ALBERT

Description: Albedo – the reflectivity of a surface - is an important component in the energy budget, impacting the local to global climate. Data from nadir-viewing satellites can be combined with bidirectional reflectance distribution function (BRDF) data from multi-angular observation platforms to achieve realistic albedo values that acknowledge anisotropy. In my thesis, I evaluated how the land surface albedo varied on spatial and temporal scales during the snow-free period on Disko Island, Greenland. I examined how the albedo differed among the vegetation classes. Concerning the methodology, I assessed how the combination of MODIS BRDF data with Landsat 8 (L8) or Sentinel-2 (S2) influenced the albedo. The study area was located at the southern tip of Disko Island (69.27 °N, -53.47 °E) in West Greenland and covered a wetland and a range of tundra vegetation. I analysed automatic weather station (AWS) data from 2013 to 2022 and conducted mobile albedo measurements in August and September 2022 to examine the temporal and spatial variability. For the period from June to September 2022, I derived the L8 and S2 based albedo with inclusion of MODIS BRDF and narrow to broadband conversion and analysed their variability with regard to vegetation classes. In the snow-free period, the albedo increased from a monthly mean of 0.16 in June to 0.19 in September in the AWS data. The mobile measurements ranged from 〈 0.10 above bare soil and water to 〉 0.23 above areas dominated by lichen, Salix glauca or Equisetum arvense. The satellite-based albedo revealed temporally variable, significant correlations to normalised difference vegetation and moisture indices that reached values 〉 0.5 in the fen and wet heath class on several days. The albedo of shrubs was not notably smaller than other vegetation types but partly 0.01-0.05 above them in both the mobile measurements and the satellite-derived albedo. This finding challenges the assumption that shrubification causes climate forcing in all circumstances. The albedo of L8 and S2 differed to each other and the local data (root-mean-square error 0.04-0.14). The BRDF correction increased the albedo by 0.01 on average compared to nadir reflectance. L8 was better in reproducing the expected temporal and spatial variability of albedo than S2, which displayed less variability. S2 seemed to be more sensitive to atmospheric effects of haze and clouds influencing albedo. Thus, L8 seemed more suitable to calculate albedo in the study area. Though there were some methodological limitations, this thesis highlights aspects that should be considered when analysing albedo or jointly using L8 and S2 in high latitude regions.

Description: Previous field studies in the Southern Ocean (SO) indicated an increased occurrence and dominance of cryptophytes over diatoms due to climate change. To gain a better mechanistic understanding of how the two ecologically important SO phytoplankton groups cope with ocean acidification (OA) and iron (Fe) availability, we chose two common representatives of Antarctic waters, the cryptophyte Geminigera cryophila and the diatom Pseudo-nitzschia subcurvata. Both species were grown at 2°C under different pCO2 (400 vs. 900 μatm) and Fe (0.6 vs. 1.2 nM) conditions. For P. subcurvata, an additional high pCO2 level was applied (1400 μatm). At ambient pCO2 under low Fe supply, growth of G. cryophila almost stopped while it remained unaffected in P. subcurvata. Under high Fe conditions, OA was not beneficial for P. subcurvata, but stimulated growth and carbon production of G. cryophila. Under low Fe supply, P. subcurvata coped much better with OA than the cryptophyte, but invested more energy into photoacclimation. Our study reveals that Fe limitation was detrimental for the growth of G. cryophila and suppressed the positive OA effect. The diatom was efficient in coping with low Fe, but was stressed by OA while both factors together strongly impacted its growth. The distinct physiological response of both species to OA and Fe limitation explains their occurrence in the field. Based on our results, Fe availability is an important modulator of OA effects on SO phytoplankton, with different implications on the occurrence of cryptophytes and diatoms in the future.

Description: The SUMup database is a compilation of surface mass balance (SMB), subsurface temperature and density measurements from the Greenland and Antarctic ice sheets. This 2023 release contains 4 490 442 data points: 1 778 540 SMB measurements, 2 706 413 density measurements and 5 489 subsurface temperature measurements. This is respectively 1 477 132, 420 825 and 4 715 additional observations of SMB, density and temperature compared to the 2022 release. This new release provides not only snow accumulation on ice sheets, like its predecessors, but all types of SMB measurements, including from ablation areas. On the other hand, snow depth on sea ice is discontinued, but can still be found in the previous releases. The data files are provided in both CSV and NetCDF format and contain, for each measurement, the following metadata: latitude, longitude, elevation, timestamp, method, reference of the data source and, when applicable, the name of the measurement group it belongs to (core name for SMB, profile name for density, station name for temperature). Data users are encouraged to cite all the original data sources that are being used. Issues about this release as well as suggestions of datasets to be added in next releases can be done on a dedicated user forum: https://github.com/SUMup-database/SUMup-data-suggestion/issues. Example scripts to use the SUMup 2023 files are made available on our script repository: https://github.com/SUMup-database/SUMup-example-scripts.

Description: The SUMup database is a compilation of surface mass balance (SMB), subsurface temperature and density measurements from the Greenland and Antarctic ice sheets. This 2023 release contains 4 490 442 data points: 1 778 540 SMB measurements, 2 706 413 density measurements and 5 489 subsurface temperature measurements. This is respectively 1 477 132, 420 825 and 4 715 additional observations of SMB, density and temperature compared to the 2022 release. This new release provides not only snow accumulation on ice sheets, like its predecessors, but all types of SMB measurements, including from ablation areas. On the other hand, snow depth on sea ice is discontinued, but can still be found in the previous releases. The data files are provided in both CSV and NetCDF format and contain, for each measurement, the following metadata: latitude, longitude, elevation, timestamp, method, reference of the data source and, when applicable, the name of the measurement group it belongs to (core name for SMB, profile name for density, station name for temperature). Data users are encouraged to cite all the original data sources that are being used. Issues about this release as well as suggestions of datasets to be added in next releases can be done on a dedicated user forum: https://github.com/SUMup-database/SUMup-data-suggestion/issues. Example scripts to use the SUMup 2023 files are made available on our script repository: https://github.com/SUMup-database/SUMup-example-scripts.

Description: Palaeoenvironmental records from permafrost sequences complemented by infrared stimulated luminescence (IRSL) and 230Th/U dates from Bol'shoy Lyakhovsky Island (73°20′N, 141°30′E) document the environmental history in the region for at least the past 200 ka. Pollen spectra and insect fauna indicate that relatively wet grasssedge tundra habitats dominated during an interstadial c. 200-170 ka BP. Summers were rather warm and wet, while stable isotopes reflect severe winter conditions. The pollen spectra reflect sparser grass-sedge vegetation during a Taz (Late Saalian) stage, c. 170-130 ka BP, with environmental conditions much more severe compared with the previous interstadial. Open Poaceae and Artemisia plant associations dominated vegetation at the beginning of the Kazantsevo (Eemian) c. 130 ka BP. Some shrubs (Alnus fruticosa, Salix, Betula nana) grew in more protected and wetter places as well. The climate was relatively warm during this time, resulting in the melting of Saalian ice wedges. Later, during the interglacial optimum, shrub tundra with Alnus fruticosa and Betula nana s.l. dominated vegetation. Climate was relatively wet and warm. Quantitative pollen-based climate reconstruction suggests that mean July temperatures were 4-5°C higher than the present during the optimum of the Eemian, while late Eemian records indicate significant climate deterioration. © 2004 Taylor & Francis.

Description: 〈jats:p〉Diatoms captivate both biologists and engineers with their remarkable mechanical properties and lightweight design principles inherent in their shells. Recent studies have indicated that diatom frustules possess optimized shapes that align with vibrational modes, suggesting an inherent adaptation to vibratory loads. The mode shape adaptation method is known to significantly alter eigenfrequencies of 1D and 2D structures to prevent undesired vibration amplitudes. Leveraging this insight, the diatom-inspired approach to deform structures according to mode shapes was extended to different complex 3D structures, demonstrating a significant enhancement in eigenfrequencies with distinct mode shapes. Through extensive parameter studies, frequency increases exceeding 200% were obtained, showcasing the method’s effectiveness. In the second study part, the studied method was integrated into a user-friendly, low-code software facilitating swift and automated structural adjustments for eigenfrequency optimization. The created software tools, encompassing various components, were successfully tested on the example structures demonstrating the versatility and practicality of implementing biomimetic strategies in engineering designs. Thus, the present investigation does not only highlight the noteworthiness of the structural adaptation method inspired by diatoms in maximizing eigenfrequencies, but also originate software tools permitting different users to easily apply the method to distinct structures that have to be optimized, e.g., lightweight structures in the mobility or aerospace industry that are susceptible toward vibrations.〈/jats:p〉

Description: A trend towards earlier sea-ice melt is detected in many ice-covered regions in the Arctic. The timing of the melt onset has a strong impact on the sea-ice energy budget. Melt onset changes the radiative properties of the ice due to increasing snow wetness and meltwater. So far, satellite passive microwave data are used to detect the melt onset. We analyzed transmitted radiation spectra as collected underneath drifting sea-ice using a remotely operated vehicle during the ARTofMELT expedition in the Fram Strait in spring 2023. We colocated those spectra with measurements of snow depth, sea ice and surface topography, chlorophyll-a concentration in the water column, and with aerial images. This combined dataset enables us to track down possible subsurface pathways and accumulation pools of meltwater. Areas of low snow load and depressed surface topography are characterized by higher transmitted radiation compared to areas with a thick snow cover. Those areas overlapped with areas that showed the first signs of surface melt. Chlorophyll-a concentrations varied only slightly in magnitude and did not match with the heterogeneous pattern of snow depth and ice topography. Here we discuss how to disentangle the influences of chlorophyll a and the subsurface meltwater on the spectral shape of transmitted radiation. We propose that upon successful disentanglement, the spectra can be used as an indicator for subsurface melting. Our study suggests that sea-ice melting starts subsurface and that measurements of transmitted solar radiation spectra could be used to identify the melt onset prior to surface melting. This can provide an interesting complementary information on melt occurrence and on the location of the water in the snowpack in addition to satellite passive microwave data.

Description: A trend towards earlier sea-ice melt is detected in many ice-covered regions in the Arctic. The timing of the melt onset has a strong impact on the sea-ice energy budget. Melt onset changes the radiative properties of the ice due to increasing snow wetness and meltwater. So far, satellite passive microwave data are used to detect the melt onset. We analyzed transmitted radiation spectra as collected underneath drifting sea-ice using a remotely operated vehicle during the ARTofMELT expedition in the Fram Strait in spring 2023. We colocated those spectra with measurements of snow depth, sea ice and surface topography, chlorophyll-a concentration in the water column, and with aerial images. This combined dataset enables us to track down possible subsurface pathways and accumulation pools of meltwater. Areas of low snow load and depressed surface topography are characterized by higher transmitted radiation compared to areas with a thick snow cover. Those areas overlapped with areas that showed the first signs of surface melt. Chlorophyll-a concentrations varied only slightly in magnitude and did not match with the heterogeneous pattern of snow depth and ice topography. Here we discuss how to disentangle the influences of chlorophyll a and the subsurface meltwater on the spectral shape of transmitted radiation. We propose that upon successful disentanglement, the spectra can be used as an indicator for subsurface melting. Our study suggests that sea-ice melting starts subsurface and that measurements of transmitted solar radiation spectra could be used to identify the melt onset prior to surface melting. This can provide an interesting complementary information on melt occurrence and on the location of the water in the snowpack in addition to satellite passive microwave data.

Description: The paralytic shellfish toxin (PST) profiles of Gymnodinium catenatum Graham have been reported for several strains from the Pacific coast of Mexico cultured under different laboratory conditions, as well as from natural populations. Up to 15 saxitoxin analogues occurred and the quantity of each toxin depended on the growth phase and culture conditions. Previous analysis of toxin profiles of G. catenatum isolated from Mexico have been based on post-column oxidation liquid chromatography with fluorescence detection (LC-FLD), a method prone to artefacts and non-specificity, leading to misinterpretation of toxin composition. We describe, for the first time, the complete toxin profile for several G. catenatum strains from diverse locations of the Pacific coast of Mexico. The new results confirmed previous reports on the dominance of the less potent sulfocarbamoyl toxins (C1/2); significant differences, however, in the composition (e.g., absence of saxitoxin, gonyautoxin 2/3 and neosaxitoxin) were revealed in our confirmatory analysis. The LC-MS/MS analyses also indicated at least seven putative benzoyl toxin analogues and provided support for their existence. This new toxin profile shows a high similarity (〉 80%) to the profiles reported from several regions around the world, suggesting low genetic variability among global populations.

Description: Coastal upwelling, driven by alongshore winds and characterized by cold sea surface temperatures and high upper-ocean nutrient content, is an important physical process sustaining some of the oceans’ most productive ecosystems. To fully understand the ocean properties in eastern boundary upwelling systems, it is important to consider the depth of the source waters being upwelled, as it affects both the SST and the transport of nutrients toward the surface. Here, we construct an upwelling source depth distribution for parcels at the surface in the upwelling zone. We do so using passive tracers forced at the domain boundary for every model depth level to quantify their contributions to the upwelled waters. We test the dependence of this distribution on the strength of the wind stress and stratification using high-resolution regional ocean simulations of an idealized coastal upwelling system. We also present an efficient method for estimating the mean upwelling source depth. Furthermore, we show that the standard deviation of the upwelling source depth distribution increases with increasing wind stress and decreases with increasing stratification. These results can be applied to better understand and predict how coastal upwelling sites and their surface properties have and will change in past and future climates.

