytochrome oxidase subunit I (COI) barcodes of B. parasita coexisting with noble crayfish in Alpine freshwaters in Austria, as well as stone crayfish (Austropotamobius torrentium) and white-clawed crayfish (Austropotamobius pallipes) in Balkan region. Here we report first genetic diversity and haplotype richness analysis of B. parasita populations on a pan-European scale. Specimens (n = 41) were collected from female noble crayfish from three lakes in northwest Poland (Kołtki Małe, Rosko Duże, Skrzynki Małe) and Elkenrother Weiher Lake in southwest Germany, high-quality COI barcodes were obtained and analysed against existing genetic data. The analysed populations were haplotype rich (h = 23) and had high COI haplotype diversity (Hd = 0.8988, I = 1.4554). Our results indicate that diversification rate of European B. parasita populations highly depends on habitat quality, its connection with surface waters and hosts species and mobility. We revealed that Central European populations inhabiting noble crayfish show significant genetic relationship, presenting common ancestral haplotypes and at the same time high genetic divergence from Balkan populations. Based on our results we suggest that ‘parasita-complex’ of phylogenetically related species with similar body shape and structure of chitin jaws, but with differentiating anatomical structure details are present across the continent.

A new eryopid temnospondyl from the Carboniferous–Permian boundary of Germany

AbstractA new eryopid temnospondyl, Stenokranio boldi n. gen. n. sp. is described based on well-preserved cranial and postcranial material from fluvio-lacustrine deposits of the Permo-Carboniferous (Gzhelian/Asselian) Remigiusberg Formation at the Remigiusberg quarry near Kusel, Saar–Nahe Basin, southwest Germany. The new taxon is characterized by three autapomorphies within the Eryopidae: (1) the relatively narrow posterior skull table, therefore nearly parallel lateral margins of the skull; (2) the short postparietals and tabulars; and (3) the wide ectopterygoid. Phylogenetic analysis reveals a monophyletic Eryopidae with the basal taxa Osteophorus, Glaukerpeton, and Onchiodon labyrinthicus forming a polytomy. Actinodon may be either a basal eryopid or a stereospondylomorph, and the genus Onchiodon is not monophyletic. Stenokranio n. gen. is found as a more derived eryopid forming the sister taxon to Eryops. Stenokranio n. gen. was among the largest predators of the Saar–Nahe Basin. Its semiaquatic lifestyle enabled Stenokranio n. gen. to browse riverbanks and lake shorelines for prey, but most likely it fed on aquatic vertebrates. Stenokranio n. gen. was part of a faunal assemblage of aquatic, semiaquatic, and fully terrestrial vertebrates, such as sarcopterygian and actinopterygian fishes, xenacanthid sharks, a dvinosaurian temnospondyl, different “lepospondyls”, diadectomorphs, and synapsids. This is in general accordance with the vertebrate community from the Permo-Carboniferous of North America and from the early Permian localities of Manebach (Thuringian Forest Basin) and Niederhäslich (Döhlen Basin). It is notable that the occurrence of Stenokranio n. gen. and other eryopids in these localities excluded the presence of other large temnospondyls such as Sclerocephalus. However, a previously described isolated eryopid mandible from the Remigiusberg locality differs from that of Stenokranio n. gen. in several characters, implying that probably two different eryopid taxa lived at the same locality.UUID: www.zoobank.org/88a52547-d6fc-40af-965c-a6786c252ed5

Agrivoltaics mitigate drought effects in winter wheat.

Climate change is expected to decrease water availability in many agricultural production areas around the globe. At the same time renewable energy concepts such as agrivoltaics (AV) are necessary to manage the energy transition. Several studies showed that evapotranspiration can be reduced in AV systems, resulting in increased water availability for crops. However, effects on crop performance and productivity remain unclear to date. Carbon-13 isotopic composition (δ13 C and discrimination against carbon-13) can be used as a proxy for the effects of water availability on plant performance, integrating crop responses over the entire growing season. The aim of this study was to assess these effects via carbon isotopic composition in grains, as well as grain yield of winter wheat in an AV system in southwest Germany. Crops were cultivated over four seasons from 2016-2020 in the AV system and on an unshaded adjacent reference (REF) site. Across all seasons, average grain yield did not significantly differ between AV and REF (4.7 vs 5.2 t ha-1 ), with higher interannual yield stability in the AV system. However, δ13 C as well as carbon-13 isotope discrimination differed significantly across the seasons by 1‰ (AV: -29.0‰ vs REF: -28.0‰ and AV: 21.6‰ vs REF: 20.6‰) between the AV system and the REF site. These drought mitigation effects as indicated by the results of this study will become crucial for the resilience of agricultural production in the near future when drought events will become significantly more frequent and severe.