Description: The genus Amphidinium Clap. & J. Lachm. comprises a high diversity of planktonic and benthic (epiphytic and sand-dwelling) dinoflagellates from marine and freshwater ecosystems. High morphological plasticity and vaguely defined genus characteristics (e.g., a small epicone size) have complicated the clear delineation of species boundaries. Although six Amphidinium morphospecies have been reported from Mexican coastal waters, species identifications are uncertain and not generally supported by molecular phylogenetic data. In this study, seven isolates of Amphidinium from diverse benthic coastal locations on the NE Pacific, Gulf of California, and southern Gulf of Mexico were subjected to critical morphological analysis using photonic and scanning electron microscopy. The phylogenetic reconstruction was based on nuclear-encoded, partial large-subunit (LSU) rDNA and internal transcribed spacer I and II (ITS1 and ITS2) sequences. The revised phylogenetic analysis was consistent with the traditional subdivision of the genus Amphidinium into two sister groups: Herdmanii and Operculatum clades. This study provided the first confirmed records of A. theodorei and A. massartii from coastal waters of Mexico. The molecular phylogenetic evidence indicated that the morphologically described A. cf. carterae from Baja California was in fact more closely allied with A. eilatiensis sequences. A few Amphidinium species are known to form toxigenic (i.e., fish-killing) harmful algal blooms worldwide, and therefore knowledge on species diversity and biogeography is critical in developing effective strategies for evaluating the potential emerging threat in Mexican coastal waters.

Description: Mexican studies on marine benthic dinoflagellates (MBD) began in 1942 from the offshore region of Oaxaca, based on water column samples. Subsequently, in ten Mexican maritime states, both epibenthos and plankton samples have been collected, species have been cultured, and field and laboratory studies have been carried out. Goals: The objective of this contribution is to review the studies on MBD in Mexican waters for current status and future risk assessment. Methods: Available literature on MBD from Mexico published from 1942 to 2022 was analyzed. Results: A review of the studies on MBD is presented herein, subdivided into four sections: (1) taxonomic diversity (morphological and molecular), (2) benthic phycotoxin vectors and toxigenicity, (3) toxicity and (4) species interactions. A map of the location of field populations of MBD and a reference list of taxonomic and ecological studies on MBD in Mexico is provided. A taxonomic list of ca. 60 species, mainly of Prorocentrum, followed in number by Amphidinium, Gambierdiscus, Ostreopsis, Coolia, and Sinophysis is presented. This list is accompanied by scanning electron microscopic images of 15 species. Knowledge of the toxigenicity of MBD is scarce, hence a reference table of known toxigenic species in Mexico and their respective associated syndromes is included. Conclusions: Studies on MBD in Mexico have slowly increased, probably due to the availability of a greater number of cultured strains, as well as to more extensive international collaborations. Confirmed links between benthic harmful algal bloom species and events associated with the etiology of toxic syndromes are rarely known in Mexico.

Description: Harmful algal blooms (HABs) have significant impacts on food safety and security through contamination or mass mortalities of aquatic organisms. Indeed, if not properly controlled, aquatic products contaminated with HAB biotoxins are responsible for potentially deadly foodborne diseases and when rapidly growing, HAB consequences include reduced dissolved oxygen in the ocean, dead zones, and mass mortalities of aquatic organisms. Improving HAB forecasting is an opportunity to develop early warning systems for HAB events such as food contamination, mass mortalities, or foodborne diseases. Surveillance systems have been developed to monitor HABs in many countries; however, the lead-time or the type of data (i.e. identification at the Species-level, determination of toxicity) may not be sufficient to take effective action for food safety management measures or other reasons, such as transfer of aquaculture products to other areas. Having early warning systems could help mitigate the impact of HABs and reduce the occurrence of HAB events. In this regard, FAO took the lead in the development of a Joint FAO-IOC-IAEA Technical Guidance for the Implementation of Early Warning Systems for HABs. The document will guide competent authorities and relevant institutions involved in consumer protection or environmental monitoring to implement early warning systems for HABs present in their areas (marine and brackish waters), specifically for those affecting food safety or food security (benthic HABs, fish-killing HABs, pelagic toxic HABs, and cyanobacteria HABs).

Description: As society's reliance on software systems escalates over time, so too does the cost of failure of these systems. Meanwhile, the complexity of software systems, as well as of their designs, is also ever-increasing, influenced by the proliferation of new tools and technologies to address intended societal needs. The traditional response to this complexity in software engineering and software architecture has been to apply rationalistic approaches to software design through methods and tools for capturing design rationale and evaluating various design options against a set of criteria. However, research from other fields demonstrates that intuition may also hold benefits for making complex design decisions. All humans, including software designers, use intuition and rationality in varying combinations. The aim of this article is to provide a comprehensive overview of what is known and unknown from existing research regarding the use and performance consequences of using intuition and rationality in software design decision-making. To this end, a systematic literature review has been conducted, with an initial sample of 3909 unique publications and a final sample of 26 primary studies. We present an overview of existing research, based on the literature concerning intuition and rationality use in software design decision-making and propose a research agenda with 14 questions that should encourage researchers to fill identified research gaps. This research agenda emphasizes what should be investigated to be able to develop support for the application of the two cognitive processes in software design decision-making.

Description: Die Grundstoffindustrie ist ein wichtiger Pfeiler des Wohlstands in Deutschland, sie garantiert Wertschöpfung und sorgt für über 550.000 hochwertige Arbeitsplätze. Um diese für die deutsche Wirtschaft wichtigen Branchen zu erhalten, müssen jetzt die Schlüsseltechnologien für eine CO2-arme Grundstoffproduktion entwickelt und für den großtechnischen Einsatz skaliert werden. Die vorliegende Analyse ist als Ergänzung zu der Studie "Klimaneutrale Industrie: Schlüsseltechnologien und Politikoptionen für Stahl, Chemie und Zement" gedacht. Die 13 in der erwähnten Studie vorgestellten Schlüsseltechnologien werden hier für die technisch interessierten Leserinnen und Leser eingehender beschrieben und diskutiert. Diese Publikation dient als Aufschlag für eine Diskussion über Technologieoptionen und Strategien für eine klimaneutrale Industrie. Alle Daten und Annahmen in dieser Analyse wurden mit Unternehmen und Branchenverbänden intensiv besprochen. Die quantitativen Aussagen sind trotzdem als vorläufig zu betrachten, da sich viele Technologien noch in einer frühen Entwicklungsphase befinden und Abschätzungen über Kosten mit großen Unsicherheiten verbunden sind.

Description: Die Grundstoffindustrie ist ein Pfeiler des Wohlstands in Deutschland, sie garantiert Wertschöpfung und sorgt für über 550.000 hochwertige Arbeitsplätze. Im Ausland steht Made in Germany für höchste Qualität und Innovationsdynamik. Aber: Trotz Effizienz­steigerungen sind die Emissionen der Industrie in den letzten Jahren nicht gefallen und durch die nationalen und internationalen Klimaschutzziele steigt der Druck. Die zentrale Frage lautet daher: Wie kann die Grundstoffindustrie in Deutschland bis spätestens 2050 klimaneutral werden - und gleichzeitig ihre starke Stellung im internationalen Wettbewerbs­umfeld behalten? Agora Energiewende und das Wuppertal Institut haben im Rahmen dieses Projekts in zahlreichen Workshops mit Industrie, Verbänden, Gewerkschaften, Ministerien und der Zivilgesellschaft die Zukunft für eine klimaneutrale Industrie diskutiert und einen Lösungsraum aus technologischen Optionen und politischen Rahmenbedingungen skizziert. In den Workshops wurde deutlich: Die Industrie steht in den Startlöchern, die Herausforderung Klimaschutz offensiv anzugehen. Die fehlenden Rahmenbedingungen und der bisher unzureichende Gestaltungswille der Politik, innovative Instrumente umzusetzen, hindern sie jedoch voranzugehen. Es ist höchste Zeit, dass sich das ändert. Denn jede neue Industrieanlage muss klimasicher sein - schließlich hat sie eine Laufzeit bis weit über das Jahr 2050 hinaus. Diese Publikation soll einen Beitrag dazu leisten, richtungssicher investieren zu können.

Description: A complete mitochondrial genome of Great Knot (Calidris tenuirostris), MK992912, was published by He and colleagues in 2020. Here we show that this mitogenome is actually a chimera containing DNA fragments of both C. tenuirostris (15,567 bp, 92.8%) and Pacific Golden Plover (Pluvialis fulva, 1208 bp, 7.2%). Detecting such errors is possible before publication if each sequenced fragment is separately analyzed phylogenetically before assembling the fragments into a single mitogenome. This mitogenome has been re-used in at least four phylogenies. The error is documented to avoid the perpetuation of erroneous sequence information in the literature.

Description: Background: The genus Clavicornaltica Scherer 1974 consists of very small, soil-dwelling flea beetles in South, Southeast and East Asia. Due to their diminutive size and morphological similarities, very little is known about their ecology and taxonomical diversity. It is likely that further studies will reveal this genus to be much more speciose than the 30 species currently recognised. New information: A new species of Clavicornaltica from Brunei Darussalam is described, C. mataikanensis Otani et al., sp. nov. This is the second species of this genus recorded from Ulu Temburong National Park.

Description: 1. The interruption of plant-pollinator interactions may threaten global plant diversity, food security and ecosystem stability. Recent reports of strong declines in both insects and plants point to insect decline as a driver of plant decline. However, it is still unknown whether these trends are related as plants often produce seeds without the need for insect pollinators, and to what extent insect-pollinated plants have declined in relation to plants not pollinated by insects. 2. In this study, we hypothesise that natural plant communities have shifted away from insect-pollination. We combined 365,768 vegetation plots from 1930 to 2017 in the Netherlands and plant traits to assess the changes in occurrences of plants pollinated by different modes. Furthermore, we included key drivers in plant decline—specifically nitrogen, moisture and habitat types—as interaction factors to explore the persistence of the observed changes under different environmental conditions. 3. The proportion of insect-pollinated plants has declined while that of wind-pollinated plants has increased over the last 87 years. This proportional change reflects an absolute decrease in the number of insect-pollinated species and an increase in the number of wind-pollinated species. 4. Synthesis and applications. This study implies that Dutch landscapes are losing insect-pollinated plant species, which is likely due, at least in part, to the decline in pollination services. Our results of quantifying the decline in insect-pollinated plants support the necessity and urgency of taking conservation initiatives. Several management strategies and policy recommendations could be applied to alleviate the decline of insect-pollinated plants and ensure crop safety. For example, conserving natural environments by reducing nitrogen deposition may support local plants and insect pollinators. Additionally, there is a particular need for focused efforts to protect natural grasslands, as these areas harbour many insect-pollinated plants, which have experienced declines. Finally, monitoring and assessing the state of both pollinators and (insect-pollinated) plants is needed to assess the progress of conservation measures. While recognising the interdependence of pollinators and pollinated plants, it is crucial to extend efforts beyond pollinator conservation alone to effectively safeguard insect- pollinated plants and ensure crop safety.

Description: The genus Calonectria includes many important plant pathogens with a wide global distribution. In order to better understand the reproductive biology of these fungi, we characterised the structure of the mating type locus and flanking genes using the genome sequences for seven Calonectria species. Primers to amplify the mating type genes in other species were also developed. PCR amplification of the mating type genes and multi-gene phylogenetic analyses were used to investigate the mating strategies and evolution of mating type in a collection of 70 Calonectria species residing in 10 Calonectria species complexes. Results showed that the organisation of the MAT locus and flanking genes is conserved. In heterothallic species, a novel MAT gene, MAT1-2-12 was identified in the MAT1-2 idiomorph; the MAT1-1 idiomorph, in most cases, contained the MAT1-1-3 gene. Neither MAT1-1-3 nor MAT1-2-12 was found in homothallic Calonectria (Ca.) hongkongensis, Ca. lateralis, Ca. pseudoturangicola and Ca. turangicola. Four different homothallic MAT locus gene arrangements were observed. Ancestral state reconstruction analysis provided evidence that the homothallic state was basal in Calonectria and this evolved from a heterothallic ancestor.

Description: New records of notoaturine water mites (Aturidae: Notoaturinae) from New Zealand are presented. Five new species are described: Evidaturus longiscutatus n. sp., Kritaturus (Kritaturus) longipalpis n. sp., Planaturus simpsonensis n. sp., Tryssaturus longwood n. sp. and Zelandalbia thibaulti n. sp. The males are described for the first time for Planaturus pileatus Smit, 2017 and Zelandalbia cf. hopkinsi Imamura, 1978 and the females are described for the first time for Kritaturus (Kritaturus) sornus Cook, 1983, Paratryssaturus zodelus Cook, 1983 and Taintaturus accidens Cook, 1983.

Description: The red turpentine beetle (RTB; Dendroctonus valens) is a bark beetle that is native to Central and North America. This insect is well-known to live in association with a large number of Ophiostomatalean fungi. The beetle is considered a minor pest in its native range, but has killed millions of indigenous pine trees in China after its appearance in that country in the late 1990s. In order to increase the base of knowledge regarding the RTB and its symbionts, surveys of the beetle’s fungal associates were initially undertaken in China, and in a subsequent study in its native range in NorthAmerica.Atotal of 30 Ophiostomatalean species that included several undescribed taxa, were identified in these surveys. In the present study, seven of the undescribed taxa collected during the surveys were further characterised based on their morphological characteristics and multi-gene phylogenies. We proceeded to describe five of these as novel Leptographium spp. and two as new species of Ophiostoma. Four of the Leptographium spp. resided in the G. galeiformis-species complex, while one formed part of the L. olivaceumspecies complex. One Ophiostoma sp. was a member of the O. ips-species complex, while the only new species from China was closely related to O. floccosum. Two of the previously undescribed taxa from North America were shown to be congeneric with L. terebrantis, implying that this species was most often isolated in association with the RTB in North America. The undescribed taxon from North America was identified as O. ips, and like L. terebrantis, this species was also not recognized during the initial North American survey. Resolving the identities of these taxa provides essential baseline information to better understand the movement of fungal pathogens with this beetle. This then enhances our ability to accurately assess and predict the risks of invasions by these and related fungi.

Description: The ongoing biodiversity crisis, driven by factors such as land-use change and global warming, emphasizes the need for effective ecological monitoring methods. Acoustic monitoring of biodiversity has emerged as an important monitoring tool. Detecting human voices in soundscape monitoring projects is useful both for analyzing human disturbance and for privacy filtering. Despite significant strides in deep learning in recent years, the deployment of large neural networks on compact devices poses challenges due to memory and latency constraints. Our approach focuses on leveraging knowledge distillation techniques to design efficient, lightweight student models for speech detection in bioacoustics. In particular, we employed the MobileNetV3-Small-Pi model to create compact yet effective student architectures to compare against the larger EcoVADteacher model, a well-regarded voice detection architecture in eco-acoustic monitoring. The comparative analysis included examining various configurations of the MobileNetV3-Small-Pi-derived student models to identify optimal performance. Additionally, a thorough evaluation of different distillation techniques was conducted to ascertain the most effective method for model selection. Our findings revealed that the distilled models exhibited comparable performance to the EcoVAD teacher model, indicating a promising approach to overcoming computational barriers for real-time ecological monitoring.

Description: Strains with a yeast-like appearance were frequently collected in two surveys on the biodiversity of fungi in Germany, either associated with necroses in wood of Prunus trees in orchards in Saxony, Lower Saxony and Baden-Württemberg or captured in spore traps mounted on grapevine shoots in a vineyard in Rhineland-Palatinate. The morphology of the strains was reminiscent of the genus Collophorina: all strains produced aseptate conidia on integrated conidiogenous cells directly on hyphae, on discrete phialides, adelophialides and by microcyclic conidiation, while in some strains additionally endoconidia or conidia in conidiomata were observed. Blastn searches with the ITS region placed the strains in the Leotiomycetes close to Collophorina spp. Analyses based on morphological and multi-locus sequence data (LSU, ITS, EF-1α, GAPDH) revealed that the 152 isolates from wood of Prunus spp. belong to five species including C. paarla, C. africana and three new species. A further ten isolates from spore traps belonged to seven new species, of which one was isolated from Prunus wood as well. However, a comparison with both LSU and ITS sequence data of these collophorina-like species with reference sequences from further Leotiomycetes revealed the genus Collophorina to be polyphyletic and the strains to pertain to several genera within the Phacidiales. Collophorina paarla and C. euphorbiae are transferred to the newly erected genera Pallidophorina and Ramoconidiophora, respectively. The new genera Capturomyces, Variabilispora and Vexillomyces are erected to accommodate five new species isolated from spore traps. In total nine species were recognised as new to science and described as Collophorina badensis, C. germanica, C. neorubra, Capturomyces funiculosus, Ca. luteus, Tympanis inflata, Variabilispora flava, Vexillomyces palatinus and V. verruculosus.

Description: Species of Diaporthe (syn. Phomopsis) are important endophytes, saprobes and pathogens, infecting a wide range of plants and resulting in important crop diseases. However, the species occurring on pear remain largely unresolved. In this study, a total of 453 Diaporthe isolates were obtained from branches of Pyrus plants (including P. bretschneideri, P. communis, P. pyrifolia and P. ussuriensis collected from 12 provinces in China) showing shoot canker symptoms. Phylogenetic analyses based on five loci (ITS, TEF, CAL, HIS, and TUB) coupled with morphology of 113 representative isolates revealed that 19 Diaporthe species were isolated, representing 13 known species (including D. caryae, D. cercidis, D. citrichinensis, D. eres, D. fusicola, D. ganjae, D. hongkongensis, D. padina, D. pescicola, D. sojae, D. taoicola, D. unshiuensis and D. velutina) and six new species described here as D. acuta, D. chongqingensis, D. fulvicolor, D. parvae, D. spinosa and D. zaobaisu. Although Koch’s postulates confirmed all species to be pathogenic, a high degree of variation in aggressiveness was observed. Moreover, these species have a high diversity, plasticity, and prevalence related to the geographical location and pear species involved.

Description: Gymnosporangium species (Pucciniaceae, Pucciniales, Basidiomycota) are the causal agents of cedarapple rust diseases, which can lead to significant economic losses to apple cultivars. Currently, the genus contains 17 described species that alternate between spermogonial/aecial stages on Malus species and telial stages on Juniperus or Chamaecyparis species, although these have yet to receive a modern systematic treatment. Furthermore, prior studies have shown that Gymnosporangium does not belong to the Pucciniaceae sensu stricto (s.str.), nor is it allied to any currently defined rust family. In this study we examine the phylogenetic placement of the genus Gymnosporangium. We also delineate interspecific boundaries of the Gymnosporangium species on Malus based on phylogenies inferred from concatenated data of rDNA SSU, ITS and LSU and the holomorphic morphology of the entire life cycle. Based on these results, we propose a new family, Gymnosporangiaceae, to accommodate the genus Gymnosporangium, and recognize 22 Gymnosporangium species parasitic on Malus species, of which G. lachrymiforme, G. shennongjiaense, G. spinulosum, G. tiankengense and G. kanas are new. Typification of G. asiaticum, G. fenzelianum, G. juniperi-virginianae, G. libocedri, G. nelsonii, G. nidus-avis and G. yamadae are proposed to stabilize the use of names. Morphological and molecular data from type materials of 14 Gymnosporangium species are provided. Finally, morphological characteristics, host alternation and geographical distribution data are provided for each Gymnosporangium species on Malus.

Description: Trunk disease fungal pathogens reduce olive production globally by causing cankers, dieback, and other decline-related symptoms on olive trees. Very few fungi have been reported in association with olive dieback and decline in South Africa. Many of the fungal species reported from symptomatic olive trees in other countries have broad host ranges and are known to occur on other woody host plants in the Western Cape province, the main olive production region of South Africa. This survey investigated the diversity of fungi and symptoms associated with olive dieback and decline in South Africa. Isolations were made from internal wood symptoms of 145 European and 42 wild olive trees sampled in 10 and 9 districts, respectively. A total of 99 taxa were identified among 440 fungal isolates using combinations of morphological and molecular techniques. A new species of Pseudophaeomoniella, P. globosa, had the highest incidence, being recovered from 42.8 % of European and 54.8 % of wild olive samples. This species was recovered from 9 of the 10 districts where European olive trees were sampled and from all districts where wild olive trees were sampled. Members of the Phaeomoniellales (mainly P. globosa) were the most prevalent fungi in five of the seven symptom types considered, the only exceptions being twig dieback, where members of the Botryosphaeriaceae were more common, and soft/white rot where only Basidiomycota were recovered. Several of the species identified are known as pathogens of olives or other woody crops either in South Africa or elsewhere in the world, including species of Neofusicoccum, Phaeoacremonium, and Pleurostoma richardsiae. However, 81 of the 99 taxa identified have not previously been recorded on olive trees and have unknown interactions with this host. These taxa include one new genus and several putative new species, of which four are formally described as Celerioriella umnquma sp. nov., Pseudophaeomoniella globosa sp. nov., Vredendaliella oleae gen. & sp. nov., and Xenocylindrosporium margaritarum sp. nov.

Description: Specimens of Nectria spp. and Nectriella rufofusca were obtained from the fungarium of Pier Andrea Saccardo, and investigated via a morphological and molecular approach based on MiSeq technology. ITS1 and ITS2 sequences were successfully obtained from 24 specimens identified as ‘Nectria’ sensu Saccardo (including 20 types) and from the type specimen of Nectriella rufofusca. For Nectria ambigua, N. radians and N. tjibodensis only the ITS1 sequence was recovered. On the basis of morphological and molecular analyses new nomenclatural combinations for Nectria albofimbriata, N. ambigua, N. ambigua var. pallens, N. granuligera, N. peziza subsp. reyesiana, N. radians, N. squamuligera, N. tjibodensis and new synonymies for N. congesta, N. flageoletiana, N. phyllostachydis, N. sordescens and N. tjibodensis var. crebrior are proposed. Furthermore, the current classification is confirmed for Nectria coronata, N. cyanostoma, N. dolichospora, N. illudens, N. leucotricha, N. mantuana, N. raripila and Nectriella rufofusca. This is the first time that these more than 100-yr-old specimens are subjected to molecular analysis, thereby providing important new DNA sequence data authentic for these names.

Description: Members of the genus Cytospora are often reported as endophytes, saprobes or phytopathogens, primarily causing canker diseases of woody host plants. They occur on a wide range of hosts and have a worldwide distribution. Although several species have in the past been reported from China, the vast majority are not known from culture or DNA phylogeny. The primary aim of the present study was thus to clarify the taxonomy and phylogeny of a large collection of Cytospora species associated with diverse hosts in China. Cytospora spp. were collected in northeast, northwest, north and southwest China, indicating that the cold and dry environments favour these fungi. In this paper, we provide an assessment of 52 Cytospora spp. in China, focussing on 40 species represented by 88 isolates from 28 host genera. Based on a combination of morphology and a six-locus phylogeny (ITS, LSU, act1, rpb2, tef1-α and tub2), 13 new species and one new combination are introduced. The majority of the species investigated here appear to be host-specific, although further collections and pathogenicity studies will be required to confirm this conclusion.

Description: Bees are important actors in terrestrial ecosystems and are recognised for their prominent role as pollinators. In the Iberian Peninsula, approximately 1,100 bee species are known, with nearly 100 of these species being endemic to the Peninsula. A reference collection of DNA barcodes, based on morphologically identified bee specimens, representing 514 Iberian species, was constructed. The "InBIO Barcoding Initiative Database: DNA Barcodes of Iberian bees" dataset contains records of 1,059 sequenced specimens. The species of this dataset correspond to about 47% of Iberian bee species diversity and 21% of endemic species diversity. For peninsular Portugal only, the corresponding coverage is 71% and 50%. Specimens were collected between 2014 and 2022 and are deposited in the research collection of Thomas Wood (Naturalis Biodiversity Center, The Netherlands), in the FLOWer Lab collection at the University of Coimbra (Portugal), in the Andreia Penado collection at the Natural History and Science Museum of the University of Porto (MHNC-UP) (Portugal) and in the InBIO Barcoding Initiative (IBI) reference collection (Vairão, Portugal).

Description: Plantation-grown Eucalyptus (Myrtaceae) and other trees residing in the Myrtales have been widely planted in southern China. These fungal pathogens include species of Cryphonectriaceae that are well-known to cause stem and branch canker disease on Myrtales trees. During recent disease surveys in southern China, sporocarps with typical characteristics of Cryphonectriaceae were observed on the surfaces of cankers on the stems and branches of Myrtales trees. In this study, a total of 164 Cryphonectriaceae isolates were identified based on comparisons of DNA sequences of the partial conserved nuclear large subunit (LSU) ribosomal DNA, internal transcribed spacer (ITS) regions including the 5.8S gene of the ribosomal DNA operon, two regions of the β-tubulin (tub2/tub1) gene, and the translation elongation factor 1-alpha (tef1) gene region, as well as their morphological characteristics. The results showed that eight species reside in four genera of Cryphonectriaceae occurring on the genera Eucalyptus, Melastoma (Melastomataceae), Psidium (Myrtaceae), Syzygium (Myrtaceae), and Terminalia (Combretaceae) in Myrtales. These fungal species include Chrysoporthe deuterocubensis, Celoporthe syzygii, Cel. eucalypti, Cel. guangdongensis, Cel. cerciana, a new genus and two new species, as well as one new species of Aurifilum. These new taxa are hereby described as Parvosmorbus gen. nov., Par. eucalypti sp. nov., Par. guangdongensis sp. nov., and Aurifilum terminali sp. nov. Pathogenicity tests showed that the eight species of Cryphonectriaceae are pathogenic to two Eucalyptus hybrid seedlings, Melastoma sanguineum branches, and Psidium guajava and Syzygium jambos seedlings. The overall data showed that Chr. deuterocubensis is the most aggressive, followed by Par. eucalypti. Significant differences in tolerance were observed between the two tested Eucalyptus hybrid genotypes, suggesting that disease-tolerant genotypes can be selected for disease management in the Eucalyptus industry.

Description: Reef cores are a powerful tool for investigating temporal changes in reef communities. Radiometric dating facilitates the determination of vertical accretion rates, which has allowed for examination of local-regional controlling factors, such as subsidence and sea level changes. Coral reefs must grow at sufcient rates to keep up with sea level rise, or risk ‘drowning.’ As sea level is expected to rise signifcantly in the next 100 years and beyond, it is important to understand whether reefs will be able to survive. Historical records of reef accretion rates extracted from cores provide valuable insights into extrinsic controlling factors of reef growth and are instrumental in helping predict if future reefs can accrete at rates needed to overcome predicted sea level changes. While extensive research exists at local and regional scales, limited attention has been given to identifying global patterns and drivers. To address this, we present “RADReef”: A global dataset of dated Holocene reef cores. RADReef serves as a foundation for further research on past, present and future reef accretion.