Determinants of implementing the ID ROLL OUT study's interventions: qualitative results

Abstract Issue Antimicrobial stewardship programmes (ASP) and infectious disease (ID) specialists aim to ensure the rational use of antimicrobials and to improve patient outcomes. Whilst ASPs are established to varying degrees, ID specialists are rarely available in secondary and tertiary care hospitals in Germany. Description of the problem With the ID ROLL OUT study, we implemented and evaluated an intervention, which comprises ASP with and without ID specialists’ consultation in ten hospitals (excl. university hospitals) in south-west Germany. Little has been reported on the medical and pharmaceutical staff's perspectives on the implementations. This study describes barriers, facilitators, and suggestions for improvement to successfully establish a large-scale multicentre intervention. The participants responsible for implementing the intervention were interviewed using semi-structured, guided interviews at two time-points (t1: n = 17; t2: n = 18). The recorded interviews were analysed for content, following Kuckartz. Results A high level of acceptance and a positive attitude towards the intervention are conducive to the intervention's successful implementation. The teams find extra time for the study and a close staff collaboration at a local team level to be helpful. The main barriers identified are a high workload, lack of acceptance by colleagues in key roles, and the Covid-19 pandemic. Lack of digitalisation and entrenched internal structures were identified as major barriers. To further improve implementation, more infectious disease training should be provided, along with support from superiors and extension of the intervention phase. Moreover, government-mandated ASP guidelines and quality management by the German Medical Association are desired and expected to contribute in the future. Lessons The identified determinants provide much-needed key information, which is important for the efficient, targeted and successful implementation of future similar interventions. Key messages • Acceptance, positive attitude and staff collaboration help to implement the intervention. • Heavy workloads and lack of support from key colleagues hinder the intervention’s implementation.

A new giant nautilid species from the Middle Jurassic of Luxembourg and Southwest Germany

In comparison to other cephalopods such as ammonites and belemnites, nautilid shells are relatively rare fossils in Jurassic marine deposits and knowledge of their taxonomy is therefore still patchy. We describe herein a new species of Cenoceras, C. rumelangense, from the early Bajocian Humphriesianum Zone of Luxembourg and Southwest Germany. In Luxembourg, the type material occurs in the ‘Marnes sableuses d’Audun-le-Tiche’ unit, which yields other large-sized cephalopods, such as the largest known belemnite genus, Megateuthis. The new species reaches a remarkable size, with diameters up to 610 mm. Thus, it is amongst the largest known post-Triassic nautilids worldwide, together with Paracenoceras giganteum and Paracenoceras ingens from the Upper Jurassic. Additionally, we discuss some aspects of the taphonomy of these large shells deposited in a shallow marine setting.

Spotting ethylene in forest soils—What influences the occurrence of the phytohormone?

AbstractDue to the rapid microbial degradation, ethylene (ethene; C2H4) detection in most soils is difficult. The knowledge about factors favoring the occurrence of C2H4 is mainly based on laboratory experiments which are not necessarily representative for real field conditions in forest soils. We report results from a total of 24 measuring plots in southwest Germany and more than 50,000 gas samples, including long-term forest monitoring sites and other study sites involving liming, artificial soil compaction, and temporary waterlogging. Many of the patterns and influencing factors identified in the laboratory were confirmed. In well-aerated forest soils, C2H4 was detected in 1.3% of the gas samples. C2H4 detection was higher at oxygen (O2) concentrations below 10% in the soil. The effect was positively correlated with bulk density in compacted soils and CO2, CH4, and N2O concentrations—factors that indicate reduced microbial activity and thus also facilitate the detection of C2H4. It could be detected 3.5 times more often in spruce than in beech stands, indicating that plant species plays a role and was not found to follow any distinct spatial or temporal pattern with the exception of seemingly random spatio-temporal clusters of root-born C2H4 near large roots of spruce trees. The long observation period and large dataset of this field study allowed valuable insights into C2H4 occurrence in forest soils under natural conditions supporting the theory that the plant hormone C2H4 is produced as a warning for anaerobic soil areas that are limiting root growth.