Description: The possibility that the Amazon forest system could soon reach a tipping point, inducing large-scale collapse, has raised global concern. For 65 million years, Amazonian forests remained relatively resilient to climatic variability. Now, the region is increasingly exposed to unprecedented stress from warming temperatures, extreme droughts, deforestation and fires, even in central and remote parts of the system. Long existing feedbacks between the forest and environmental conditions are being replaced by novel feedbacks that modify ecosystem resilience, increasing the risk of critical transition. Here we analyse existing evidence for five major drivers of water stress on Amazonian forests, as well as potential critical thresholds of those drivers that, if crossed, could trigger local, regional or even biome-wide forest collapse. By combining spatial information on various disturbances, we estimate that by 2050, 10% to 47% of Amazonian forests will be exposed to compounding disturbances that may trigger unexpected ecosystem transitions and potentially exacerbate regional climate change. Using examples of disturbed forests across the Amazon, we identify the three most plausible ecosystem trajectories, involving diferent feedbacks and environmental conditions. We discuss how the inherent complexity of the Amazon adds uncertainty about future dynamics, but also reveals opportunities for action. Keeping the Amazon forest resilient in the Anthropocene will depend on a combination of local eforts to end deforestation and degradation and to expand restoration, with global eforts to stop greenhouse gas emissions.

Description: Novel species of fungi described in this study include those from various countries as follows: Australia, Austroboletus asper on soil, Cylindromonium alloxyli on leaves of Alloxylon pinnatum, Davidhawksworthia quintiniae on leaves of Quintinia sieberi, Exophiala prostantherae on leaves of Prostanthera sp., Lactifluus lactiglaucus on soil, Linteromyces quintiniae (incl. Linteromyces gen. nov.) on leaves of Quintinia sieberi, Lophotrichus medusoides from stem tissue of Citrus garrawayi, Mycena pulchra on soil, Neocalonectria tristaniopsidis (incl. Neocalonectria gen. nov.) and Xyladictyochaeta tristaniopsidis on leaves of Tristaniopsis collina, Parasarocladium tasmanniae on leaves of Tasmannia insipida, Phytophthora aquae-cooljarloo from pond water, Serendipita whamiae as endophyte from roots of Eriochilus cucullatus, Veloboletus limbatus (incl. Veloboletus gen. nov.) on soil. Austria, Cortinarius glaucoelotus on soil. Bulgaria, Suhomyces rilaensis from the gut of Bolitophagus interruptus found on a Polyporus sp. Canada, Cantharellus betularum among leaf litter of Betula, Penicillium saanichii from house dust. Chile, Circinella lampensis on soil, Exophiala embothrii from rhizosphere of Embothrium coccineum. China, Colletotrichum cycadis on leaves of Cycas revoluta. Croatia, Phialocephala melitaea on fallen branch of Pinus halepensis. Czech Republic, Geoglossum jirinae on soil, Pyrenochaetopsis rajhradensis from dead wood of Buxus sempervirens. Dominican Republic, Amanita domingensis on litter of deciduous wood, Melanoleuca dominicana on forest litter. France, Crinipellis nigrolamellata (Martinique) on leaves of Pisonia fragrans, Talaromyces pulveris from bore dust of Xestobium rufovillosum infesting floorboards. French Guiana, Hypoxylon hepaticolor on dead corticated branch. Great Britain, Inocybe ionolepis on soil. India, Cortinarius indopurpurascens among leaf litter of Quercus leucotrichophora. Iran, Pseudopyricularia javanii on infected leaves of Cyperus sp., Xenomonodictys iranica (incl. Xenomonodictys gen. nov.) on wood of Fagus orientalis. Italy, Penicillium vallebormidaense from compost. Namibia, Alternaria mirabibensis on plant litter, Curvularia moringae and Moringomyces phantasmae (incl. Moringomyces gen. nov.) on leaves and flowers of Moringa ovalifolia, Gobabebomyces vachelliae (incl. Gobabebomyces gen. nov.) on leaves of Vachellia erioloba, Preussia procaviae on dung of Procavia capensis. Pakistan, Russula shawarensis from soil on forest floor. Russia, Cyberlindnera dauci from Daucus carota. South Africa, Acremonium behniae on leaves of Behnia reticulata, Dothiora aloidendri and Hantamomyces aloidendri (incl. Hantamomyces gen. nov.) on leaves of Aloidendron dichotomum, Endoconidioma euphorbiae on leaves of Euphorbia mauritanica, Eucasphaeria proteae on leaves of Protea neriifolia, Exophiala mali from inner fruit tissue of Malus sp., Graminopassalora geissorhizae on leaves of Geissorhiza splendidissima, Neocamarosporium leipoldtiae on leaves of Leipoldtia schultzii, Neocladosporium osteospermi on leaf spots of Osteospermum moniliferum, Neometulocladosporiella seifertii on leaves of Combretum caffrum, Paramyrothecium pituitipietianum on stems of Grielum humifusum, Phytopythium paucipapillatum from roots of Vitis sp., Stemphylium carpobroti and Verrucocladosporium carpobroti on leaves of Carpobrotus quadrifolius, Suttonomyces cephalophylli on leaves of Cephalophyllum pilansii. Sweden, Coprinopsis rubra on cow dung, Elaphomyces nemoreus from deciduous woodlands. Spain, Polyscytalum pini-canariensis on needles of Pinus canariensis, Pseudosubramaniomyces septatus from stream sediment, Tuber lusitanicum on soil under Quercus suber. Thailand, Tolypocladium flavonigrum on Elaphomyces sp. USA, Chaetothyrina spondiadis on fruits of Spondias mombin, Gymnascella minnisii from bat guano, Juncomyces patwiniorum on culms of Juncus effusus, Moelleriella puertoricoensis on scale insect, Neodothiora populina (incl. Neodothiora gen. nov.) on stem cankers of Populus tremuloides, Pseudogymnoascus palmeri from cave sediment. Vietnam, Cyphellophora vietnamensis on leaf litter, Tylopilus subotsuensis on soil in montane evergreen broadleaf forest. Morphological and culture characteristics are supported by DNA barcodes.

Description: The origin, transport pathway, and spatial variability of total organic carbon (OC) in the western Himalayan glaciers are poorly understood compared to those of black carbon (BC) and dust, but it is critically important to evaluate the climatic role of OC in the region. By applying the distribution of OC activation energy; 14C activity; and radiogenic isotopes of 208Pb/204Pb, 207Pb/204Pb, and 206Pb/204Pb in glacial debris and atmospheric particulate matter (PM10 size fraction), we demonstrate that 98.3 ± 1.6 and 1.7 ± 1.6% of OC in western Himalayan glaciers are derived from biomass and petrogenic sources, respectively. The δ13C and N/C composition indicates that the biomass is a complex mixture of C3 vegetation and autochthonous photoautotrophic input modified by heterotrophic microbial activity. The data set reveals that the studied western Himalayan glacier has negligible contributions from fossil-fuel-derived particles, which contrasts to the central and eastern Himalayan glaciers that have significant contributions from fossil fuel sources. We show that this spatial variability of OC sources relates to regional differences in air mass transport pathways and precipitation regimes over the Himalaya. Moreover, our observation suggests that biomass-derived carbon could be the only primary driver of carbon-induced glacier melting in the western Himalaya.

Description: Fluoride contamination in groundwater is a worldwide phenomenon. Excess fluoride in drinking water causes serious health risks, and as a result, fluoride contamination of water resources is a global concern. In this study, an attempt has been made to provide the distribution of fluoride and related non-carcinogenic health hazards to local individual groups (males, females, and children separately) in the fluoride endemic region of Patiala, Punjab located in the Northern Indo-Gangetic Plain (IGP). The study shows that the dissolved groundwater fluoride concentration ranged between 1.5 and 9.2 mg/L with ∼98% of the sampling locations having fluoride levels higher than the permissible limit. Samples collected from deeper aquifers (〉284 m bgl) showed ∼27% more fluoride contamination compared to those collected from 〈284 m bgl. Maximum incidence of elevated fluoride concentrations was observed in the eastern part of the study area in-sync with groundwater movement. The hazard quotient of fluoride (HQFluoride) calculated to assess the non-carcinogenic health risk was higher than the unitary value in all individual groups suggesting a prevalence of distressful fluorosis and chronic health risk. Results show that the children are the most vulnerable to fluoride toxicity followed by males and females. Our results are consistent with the recent trends in an increase in dental, skeletal fluorosis, and liver functional damage problems reported in children and adults of the studied region. The study area, therefore, needs the urgent attention of policymakers and government agencies to implement proper water management and cost-effective fluoride remedial measures to reduce the current and future chronic health risks associated with high fluoride intake.

Description: Groundwater is a vital resource for humans, non-human species, and ecosystems. It has allowed the development of human evolution and civilizations throughout history (e.g., Wittfogel 1956, Tempelhoff et al. 2009, Cuthbert and Ashley 2014, Roberts 2014). However, it faces multiple potential threats that make it vulnerable and fragile. Climate change and human activities are the primary causes that have led to water cycle disruptions, particularly a decline in groundwater quality and quantity (e.g., Gleeson et al. 2020, Chaminé et al. 2022, Richardson et al. 2023). Climate variability has induced droughts, floods, and other extreme weather conditions, significantly impacting groundwater in many regions. Meanwhile, human activities such as over-abstraction, ground contamination, deforestation, land-use change, and other anthropogenic pressures have further compromised groundwater status. Nonetheless, groundwater continues to fulfill water demands in many regions or during specific periods. Therefore, concerted efforts are imperative to ensure its sustainability. So, conservation practices and nature-based solutions must be adopted to efficiently manage groundwater and shield it from additional potential hazards or risks (e.g., contamination, pollution, or over-abstraction). Failure to act quickly can result in the loss of this critical resource, with severe consequences for the economy, society, and ecosystems. From this perspective, it is imperative to prioritize actions underscored by technical-scientific integrity, environmental responsibility, societal sensitivity, and ethical practices.

Description: Published

Description: 97

Description: OS: Terza missione

Description: OSA5: Energia e georisorse

Description: JCR Journal

Description: Around 9.7 million years ago there was an abrupt collapse in diversity; the so-called 'Vallesian Crisis'. This was seen as the transition point to a climate with more seasonality and open landscapes.Using a fossil dataset from Miocene Eurasia, the influence of dataset quality on the severity of this crisis, which animals were most affected and their distribution patterns was studied.The crisis’ victims have three things in common: they are mainly forest dwellers, they date back to the Middle Miocene (16-11.1 Ma), and they are rare during the early Vallesian. The high Vallesian biodiversity was caused by the arrival of new immigrants in addition to older transient groups, possibly due to the unique coastal conditions.Major differences existed between the coastal region and the interior of the Iberian Peninsula. Some species appeared in the Vallès-Penedès, but never reached the inland. The 'Vallesian Crisis', while seen understandably as a time of abrupt and severe extinction, was thus largely a local turnover event.

Description: Se caracterizó y evaluó el estado de conservación de los pastos marinos en áreas de interés conservacionista del Archipiélago Sabana-Camagüey en el periodo 2001-2003, considerando variables descriptivas de las angiospermas marinas, de la estructura del macrofitobentos y abióticas para conocer las causas de su afectación. Las áreas estudiadas fueron las bahías de Cárdenas, Santa Clara, Buena Vista, de Perros, Jigüey, La Gloria y Nuevitas, así como algunas lagunas arrecifales. Los pastos marinos mejor conservados se encontraron en las zonas con mayor intercambio con el océano, destacándose las lagunas arrecifales. El deterioro de los pastos marinos se debió principalmente al aumento de la turbidez por contaminación orgánica cerca de la isla principal en sectores costeros de las bahías de Cárdenas, Santa Clara y Buena Vista, y a este factor, junto con el incremento de la salinidad, en las bahías de Perros y Jigüey. Las condiciones más propicias para el desarrollo de los pastos parecen ser: la visibilidad submarina 〉 1 m, la salinidad 〈 43 ups, la variabilidad de salinidad 〈 10 ups, la DQO 〈 5,6 mgO2 L-1 y el nitrógeno total 〈 173 μM en el agua. La especie de angiosperma dominante fue Thalassia testudinum, seguida por Syringodium filiforme y Halodule wrightii, que dominaron donde disminuyó la luz y aumentaron los nutrientes. El inventario del macrofitobentos en el ASC acumuló 227 especies (100 Rhodophyta, 26 Ochrophyta, 96 Chlorophyta y cinco Magnoliophyta), con 66 nuevos registros para la zona y 16, para Cuba. Las macroalgas más frecuentes fueron de los órdenes Bryopsidales (Chlorophyta) y Ceramiales (Rhodophyta). La estructura del macrofitobentos estuvo modulada por los mismos factores que afectan el desarrollo de las angiospermas, con una riqueza específica menor donde está deteriorado el hábitat.

Description: PhD

Description: In the marine realm, microorganisms are responsible for the bulk of primary production, thereby sustaining marine life across all trophic levels. Longhurst provinces have distinct microbial fingerprints; however, little is known about how microbial diversity and primary productivity change at finer spatial scales. Here, we sampled the Atlantic Ocean from south to north (~50°S–50°N), every ~0.5° latitude. We conducted measurements of primary productivity, chlorophyll-a and relative abundance of 16S and 18S rRNA genes, alongside analyses of the physicochemical and hydrographic environment. We analysed the diversity of autotrophs, mixotrophs and heterotrophs, and noted distinct patterns among these guilds across provinces with high and low chlorophyll-a conditions. Eukaryotic autotrophs and prokaryotic heterotrophs showed a shared inter-province diversity pattern, distinct from the diversity pattern shared by mixotrophs, cyanobacteria and eukaryotic heterotrophs. Additionally, we calculated samplewise productivity-specific length scales, the potential horizontal displacement of microbial communities by surface currents to an intrinsic biological rate (here, specific primary productivity). This scale provides key context for our trophically disaggregated diversity analysis that we could relate to underlying oceanographic features. We integrate this element to provide more nuanced insights into the mosaic-like nature of microbial provincialism, linking diversity patterns to oceanographic transport through primary production.

Description: Contrasting models predict two different climate change scenarios for the Southern Ocean (SO), forecasting either less or stronger vertical mixing of the water column. To investigate the responses of SO phytoplankton to these future conditions, we sampled a natural diatom dominated (63%) community from today’s relatively moderately mixed Drake Passage waters with both low availabilities of iron (Fe) and light. The phytoplankton community was then incubated at these ambient open ocean conditions (low Fe and low light, moderate mixing treatment), representing a control treatment. In addition, the phytoplankton was grown under two future mixing scenarios based on current climate model predictions. Mixing was simulated by changes in light and Fe availabilities. The two future scenarios consisted of a low mixing scenario (low Fe and higher light) and a strong mixing scenario (high Fe and low light). In addition, communities of each mixing scenario were exposed to ambient and low pH, the latter simulating ocean acidification (OA). The effects of the scenarios on particulate organic carbon (POC) production, trace metal to carbon ratios, photophysiology and the relative numerical contribution of diatoms and nanoflagellates were assessed. During the first growth phase, at ambient pH both future mixing scenarios promoted the numerical abundance of diatoms (∼75%) relative to nanoflagellates. This positive effect, however, vanished in response to OA in the communities of both future mixing scenarios (∼65%), with different effects for their productivity. At the end of the experiment, diatoms remained numerically the most abundant phytoplankton group across all treatments (∼80%). In addition, POC production was increased in the two future mixing scenarios under OA. Overall, this study suggests a continued numerical dominance of diatoms as well as higher carbon fixation in response to both future mixing scenarios under OA, irrespective of different changes in light and Fe availability.

Description: Mesopelagic fish (meso-fish) are central species within the Southern Ocean (SO). However, their ecosystem role and adaptive capacity to climate change are rarely integrated into marine protected area (MPAs) assessments. This is a pity given their importance as crucial prey and predators in food webs, coupled with the impacts of climate change. Here, we estimate the habitat distribution of nine meso-fish using an ensemble model approach (MAXENT, random forest, and boosted regression tree). Four climate model simulations were used to project their distribution under two representative concentration pathways (RCP4.5 and RCP8.5) for short-term (2006–2055) and long-term (2050–2099) periods. In addition, we assess the ecological representativeness of established and proposed MPAs under climate change scenarios using meso-fish as indicator species. Our models show that all species shift poleward in the future. Lanternfishes (family Myctophidae) are predicted to migrate poleward more than other families (Paralepididae, Nototheniidae, Bathylagidae, and Gonostomatidae). In comparison, lanternfishes were projected to increase habitat area in the eastern SO but lose area in the western SO; the opposite was projected for species in other families. Important areas (IAs) of meso-fish are mainly distributed near the Antarctic Peninsula and East Antarctica. Proposed MPAs cover 23% of IAs at present and 38% of IAs in the future (RCP8.5, long-term future). Many IAs of meso-fish still need to be included in MPA proposals, such as the Prydz Bay and the seas around the Antarctic Peninsula. Our results provide a framework for designing new MPAs incorporating climate change adaptation strategies for MPA management.

Description: Sediment reworking by benthic infauna, namely bioturbation, is of pivotal importance in expansive soft-sediment environments such as the Wadden Sea. Bioturbating fauna facilitate ecosystem functions such as bentho-pelagic coupling and sediment nutrient remineralization capacities. Yet, these benthic fauna are expected to be profoundly affected by current observed rising sea temperatures. In order to predict future changes in ecosystem functioning in soft-sediment environments like the Wadden Sea, knowledge on the underlying processes such as sediment reworking, is crucial. Here, we tested how temperature affects bioturbation and its associated ecosystem processes, such as benthic nutrient fluxes and sediment oxygen consumption, using luminophore tracers and sediment incubation cores. We used a controlled mesocosm experiment set-up with key Wadden Sea benthos species: the burrowing polychaetes Arenicola marina and Hediste diversicolor, the bivalve Cerastoderma edule, and the tube-building polychaete Lanice conchilega. The highest bioturbation rates were observed from A. marina, reaching up to 375 cm2yr−1; followed by H. diversicolor, with 124 cm2yr−1 being the peak bioturbation rate for the ragworm. Additionally, the sediment reworking activity of A. marina facilitated nearly double the amount of silicate efflux compared to any other species. Arenicola marina and H. diversicolor accordingly facilitated stronger nutrient effluxes under a warmer temperature than L. conchilega and C. edule. The oxygen uptake of A. marina and H. diversicolor within the sediment incubation cores was correspondingly enhanced with a higher temperature. Thus, increases in sea temperatures may initially be beneficial to ecosystem functioning in the Wadden Sea as faunal bioturbation is definitely expedited, leading to a tighter coupling between the sediment and overlying water column. The enhanced bioturbation activity, oxygen consumption, and facilitated nutrient effluxes from these invertebrates themselves, will aid in the ongoing high levels of primary productivity and organic matter production.

Description: 〈jats:title〉Abstract〈/jats:title〉〈jats:sec〉〈jats:title〉Aim〈/jats:title〉〈jats:p〉Within the intensively‐studied, well‐documented latitudinal diversity gradient, the deep‐sea biodiversity of the present‐day Norwegian Sea stands out with its notably low diversity, constituting a steep latitudinal diversity gradient in the North Atlantic. The reason behind this has long been a topic of debate and speculation. Most prominently, it is explained by the deep‐sea glacial disturbance hypothesis, which states that harsh environmental glacial conditions negatively impacted Norwegian Sea diversities, which have not yet fully recovered. Our aim is to empirically test this hypothesis. Specific research questions are: (1) Has deep‐sea biodiversity been lower during glacials than during interglacials? 〈jats:italic〉(〈/jats:italic〉2) Was there any faunal shift at the Mid‐Brunhes Event (MBE) when the mode of glacial–interglacial climatic change was altered?〈/jats:p〉〈/jats:sec〉〈jats:sec〉〈jats:title〉Location〈/jats:title〉〈jats:p〉Norwegian Sea, deep sea (1819–2800 m), coring sites MD992277, PS1243, and M23352.〈/jats:p〉〈/jats:sec〉〈jats:sec〉〈jats:title〉Time period〈/jats:title〉〈jats:p〉620.7–1.4 ka (Middle Pleistocene–Late Holocene).〈/jats:p〉〈/jats:sec〉〈jats:sec〉〈jats:title〉Taxa studied〈/jats:title〉〈jats:p〉Ostracoda (Crustacea).〈/jats:p〉〈/jats:sec〉〈jats:sec〉〈jats:title〉Methods〈/jats:title〉〈jats:p〉We empirically test the deep‐sea glacial disturbance hypothesis by investigating whether diversity in glacial periods is consistently lower than diversity in interglacial periods. Additionally, we apply comparative analyses to determine a potential faunal shift at the MBE, a Pleistocene event describing a fundamental shift in global climate.〈/jats:p〉〈/jats:sec〉〈jats:sec〉〈jats:title〉Results〈/jats:title〉〈jats:p〉The deep Norwegian Sea diversity was not lower during glacial periods compared to interglacial periods. Holocene diversity was exceedingly lower than that of the last glacial period. Faunal composition changed substantially between pre‐ and post‐MBE.〈/jats:p〉〈/jats:sec〉〈jats:sec〉〈jats:title〉Main conclusions〈/jats:title〉〈jats:p〉These results reject the glacial disturbance hypothesis, since the low glacial diversity is the important precondition here. The present‐day‐style deep Norwegian Sea ecosystem was established by the MBE, more specifically by MBE‐induced changes in global climate, which has led to more dynamic post‐MBE conditions. In a broader context, this implies that the MBE has played an important role in the establishment of the modern polar deep‐sea ecosystem and biodiversity in general.〈/jats:p〉〈/jats:sec〉

Description: 〈jats:title〉Abstract〈/jats:title〉〈jats:p〉Extensive investigation of continental rift systems has been fundamental for advancing the understanding of extensional tectonics and modes of formation of new ocean basins. However, current rift classification schemes do not account for conjugate end members formed by Large Igneous Province crust, referring to thick mafic crust, sometimes including continental fragments. Here, we investigate the rifting of William's Ridge (Kerguelen Plateau) and Broken Ridge, components of the Kerguelen Large Igneous Province now situated in the Southeast Indian Ocean, and incorporate these end members into the deformation migration concept for rifted margins. We use multichannel seismic reflection profiles and data from scientific drill cores acquired on both conjugate margins to propose, for the first time, a combined tectono‐stratigraphic framework. We interpret seismic patterns, tectonic features, and magnetic anomaly picks to determine an across‐strike structural domain classification. This interpretation considers the rift system overall to be “magma‐poor” despite being located proximal to the Kerguelen plume but suggests that syn‐rift interaction between the Kerguelen mantle plume and the lithospheric structure of William's Ridge and Broken Ridge has controlled the along‐strike segmentation of both conjugates. We integrate seismic reflection and bathymetric data to test the hypothesis of predominantly transform motion, between the Australian and Antarctic plates, in Late Cretaceous and Paleogene time.〈/jats:p〉

Description: Ongoing climate warming in the western Canadian Arctic is leading to thawing of permafrost soils and subsequent mobilization of its organic matter pool. Part of this mobilized terrestrial organic matter enters the aquatic system as dissolved organic matter (DOM) and is laterally transported from land to sea. Mobilized organic matter is an important source of nutrients for ecosystems, as it is available for microbial breakdown, and thus a source of greenhouse gases. We are beginning to understand spatial controls on the release of DOM as well as the quantities and fate of this material in large Arctic rivers. Yet, these processes remain systematically understudied in small, high-Arctic watersheds, despite the fact that these watersheds experience the strongest warming rates in comparison. Here, we sampled soil (active layer and permafrost) and water (porewater and stream water) from a small ice wedge polygon (IWP) catchment along the Yukon coast, Canada, during the summer of 2018. We assessed the organic carbon (OC) quantity (using dissolved (DOC) and particulate OC (POC) concentrations and soil OC content), quality (δ13C DOC, optical properties and source apportionment) and bioavailability (incubations; optical indices such as slope ratio, Sr; and humification index, HIX) along with stream water properties (temperature, T; pH; electrical conductivity, EC; and water isotopes). We classify and compare different landscape units and their soil horizons that differ in microtopography and hydrological connectivity, giving rise to differences in drainage capacity. Our results show that porewater DOC concentrations and yield reflect drainage patterns and waterlogged conditions in the watershed. DOC yield (in mg DOC g−1 soil OC) generally increases with depth but shows a large variability near the transition zone (around the permafrost table). Active-layer porewater DOC generally is more labile than permafrost DOC, due to various reasons (heterogeneity, presence of a paleo-active-layer and sampling strategies). Despite these differences, the very long transport times of porewater DOC indicate that substantial processing occurs in soils prior to release into streams. Within the stream, DOC strongly dominates over POC, illustrated by ratios around 50, yet storm events decrease that ratio to around 5. Source apportionment of stream DOC suggests a contribution of around 50 % from permafrost/deep-active-layer OC, which contrasts with patterns observed in large Arctic rivers (12 ± 8 %; Wild et al., 2019). Our 10 d monitoring period demonstrated temporal DOC patterns on multiple scales (i.e., diurnal patterns, storm events and longer-term trends), underlining the need for high-resolution long-term monitoring. First estimates of Black Creek annual DOC (8.2 ± 6.4 t DOC yr−1) and POC (0.21 ± 0.20 t yr−1) export allowed us to make a rough upscaling towards the entire Yukon Coastal Plain (34.51 ± 2.7 kt DOC yr−1 and 8.93 ± 8.5 kt POC yr−1). Rising Arctic temperatures, increases in runoff, soil organic matter (OM) leaching, permafrost thawing and primary production are likely to increase the net lateral OC flux. Consequently, altered lateral fluxes may have strong impacts on Arctic aquatic ecosystems and Arctic carbon cycling.