Type of Refugee Accommodation and Health of Residents: A Cross-Sectional, Population-Based Cluster Analysis in South-West Germany.

Objectives: Few studies have assessed whether refugees' health is associated with accommodation characteristics. We aimed to devise a typology of refugee accommodation based on variables on the accommodation and its physical context before assessing its association with health in multivariate analyses. Methods: We performed a cluster analysis based on a hierarchal, agglomerative clustering algorithm using Euclidean Distance and Ward's method. We analysed accommodation clusters based on number of inhabitants, degree of housing deterioration, urbanity of location (urban/rural distinction), and remoteness (walking distance to shops, medical or administrative services). In total, we analysed health and accommodation data of 412 refugees and asylum seekers from 58 different accommodation facilities in the federal state of Baden-Württemberg in the south-west of Germany. Results: Accommodations with a moderate occupation, lowest levels of deterioration, and a central urban location showed the best health outcomes in terms of subjective general health status, depression, and generalized anxiety disorder (GAD). Associations were strongest for GAD and weakest for depression. Conclusion: Our findings inform policymakers on layout and location of refugee collective accommodation centres.

Production of perfluoroalkyl acids (PFAAs) from precursors in contaminated agricultural soils: Batch and leaching experiments

Contamination of soils with per- and polyfluoroalkyl substances (PFAS) (e.g., aqueous film forming foams (AFFFs) or PFAS containing biosolids applied to agricultural soils) can lead to large scale groundwater pollution. For site management, knowledge about the extent and time scales of PFAS contamination is crucial. At such sites, often persistent perfluoroalkyl acids (PFAAs) and so-called precursors, which can be transformed into PFAAs, co-occur. In this study, the release of PFAAs from 14 soil samples from an agricultural site in southwest Germany contaminated via compost/paper sludge was investigated. Rapid leaching of C4-C8 perfluoroalkyl carboxylic acids (PFCA) was observed in saturated column tests, while slowing down with increasing chain-length (≥ C9 PFCAs). Two selected samples were further incubated in batch-tests after removal of existing C4-C8 PFCAs in extensive column leaching tests until a liquid-solid ratio of 10 l/kg. During 60 days of incubation, aqueous concentrations of C4-C8 PFCAs increased linearly by a factor of 29–222, indicating continuous production by transformation of precursors.The potential PFAA-precursor reservoir was estimated by the direct total oxidizable precursor (dTOP) assay. PFCA concentrations after the dTOP increased up to two orders of magnitude. Production rates determined in batch-tests combined with the results of dTOP assay were used to estimate time scales for the duration of C4-C8 PFCAs emission from the contaminated agricultural soils which likely will last for several decades.

Heat Treatment of Chert in the Early Mesolithic at Rottenburg-Siebenlinden (Southwest Germany)

ABSTRACT Unambiguous evidence for heat treatment in the Early Mesolithic of Southwestern Germany is thus far restricted to one type of raw material and to cave sites of the Swabian Jura region. At the open-air site Rottenburg-Siebenlinden, heat treatment of an additional raw material was proposed. In this paper, we reexamine the lithic assemblage of horizon III, using the best available criterion for recognizing heat treatment: gloss contrast. Through technological analysis of these diagnostic artefacts, we investigate the timing of heat treatment within the reduction sequence. Visual identifications were substantiated by analyzing surface roughness of gloss contrast artefacts. Our results show that heat treatment was regularly applied to a wider range of raw materials than previously thought, during blank production. These findings highlight that the last Central European hunter-gatherers were flexible in terms of material choices and that heat treatment was a more widespread phenomenon than previously thought.