Description: 〈jats:p〉This study presents the results of research on the climatic signal of radial growth of Siberian larch (〈jats:italic〉Larix cajanderi Mayr〈/jats:italic〉.) in the Omoloy River Basin, (north-eastYakutia). Tree-ring width chronologies were obtained from three sites  located in the valley complexes of subarctic tundra and forest-tundra ecotone, with chronologies spanning up to 498 years. Comparative analysis of radial growth dynamics and its statistical parameters indicated similar variability patterns within the study region. Dendroclimatic analysis revealed that the primary limiting factor determining the magnitude of radial growth in Siberianlarch is the air temperature during the first half of the growing season. Increasing temperatures have led to an increased role of precipitation and changes in the strength of growth-temperature correlations, especially in northern sites.This study highlights the potential for dendroclimatic and dendroecological researchin northern Yakutia.〈/jats:p〉

Description: Paleoceanographic reconstructions show that the strength of North Atlantic currents decreased during the Little Ice Age. In contrast, the role of ocean circulation in climate regulation during earlier historical epochs of the Common Era (C.E.) remains unclear. Here, we reconstruct sea surface temperature (SST) and salinity in the Caribbean Basin for the past 1700 years using the isotopic and elemental composition of planktic foraminifera tests. Centennial-scale SST and salinity variations in the Caribbean co-occur with (hydro)climate changes in the Northern Hemisphere and are linked to a North Atlantic SST forcing. Cold phases around 600, 800, and 1400 to 1600 C.E. are characterized by Caribbean salinification and Gulf of Mexico freshening that implies reductions in the strength of North Atlantic surface circulation. We suggest that the associated changes in the meridional salt advection contributed to the historical climate variability of the C.E.

Description: 〈jats:p〉Reconstructing interglacial marine environments helps us understand the climate change mechanisms of the past. To contribute to this body of knowledge, we studied a high-resolution 455 cm-thick sediment sequence of the Boreal (Eemian) marine beds directly overlying Moscovian (Saalian) moraine in the Bychye-2 section on the Pyoza River. We analyzed lithological and microfossil (foraminifers, ostracods, pollen, aquatic palynomorphs) variations at the studied site. Stratigraphical zonation is based on the local and well-established regional pollen zones, correlated with the western European pollen zones. The studied marine beds accumulated from the end of the Moscovian glacial (>131 ka) until ca. 119.5 ka. We distinguished three successive phases: a seasonally sea-ice-covered, relatively deep, freshened basin in the initial rapid flooding stage (>131–130.5 ka); a deep basin in the maximum flooding phase with less extensive sea ice cover (130.5–130.25 ka); and a shallow basin with reduced sea ice cover (130.25–119.5 ka). According to a pollen zone comparison with other sites, the regional glacioisostatic rebound started ca. 130 ka. The diverse warm-water assemblages of benthic foraminifers and ostracods containing typical Baltic Sea species occurred during the regression, mainly 128–124 ka, thus giving evidence for a relatively long-lasting connection between the White and Baltic Seas.〈/jats:p〉

Description: Multi-archive studies of climate events and archive-specific response times require synchronous time scales. Aligning common variations in the cosmogenic radionuclide production rate via curve fitting methods provides a tool for the continuous synchronization of natural environmental archives down to decadal precision. Based on this approach, we synchronize 10Be records from Western Gotland Basin (WGB, Baltic Sea) and Lake Kälksjön (KKJ, central Sweden) sediments to the 14C production time series from the IntCal20 calibration curve during the Mid-Holocene period ~6400 to 5200 a BP. Before the synchronization, we assess and reduce non-production variability in the 10Be records by using 10Be/9Be ratios and removing common variability with the TOC record from KKJ sediments based on regression analysis. The synchronizations to the IntCal20 14C production time scale suggest decadal to multi-decadal refinements of the WGB and KKJ chronologies. These refinements reduce the previously centennial chronological uncertainties of both archives to about ± 20 (WGB) and ±40 (KKJ) years. Combining proxy time series from the synchronized archives enables us to interpret a period of ventilation in the deep central Baltic Sea basins from ~6250 to 6000 a BP as possibly caused by inter-annual cooling reducing vertical water temperature gradients allowing deep water formation during exceptionally cold winters.

Description: Geomechanics has a marked impact on the safe and sustainable use of the subsurface. This Special Publication contains contributions detailing the latest efforts in present-day in-situ stress characterization, prediction and modelling from the borehole to plate-tectonic scale. A particular emphasis is on the uncertainties that are often associated with geomechanics.

Description: Supraglacial discharge of limiting micronutrients such as iron (Fe) into high-nutrient low-chlorophyll (HNLC) regions like the Southern Ocean has recently drawn global attention. In this study, we aim to understand the contribution of cryoconite holes (comprising a meltwater column with an underlying layer of sediment) to the discharge of Fe through the glacier runoff. Cryoconite hole meltwater collected from the Larsemann Hills, East Antarctica showed a higher concentration of dissolved Fe (dFe: 71.2 μgL−1) and total Fe extractable from suspended sediments (exFe: 362.1 μgL−1) than in the adjacent streams (dFe: 30.5 μgL−1; exFe: 21.2 μgL−1) and melt pools (dFe: 42.3 μgL−1; exFe: 5.8 μgL−1). Predictive pathways (using PICRUSt2) show that cryoconite hole bacterial communities could acquire Fe and other trace elements using different mechanisms, such as the biosynthesis of siderophores, and transport proteins, therefore influencing the trace metal chemistry in these and other environments that drain cryoconite hole contents. Estimated discharge of dFe (11.4 kg km−2 a−1) and exFe (57.9 kg km−2 a−1) within cryoconite holes are 2 and 17 times higher, respectively than the discharge from the adjacent supraglacial streams, indicating that cryoconite holes are an important source of potentially bioavailable Fe to the HNLC region.

Description: Die DIN 19700:2004-07 "Stauanlagen fordert für Hochwasserrückhaltebecken und Talsperren die Prüfung der Einwirkung von Erdbeben. Ausgehend von der Erdbebengefahr am Standort müssen Nachweise hinsichtlich der Zuverlässigkeit der Stauanlage im Erdbebenfall geführt werden. Für die Betreiber und die Wasserbehörden gibt das vorliegende Kompendium einen zusammenfassenden Überblick über die Grundlagen der Erdbebennachweisführung entsprechend den DIN-Vorgaben. Die Anforderungen an die Nachweisführung sowie eine Leistungsbeschreibung für die zu beauftragenden Fachbüros werden gegeben. Ferner werden Hinweise zum Betrieb der Stauanlage erläutert. Es wird dargestellt, wie die Stauanlagen in Hinsicht auf eine Erdbebeneinwirkung zu überwachen sind.

Description: Desert environments constitute one of the largest and yet most fragile ecosystems on Earth. Under the absence of regular precipitation, microorganisms are the main ecological component mediating nutrient fluxes by using soil components, like minerals and salts, and atmospheric gases as a source for energy and water. While most of the previous studies on microbial ecology of desert environments have focused on surface environments, little is known about microbial life in deeper sediment layers. Our study is extending the limited knowledge about microbial communities within the deeper subsurface of the hyperarid core of the Atacama Desert. By employing intracellular DNA extraction and subsequent 16S rRNA sequencing of samples collected from a soil pit in the Yungay region of the Atacama Desert, we unveiled a potentially viable microbial subsurface community residing at depths down to 4.20 m. In the upper 80 cm of the playa sediments, microbial communities were dominated by Firmicutes taxa showing a depth-related decrease in biomass correlating with increasing amounts of soluble salts. High salt concentrations are possibly causing microbial colonization to cease in the lower part of the playa sediments between 80 and 200 cm depth. In the underlying alluvial fan deposits, microbial communities reemerge, possibly due to gypsum providing an alternative water source. The discovery of this deeper subsurface community is reshaping our understanding of desert soils, emphasizing the need to consider subsurface environments in future explorations of arid ecosystems.

Description: The current crustal stress field is of key importance to understand geodynamic processes and to assess stability aspects during subsurface usage. To provide a 3-D continuous description of the stress state, linear elastic forward geomechanical-numerical models are used. These models solve the equilibrium of forces between gravitational volume forces and surfaces forces im- posed mainly by plate tectonics. The latter are responsible for the horizontal stress anisotropy and impose the inverse problem to estimate horizontal displacement boundary conditions that provide a fit best to horizontal stress magnitude data within the model volume. Ho wever , horizontal stress magnitude data have high uncertainties and they are sparse, clustered and not necessaril y representati ve for a larger rock v olume. Even w hen Bay esian statistics are incor - porated and additional stress information such as borehole failure observations or formation integrity test are used to further constrain the solution space, this approach may result in a low accuracy of the model results, that is the result is not correct. Here, we present an alternative approach that removes the dependence of the solution space based on stress magnitude data to avoid potential low accuracy . Initially , a solution space that contains all stress states that are physically reasonable is defined. Stress magnitude data and the additional stress information are then used in a Bayesian framework to e v aluate which solutions are more likely than others. We first show and validate our approach with a generic truth model and then apply it to a case study of the Molasse foreland basin of the Alps in Southern Germany. The results show that the model’s ability to predict a reliable stress state is increasing while the number of likely solutions may also increase, and that outlier of stress magnitude data can be identified. This alternative approach results in a substantial increase in computational speed as we perform most of the calculations anal yticall y.

Description: Preface of a special issue.

Description: Published

Description: 3365-3366

Description: OSA3: Climatologia e meteorologia spaziale

Description: JCR Journal

Description: Nowadays, unmanned aerial vehicles (UAVs), as well as unmanned surface vehicles (USVs) or unmanned underwater vehicles (UUVs), later on simply called drones, have reached a sufficient degree of maturity to allow their use for various purposes. Drones are used in remote sensing, in particular in geological mapping and architectural surveying. New applications continually appear; among them, disaster management, precision agriculture, weather forecast, wildlife monitoring, search and rescue, law enforcement, shipping and delivery, and also entertainment, with different type of sensors.

Description: Published

Description: 175

Description: OST5 Verso un nuovo Monitoraggio

Description: JCR Journal

Description: Since the last century, global warming has been triggering sea level rise at an unprecedented rate. In the worst case climate scenario, sea level could rise by up to 1.1 m above the current level, causing coastal inundation and cascading effects, thus affecting about one billion people around the world. Though widespread and threatening, the phenomenon is not well known to citizens as it is often overshadowed by other effects of global warming. Here, we show the results of an online survey carried out in 2020–2021 to understand the level of citizens’ knowledge on sea level rise including causes, effects, exacerbation in response to land subsidence and best practice towards mitigation and adaptation. The most important result of the survey is that citizens believe that it is up to governments to take action to cope with the effects of rising sea levels or mitigate the rise itself. This occurs despite the survey showing that they actually know what individuals can do and that a failure to act poses a threat to society. Gaps and preconceptions need to be eradicated by strengthening the collaboration between scientists and schools to improve knowledge, empowering our society.

Description: Published

Description: 367–379

Description: OSA4: Ambiente marino, fascia costiera ed Oceanografia operativa

Description: JCR Journal

Description: Editorial on the Research Topic Management and monitoring of natural disasters using remote sensing and ground-based data

Description: Published

Description: 1323627

Description: OST5 Verso un nuovo Monitoraggio

Description: JCR Journal

Description: A new analytical formula for H0, one of the three parameters (H0, g, and r) on which the NeQuick model is based to describe the altitude profile of the electron density above the F2-layer peak height hmF2, has recently been proposed. This new analytical representation of H0, called H0,corr, relies on numerical grids based on two different types of datasets. On one side, electron density observations by the Swarm satellites over Europe from December 2013 to September 2018, and on the other side, IRI UP (International Reference Ionosphere UPdate) maps over Europe of the critical frequency of the ordinary mode of propagation associated with the F2 layer, foF2, and hmF2, at 15 min cadence for the same period. The new NeQuick topside representation based on H0,corr, hereafter referred to as NeQuick-corr, improved the original NeQuick topside representation. This work updates the numerical grids of H0,corr by extending the underlying Swarm and IRI UP datasets until December 2021, thus allowing coverage of low solar activity levels, as well. Moreover, concerning Swarm, besides the original dataset, the calibrated one is considered, and corresponding grids of H0,corr calculated. At the same time, the role of g is investigated, by considering values different from the reference one, equal to 0.125, currently adopted. To understand what are the best H0,corr grids to be considered for the NeQuick-corr topside representation, vertical total electron content data for low, middle, and high latitudes, recorded from five low-Earth-orbit satellite missions (COSMIC/FORMOSAT-3, GRACE, METOP, TerraSAR-X, and Swarm) have been analyzed. The updated H0,corr grids based on the original Swarm dataset with a value for g = 0.15, and the updated H0,corr grids based on the calibrated Swarm dataset with a value for g = 0.14, are those for which the best results are obtained. The results show that the performance of the different NeQuick-corr models is reliable also for low latitudes, even though these are outside the spatial domain for which the H0,corr grids were obtained, and are dependent on solar activity.

Description: Published

Description: 498

Description: OSA3: Climatologia e meteorologia spaziale

Description: JCR Journal

Description: The integrated use of non-destructive geomatic and geophysical techniques such as close-range digital photogrammetry, laser scanner techniques, thermography, sonic and ultrasonic methods, resistivity, etc... for the diagnostics of the stone building materials of architectural structures has become increasingly dependent on the integration of different disciplines of applied research. As is well known many historic monuments are characterized by severe damage due to temporal degradation, problems caused by differential settlements of the foundations and various types of natural hazards. Therefore it is of great interest to test and develop effective, integrated non invasive procedures to detect the conservation state of the building materials of historic structures, and identify and prevent their potential vulnerability in order to preserve their intrinsic characteristics for a long time. For extensive applications, as well as for investigations on monuments or large architectural elements, scanning and digital high resolution images are particularly useful, thanks to their limited cost, high production and relatively simple reproducibility of the tests. These techniques give useful information on the shallow conditions of the investigated materials. Geophysical techniques such as the ultrasonic and resistivity methods are non-invasive and are considered the most appropriate to evaluate the internal structure and assess the quality of the stone materials of the architectural heritage. This paper presents an integrated approach that combines advanced geomatic survey procedures, such as close-range photogrammetry (CRP) based on high resolution images and Terrestrial Laser Scanner (TLS) techniques with a few geophysical techniques such as the ultrasonic and resistivity ones in order to test the effectiveness of the integrated approach in providing an effective diagnosis of stone building materials in the Basilica di San Saturnino (Cagliari – Italy). This Basilica is the oldest monument of the town of Cagliari (Italy) and represents an interesting synthesis of different construction techniques with heterogeneous stone materials of different origins. CRP and TLS were applied to the investigated elements with the aim of obtaining a natural colour texturized 2D-3D model with a calibrated scale and coordinates. The geometrical anomaly and reflectivity maps derived from the data of the CRP-TLS survey show the presence of some anomalies worthy of attention, but they were referred to the shallow materials. A further investigation on site using the ultrasonic pulse velocity (UPV) and electrical resistivity techniques were performed to investigate the materials in depth. The results of the CRP and TLS techniques allowed the best design of the ultrasonic and electrical techniques and also proved to be useful in the data interpretation phase.

Description: Published

Description: Vienna - Austria

Description: OSA5: Energia e georisorse

Description: Nel mese di maggio 2022 è iniziato uno sciame sismico, di breve durata, che ha interessato una piccola area del Chianti fiorentino a circa 15 km a sud dalla città di Firenze. I due terremoti più energetici hanno avuto una magnitudo momento pari a 3.7; nonostante la magnitudo modesta, tali eventi sono stati avvertiti distintamente fino a distanze di diverse decine di chilometri, e hanno destato preoccupazione nella popolazione prossima all’area epicentrale. Inoltre, dato l’ingente patrimonio artistico presente nel capoluogo toscano, questo episodio ha sollevato interrogativi sulla sua vulnerabilità anche a scuotimenti del suolo di piccola entità. Al fine di migliorare le conoscenze sulla ubicazione e le dimensioni delle strutture sismogenetiche attive in prossimità di Firenze, l’Istituto Nazionale di Geofisica e Vulcanologia (INGV) è intervenuto nell’area interessata dallo sciame attraverso il Gruppo Operativo (GO) di emergenza SISMIKO. Il 4 maggio, giorno successivo all’inizio dello sciame, cinque stazioni sismiche mobili sono state installate a distanza ravvicinata dall’area epicentrale, e integrate nel sistema di monitoraggio permanente INGV. Questo lavoro descrive le procedure relative a: (i) l’installazione, la manutenzione e la disinstallazione della rete sismica mobile; (ii) la gestione e il controllo di qualità dei dati acquisiti. Infine, vengono presentate, in riferimento al contesto sismotettonico dell’area, le caratteristiche spaziali e l’evoluzione temporale dello sciame, che ha presentato una piccola ripresa nell’attività sismica ad agosto del 2022, con un terremoto di magnitudo locale 2.7 e successive repliche.

Description: Published

Description: 1-26

Description: OST5 Verso un nuovo Monitoraggio

Description: JCR Journal

Description: The National Institute of Geophysics and Volcanology (INGV, Istituto Nazionale di Geofisica e Vulcanologia), is an italian public research institute established in 1999. Since its inception, the mission of INGV included seismic surveillance and earthquake monitoring in Italy. INGV is part of the Civil Defence system (Margheriti et al., 2021). INGV has offices in different parts of Italy and operates the Italian National Seismic Network (Rete Sismica Nazionale—RSN; INGV Seismological Data Centre, 2006) and other networks at national scale (Michelini et al., 2017). INGV also operates a temporary seismic network infrastructure, a pool of instruments used to densify seismic networks for scientific experiments or in response to damaging earthquakes and to increase monitoring capabilities during seismic sequences. SISMIKO is the operational task force of INGV whose core purpose is to rapidly deploy temporary seismic stations in response to moderate—large magnitude earthquakes or in areas where a seismic sequence is causing concerns and/or scientific interest (Moretti et al., 2016). By reducing the spatial distance between the seismic stations, temporary deployments can improve the RSN detection capability and the accuracy of the earthquake locations. SISMIKO was established in 2015 by Lucia Margheriti and Milena Moretti, so they became responsible for INGV emergency deployments of the temporary networks. SISMIKO involves INGV technicians and researchers from all over Italy, from Milano to Catania (see acknowledgments), grouped together by common interest technical and scientific issues. SISMIKO coordinates all INGV groups working on seismic emergencies (Figure 1). The data acquired by the SISMIKO temporary networks, are made available to the scientific community, without any restrictions, via italian node of the European Integrated Data Archive portal (EIDA1; Danecek et al., 2021). Datasets are archived in near real-time in the “Standard for the Exchange of Earthquake Data (SEED)” format and have an associated Digital Object Identifier (DOI). The data are used for monitoring, surveillance and for scientific research. Since its establishment, SISMIKO has installed seven temporary seismic networks, including the one used to monitor the 2016–2018 seismic sequence in central Italy (Moretti et al., 2016). The most recent activations of SISMIKO were in May and November 2022: Chianti-Fiorentino (Piccinini et al., 2022; 2023) and North Marche coast (D’Alema et al., 2022b), respectively. The following section briefly describes the history of the INGV emergency mobile network.

Description: Published

Description: 1146579

Description: OST5 Verso un nuovo Monitoraggio

Description: JCR Journal

Description: In this paper, we outline the scientific objectives, the experimental layout, and the collaborations envisaged for the GINGER (Gyroscopes IN GEneral Relativity) project. The GINGER project brings together different scientific disciplines aiming at building an array of Ring Laser Gyroscopes (RLGs), exploiting the Sagnac effect, to measure continuously, with sensitivity better than picorad/s, large bandwidth (ca. 1 kHz), and high dynamic range, the absolute angular rotation rate of the Earth. In the paper, we address the feasibility of the apparatus with respect to the ambitious specifications above, as well as prove how such an apparatus, which will be able to detect strong Earthquakes, very weak geodetic signals, as well as general relativity effects like Lense-Thirring and de Sitter, will help scientific advancements in Theoretical Physics, Geophysics, and Geodesy, among other scientific fields.

Description: Published

Description: 203–234

Description: OST1 Alla ricerca dei Motori Geodinamici

Description: JCR Journal

Description: The latest version of the CPTI15 seismic catalogue (January 2022) includes more than two hundred earthquakes marked AMGNDT95. Their parameters are derived from expeditious studies produced as part of the GNDT/CNR ‘Hazard Project’ (1993-1995). Some of them simply parameterise data taken from bibliographic references in the PFG85 catalogue, i.e., mostly Mario Baratta’s seismological compilation “I terremoti d’Italia” [1901] or twentieth-century seismological bulletins. Others go back as far as the original sources of the references themselves. As part of the B2 Convention between INGV and DPC (2016-2021), a review of these earthquakes was initiated, starting with the most relevant ones, for which a good margin of improvement in knowledge can be assumed. At the same time, first-level research was also begun on a dozen or so earthquakes of low energy, but still above the damage threshold, which for various reasons had never been studied so far and whose parameters in the CPTI15 are still those of the POS85 catalogue. We present here the results of the study of about thirty earthquakes belonging to both categories. The overall result is generally a strong improvement of the available information, from which it will be possible to derive epicentral parameters more up-to-date and more robust than the previous ones.

Description: Questo lavoro è stato realizzato nell’ambito della Convenzione fra INGV e Dipartimento nazionale della Protezione Civile, Allegato B2.

Description: Published

Description: 1-260

Description: 4T. Sismicità dell'Italia

Description: JCR Journal

Description: Upscaling plant biomass distribution and dynamics is essential for estimating carbon stocks and carbon balance. In this respect, the Russian Far East is among the least investigated sub-Arctic regions despite its known vegetation sensitivity to ongoing warming. We representatively harvested above-ground biomass (AGB; separated by dominant taxa) at 40 sampling plots in central Chukotka. We used ordination to relate field-based taxa projective cover and Landsat-derived vegetation indices. A general additive model was used to link the ordination scores to AGB. We then mapped AGB for paired Landsat-derived time slices (i.e. 2000/2001/2002 and 2016/2017), in four study regions covering a wide vegetation gradient from closed-canopy larch forests to barren alpine tundra. We provide AGB estimates and changes in AGB that were previously lacking for central Chukotka at a high spatial resolution and a detailed description of taxonomical contributions. Generally, AGB in the study region ranges from 0 to 16 kg m−2, with Cajander larch providing the highest contribution. Comparison of changes in AGB within the investigated period shows that the greatest changes (up to 1.25 kg m−2 yr−1) occurred in the northern taiga and in areas where land cover changed to larch closed-canopy forest. As well as the notable changes, increases in AGB also occur within the land-cover classes. Our estimations indicate a general increase in total AGB throughout the investigated tundra–taiga and northern taiga, whereas the tundra showed no evidence of change in AGB.

Description: With two exceptions, no general patterns of patchiness of the megabenthos were found on the Antarctic shelf and off northeast Greenland. Underwater videos were used as a sampling method and Morisita's Index of Dispersion for statistical analysis. A gradient from randomness to patchiness occurred for most taxa, whereas the pattern of asteroids could not be distinguished from randomness. In the Antarctic, the totals of other mobile animals were less aggregated than for sessile taxa. The findings are interpreted as a result of ecological complexity within species assemblages.

Description: The aim of the expedition CACOON Sea was to investigate the transition from fresh water to salt water and its impact on fate and quality on dissolved and particulate organic and inorganic carbon and nitrogen. This is in accordance with the main Changing Arctic Carbon cycle in the cOastal Ocean Near-shore (CACOON, https://www.changing-arctic-ocean.ac.uk/project/cacoon/) project goal to investigate the changing freshwater export and impact of terrestrial permafrost thaw into the near-shore zone of the Laptev Sea.

Description: With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore cross- cutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge.The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system scientific research and provide an important foundation for advancing multiscale modeling capabilities in the Arctic.

Description: Future precipitation levels remain uncertain because climate models have struggled to reproduce observed variations in temperature-precipitation correlations. Our analyses of Holocene proxy-based temperature-precipitation correlations and hydrological sensitivities from 2,237 Northern Hemisphere extratropical pollen records reveal a significant latitudinal dependence and temporal variations among the early, middle, and late Holocene. These proxy-based variations are largely consistent with patterns obtained from transient climate simulations (TraCE21k). While high latitudes and subtropical monsoon areas show mainly stable positive correlations throughout the Holocene, the mid-latitude pattern is temporally and spatially more variable. In particular, we identified a reversal from positive to negative temperature-precipitation correlations in the eastern North American and European mid-latitudes from the early to mid-Holocene that mainly related to slowed down westerlies and a switch to moisture-limited convection under a warm climate. Our palaeoevidence of past temperature-precipitation correlation shifts identifies those regions where simulating past and future precipitation levels might be particularly challenging.

Description: With the CACOON project, we aim to quantify the effect of changing freshwater export and terrestrial permafrost thaw on the type and fate of river-borne organic matter (OM) delivered to Arctic coastal waters, and resultant changes on ecosystem functioning in the coastal Arctic Ocean. The CACOON ice expedition was the first step to set the observational basis for the projects combined observational, experimental and modelling approach. With the gained sample material, we will conduct laboratory experiments to parameterise the susceptibility of terrigenous carbon to abiotic and biotic transformation and losses, and then use the results from these to deliver a marine ecosystem model capable of representing the major biogeochemical cycles of carbon, nutrients and OM cycling in these regions. We will apply this model to assess how future changes to freshwater runoff and terrigenous carbon fluxes alter the biogeochemical structure and function of shelf ecosystems. Our aims for the project are the following: • generate novel seasonally-explicit datasets of OM source and transformation across the Lena River nearshore environments • identify and parameterise key abiotic and biotic processes affecting terrestrial organic matter fluxes from land-to-ocean • deliver projections of how future changes to freshwater runoff and terrestrial organic matter fluxes will alter the biogeochemical structure and function of shelf ecosystems.

Description: Lowland permafrost landscapes are experiencing dramatic changes as the climate in the Arctic has been warming almost four times the rate of the global average in the past four decades. On the Alaskan North Slope, extensive thermokarst processes are steering the dynamics of lakes and drained lake basins (DLBs). With progressing climate change, re-aggradation of permafrost in DLBs becomes potentially impeded. Additionally, along the Beaufort Sea coast, thaw-induced destabilization is causing substantial erosion, exposing previously frozen terrestrial deposits to the marine environment. The consequences for the biogeochemical system, which holds significant amounts of organic carbon, remain understudied. Therefore, we aim to investigate the carbon pool characteristics in thermokarst terrain close to Utqiaġvik. Sediment cores were sampled in 2022 and include two thermokarst lakes, one DLB and one undisturbed upland core. While West Twin Lake has freshwater conditions, East Twin Lake exhibits brackish water. The up to 2 m long sediment cores are investigated with a multidisciplinary approach. Bio- and hydrochemical analyses offer a detailed understanding of the current carbon pool properties. Additionally, n-alkane biomarker analyses, accompanied by carbon isotopy and the C/N ratio, serve as proxies to characterize the degradation state of organic carbon and its changes post permafrost thaw. Initial findings on carbon quantity and quality are presented, along with preliminary results from a 12-month-long incubation experiment. In this experiment, carbon dioxide and methane production rates are measured at ten depths along the sediment cores. The outcomes of this study contribute to a more comprehensive understanding of organic carbon degradation and its implications for the future carbon pool at a landform-specific level.

Description: Drilling of a 21.8-m-deep borehole on top of the 10.5-m-high Nori pingo that stands at 32 m asl in Grøndalen Valley (Spitsbergen) revealed a 16.1-m-thick massive ice enclosed by frozen sediments. The hydrochemical compositions of both the massive ice and the sediment extract show a prevalence of Na+ and Cl� ions throughout the core. The upper part of the massive ice (stage A) has low mineralization and shows an isotopically closed-system trend in δ18O and δD isotopes decreasing down-core. Stage B exhibits high mineralization and an isotopically semi-open system. The crystallographic structure of Nori pingo’s massive ice provides evidence of several large groundwater intrusions that support the defined formation stages. Analysis of local aquifers leads to suggest that the pingo was hydraulically sourced through a local fault zone by low mineralized sodium–bicarbonate groundwater of a Paleogene strata aquifer. This groundwater was enriched by sodium and chloride ions while filtering through marine valley sediments with residual salinity. The comparison between the sodium–chloride-dominated massive ice of the Nori pingo and the sodium–bicarbonate-dominated ice of the adjacent Fili pingo that stands higher up the valley may serve as an indicator for groundwater source patterns of other Nordenskiöld Land pingos.

Description: To explore the potential of urban settings as habitats for testate amoebae, five historical parks in Potsdam (Germany) were sampled at different sites. A total of 32 sampling sites was chosen in proximity to deciduous (Acer, Castanea, Fagus, Tilia, Platanus, Quercus) and coniferous (Fraxinus, Picea, Pinus, Tsuga) trees. Meadows and creeks were also sampled. The overall taxonomic record comprises 76 species and sub-species. High species numbers of 〉20 per sample were found in meadows and below Fagus, Tilia, and Quercus trees. The species richness per park ranges from 33 to 46 taxa. Most species belong to the eurybiontic ecological group, although litter-inhabiting and hygrophilic and hydrophilic species were also present. Common species found in more than 50% of all samples (superdominants) belong to the genera Centropyxis, Cyclopyxis, Euglypha, and Trinema. Interestingly, the rare Frenopyxis stierlitzi which inhabits tree hollows was found as a recently described species in a new genus Frenopyxis BOBROV & MAZEI 2020 in the Babelsberg Park. The studied testate amoebae are characterized by a high degree of morphological and morphometric plasticity. Therefore, the study of testate amoebae in urban settings will reveal new insights into their ecology and enhance the definition of morphometric variability for single species.

Description: Permafrost thaw in northern ecosystems may cause large quantities of carbon (C) to move from soil to atmospheric pools. Because soil microbial communities play a critical role in regulating C fluxes from soils, we examined microbial activity and greenhouse gas production soon after permafrost thaw and ground collapse (into collapse‐scar bogs), relative to the permafrost plateau or older thaw features. Using multiple field and laboratory‐based assays at a field site in interior Alaska, we show that the youngest collapse‐scar bog had the highest CH4 production potential from soil incubations, and, based upon temporal changes in porewater concentrations and 13C‐CH4 and 13C‐CO2, had greater summer in situ rates of respiration, methanogenesis, and surface CH4 oxidation. These patterns could be explained by greater C and N availability in the young bog, while alternative terminal electron accepting processes did not play a significant role. Field diffusive CH4 fluxes from the young bog were 4.1 times greater in the shoulder season and 1.7–7.2 times greater in winter relative to older bogs, but not during summer. Greater relative CH4 flux rates in the shoulder season and winter could be due to reduced CH4 oxidation relative to summer, magnifying the importance of differences in production. Both the permafrost plateau and collapse‐scar bogs were sources of C to the atmosphere due in large part to winter C fluxes. In collapse scar bogs, winter is a critical period when differences in thermokarst age translates to differences in surface fluxes.

Description: Background: Extreme terrestrial, analogue environments are widely used models to study the limits of life and to infer habitability of extraterrestrial settings. In contrast to Earth’s ecosystems, potential extraterrestrial biotopes are usually characterized by a lack of oxygen. Methods: In the MASE project (Mars Analogues for Space Exploration), we selected representative anoxic analogue environments (permafrost, salt-mine, acidic lake and river, sulfur springs) for the comprehensive analysis of their microbial communities. We assessed the microbiome profile of intact cells by propidium monoazide-based amplicon and shotgun metagenome sequencing, supplemented with an extensive cultivation effort. Results: The information retrieved from microbiome analyses on the intact microbial community thriving in the MASE sites, together with the isolation of 31 model microorganisms and successful binning of 15 high-quality genomes allowed us to observe principle pathways, which pinpoint specific microbial functions in the MASE sites compared to moderate environments. The microorganisms were characterized by an impressive machinery to withstand physical and chemical pressures. All levels of our analyses revealed the strong and omnipresent dependency of the microbial communities on complex organic matter. Moreover, we identified an extremotolerant cosmopolitan group of 34 poly-extremophiles thriving in all sites. Conclusions: Our results reveal the presence of a core microbiome and microbial taxonomic similarities between saline and acidic anoxic environments. Our work further emphasizes the importance of the environmental, terrestrial parameters for the functionality of a microbial community, but also reveals a high proportion of living microorganisms in extreme environments with a high adaptation potential within habitability borders.

Description: Northern latitudes have been significantly impacted by recent climate warming, which has increased the probability of experiencing extreme weather events. To comprehensively understand hydroclimate change and reconstruct hydroclimatic anomalies such as drought periods, appropriate proxy records reaching further back in time beyond meteorological measurements are needed. Here we present a 220-year (2015–1790 CE), continuous, stable oxygen isotope record of diatoms (δ18Odiatom) from Lake Khamra (59.99° N, 112.98° E) in eastern Siberia, an area highly sensitive to climate change and for which there is a demand for palaeohydrological data. This high-resolution proxy record was obtained from a 210Pb–137Cs-dated sediment short core and analysed to reconstruct hydroclimate variability at a sub-decadal scale. The interpretation of the δ18Odiatom record is supported by meteorological data, modern isotope hydrology and geochemical analyses of the same sediment, which is indicative of the conditions in the lake and catchment. A comparison with meteorological data going back to 1930 CE revealed that the δ18Odiatom record of Lake Khamra is primarily influenced by regional precipitation changes rather than the air temperature. We identified winter precipitation, which enters the lake as isotopically depleted snowmelt water, as the key process impacting the diatom isotope variability. We related the overall depletion of δ18Odiatom in recent decades to an observed increase in winter precipitation in the area, likely associated with the global air temperature rise, Arctic sea ice retreat and increased moisture transport inland. Available palaeoclimate proxy records, including a fire reconstruction for the same lake, support the idea that the new record is a valuable hydroclimate proxy that is indicative of precipitation deficits and excludes solar insolation and air temperature as primary driving forces, even before the first meteorological recordings. We propose two possible hydroclimatic anomalies that were detected in the Lake Khamra δ18Odiatom record: one at the beginning of the 19th century and a second prominent event in the 1950s. Both are interpreted as prolonged dry periods associated with enriched δ18Odiatom values likely caused by reduced winter precipitation, which coincide with phases of reconstructed severe wildfires in the region. Despite the apparent pristine lake area, we observed a three- to fourfold increase in mercury concentrations and accumulation rates within the sediment record since the early 20th century, which is partly attributed to human air pollution.

Description: Boreal forests cover over half of the global permafrost area and protect underlying permafrost. Boreal forest development, therefore, has an impact on permafrost evolution, especially under a warming climate. Forest disturbances and changing climate conditions cause vegetation shifts and potentially destabilize the carbon stored within the vegetation and permafrost. Disturbed permafrost-forest ecosystems can develop into a dry or swampy bush- or grasslands, shift toward broadleaf- or evergreen needleleaf-dominated forests, or recover to the pre-disturbance state. An increase in the number and intensity of fires, as well as intensified logging activities, could lead to a partial or complete ecosystem and permafrost degradation. We study the impact of forest disturbances (logging, surface, and canopy fires) on the thermal and hydrological permafrost conditions and ecosystem resilience. We use a dynamic multilayer canopy-permafrost model to simulate different scenarios at a study site in eastern Siberia. We implement expected mortality, defoliation, and ground surface changes and analyze the interplay between forest recovery and permafrost. We find that forest loss induces soil drying of up to 44%, leading to lower active layer thicknesses and abrupt or steady decline of a larch forest, depending on disturbance intensity. Only after surface fires, the most common disturbances, inducing low mortality rates, forests can recover and overpass pre-disturbance leaf area index values. We find that the trajectory of larch forests after surface fires is dependent on the precipitation conditions in the years after the disturbance. Dryer years can drastically change the direction of the larch forest development within the studied period.

Description: Warming air and sea temperatures, longer open-water seasons and sea-level rise promote the erosion of permafrost coasts in the Arctic, which profoundly impacts organic matter pathways. Although estimates on organic carbon (OC) fluxes from erosion exist for some parts of the Arctic, little is known about how much OC is transformed into greenhouse gases (GHGs). In this study we investigated two different coastal erosion scenarios on Qikiqtaruk – Herschel Island (Canada) and estimate the potential for GHG formation. We distinguished between a delayed release represented by mud debris draining a coastal thermoerosional feature and a direct release represented by cliff debris at a low collapsing bluff. Carbon dioxide (CO2) production was measured during incubations at 4 °C under aerobic conditions for two months and were modelled for four months and a full year. Our incubation results show that mud debris and cliff debris lost a considerable amount of OC as CO2 (2.5 ± 0.2 and 1.6 ± 0.3% of OC, respectively). Although relative OC losses were highest in mineral mud debris, higher initial OC content and fresh organic matter in cliff debris resulted in a ~three times higher cumulative CO2 release (4.0 ± 0.9 compared to 1.4 ± 0.1 mg CO2 gdw-1), which was further increased by the addition of seawater. After four months, modelled OC losses were 4.9 ± 0.1 and 3.2 ± 0.3% in set-ups without seawater and 14.3 ± 0.1 and 7.3 ± 0.8% in set-ups with seawater. The results indicate that a delayed release may support substantial cycling of OC at relatively low CO2 production rates during long transit times onshore during the Arctic warm season. By contrast, direct erosion may result in a single CO2 pulse and less substantial OC cycling onshore as transfer times are short. Once eroded sediments are deposited in the nearshore, highest OC losses can be expected. We conclude that the release of CO2 from eroding permafrost coasts varies considerably between erosion types and residence time onshore. We emphasize the importance of a more comprehensive understanding of OC degradation during the coastal erosion process to improve thawed carbon trajectories and models.

Description: 〈jats:p〉Abstract. The spatial and temporal variability of a low-centred polygon on the eastern floodplain area of the lower Anabar River (72.070° N, 113.921° E, northern Yakutia, Siberia) has been investigated using a multi-method approach. The present-day vegetation in each square metre was analysed revealing a community of Larix shrubby Betula and Salix on the polygon rim, a dominance of Carex and Andromeda polifolia in the rim-to-pond transition zone, and a predominantly monospecific Scorpidium scorpioides coverage within the pond. The TOC content, TOC/TN ratio, grain-size, vascular plant macrofossils, moss remains, diatoms, and pollen were analysed for two vertical sections and a sediment core from a transect across the polygon. Radiocarbon dating indicates that the formation of the polygon started at least 1500 yr ago; the general positions of the pond and rim have not changed since that time. Two types of pond vegetation were identified, indicating two contrasting development stages of the polygon. The first was a well-established moss association dominated by submerged or floating Scorpidium scorpioides and/or Drepanocladus spp. and overgrown by epiphytic diatoms such as Tabellaria flocculosa and Eunotia taxa. This stage coincides temporally with a period in which the polygon was only drained by lateral subsurface water flow, as indicated by mixed grain sizes. A different moss association occurred during times of repeated river flooding (indicated by homogeneous medium-grained sand that probably accumulated during the annual spring snow melt), characterized by an abundance of Meesia triquetra and a dominance of benthic diatoms (e.g. Navicula vulpina), indicative of a relatively high pH and a high tolerance of disturbance. A comparison of the local polygon vegetation (inferred from moss and macrofossil spectra) with the regional vegetation (inferred from pollen spectra) indicated that the moss association with Scorpidium scorpioides became established during relatively favourable climatic conditions while the association dominated by Meesia triquetra occurred during periods of harsh climatic conditions. Our study revealed a strong riverine influence (in addition to climatic influences) on polygon development and the type of peat accumulated. 〈/jats:p〉

Description: Climate change is destabilizing permafrost landscapes, affecting infrastructure, ecosystems, and human livelihoods. The rate of permafrost thaw is controlled by surface and subsurface properties and processes, all of which are potentially linked with each other. However, no standardized protocol exists for measuring permafrost thaw and related processes and properties in a linked manner. The permafrost thaw action group of the Terrestrial Multidisciplinary distributed Observatories for the Study of the Arctic Connections (T-MOSAiC) project has developed a protocol, for use by non-specialist scientists and technicians, citizen scientists, and indigenous groups, to collect standardized metadata and data on permafrost thaw. The protocol introduced here addresses the need to jointly measure permafrost thaw and the associated surface and subsurface environmental conditions. The parameters measured along transects include: snow depth, thaw depth, vegetation height, soil texture, and water level. The metadata collection includes data on timing of data collection, geographical coordinates, land surface characteristics (vegetation, ground surface, water conditions), as well as photographs. Our hope is that this openly available dataset will also be highly valuable for validation and parameterization of numerical and conceptual models, and thus to the broad community represented by the T-MOSAiC project.