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  • 1
    Publikationsdatum: 2024-05-30
    Beschreibung: Past vegetation, fire, and climate dynamics, as well as human impact, have been reconstructed for the first time in the highlands of the Gilan province in the Alborz mountains (above the Hyrcanian forest) for the last 4,300 cal yrs bp. Multi-proxy analysis, including pollen, spores, non-pollen palynomorphs, charcoal, and geochemical analysis, has been applied to investigate the environmental changes at 2,280 m a.s.l., above the Hyrcanian forest. Dominant steppe vegetation occurred in the study area throughout the recorded period. The formation of the studied mire deposits, as well as vegetation composition, suggest a change to wetter climatic conditions after 4,300 until 1,700 cal yrs bp. Fires were frequent, which may imply long-lasting anthropogenic activities in the area. Less vegetation cover with a marked decrease of the Moisture Index (MI) suggests drier conditions between 1,700 and 1,000 cal yrs bp. A high proportion of Cichorioideae and Amaranthaceae, as well as the reduction of trees, in particular Fagus and Quercus, at lower elevations, indicate human activities such as intense livestock grazing and deforestation. Soil erosion as the result of less vegetation due to dry conditions and/or human activities can be reconstructed from a marked increase of Glomus spores and high values of K and Ti. Since 1,000 cal yrs bp, the increasing MI, as well as the rise of Poaceae and Cyperaceae together with forest recovery, suggest a change to wetter conditions. The occurrence of still frequent Cichorioideae and Plantago lanceolata along with Sordaria reflect continued intense grazing of livestock by humans.
    Beschreibung: Deutsche Forschungsgemeinschaft (DE)
    Beschreibung: Georg-August-Universität Göttingen (1018)
    Schlagwort(e): ddc:561 ; Late Holocene ; Northern Iran ; Multi-proxy studies ; Hyrcanian mountain vegetation ; Climate change ; Human impact
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 2024-05-30
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The Intertropical Convergence Zone (ITCZ) is a central component of the atmospheric general circulation, but remarkably little is known about the dynamical and thermodynamical structure of the convergence zone itself. This is true even for the structure of the low‐level convergence that gives the ITCZ its name. Following on from the major international field campaigns in the 1960s and 1970s, we performed extensive atmospheric profiling of the Atlantic ITCZ during a ship‐based measurement campaign aboard the research vessel 〈italic toggle="no"〉SONNE〈/italic〉 in summer 2021. Combining data collected during our north–south crossing of the ITCZ with reanalysis data shows the ITCZ to be a meridionally extended region of intense precipitation, with enhanced surface convergence at its edges rather than in the center. Based on the location of these edges, we construct a composite view of the structure of the Atlantic ITCZ. The ITCZ, far from being simply a region of enhanced deep convection, has a rich inner life, that is, a rich dynamical and thermodynamic structure that changes throughout the course of the year, and has a northern edge that differs systematically from the southern edge.〈/p〉
    Beschreibung: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Beschreibung: Horizon 2020 Framework Programme CONSTRAIN http://dx.doi.org/10.13039/100010661
    Beschreibung: https://doi.org/10.5281/ZENODO.7051674
    Beschreibung: https://doi.org/10.24381/cds.adbb2d47
    Schlagwort(e): ddc:551.5 ; ITCZ ; Atlantic ; convergence ; observations ; reanalysis
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Publikationsdatum: 2024-05-30
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Mass transfer across the crust‐mantle boundary is a fundamental process governing planetary differentiation, the evolution of geochemical reservoirs and ore formation, controlled by physicochemical conditions at the crust‐mantle interface. In situ trace‐element, clinopyroxene 〈sup〉87〈/sup〉Sr/〈sup〉86〈/sup〉Sr and garnet Fe〈sup〉3+〈/sup〉/ΣFe of kimberlite‐borne eclogite xenoliths from the deep (∼50 km) crust‐mantle transition below the ca. 1.2–1.0 Ga Namaqua‐Natal Fold Belt (southwestern Kaapvaal craton margin) were determined to elucidate their origin and evolution, and to constrain the oxygen fugacity of this pivotal but largely inaccessible environment. Based on a garnet source signature (NMORB‐normalized Er/Lu > 1) in pristine “gabbroic” eclogites with pronounced positive Eu, Sr, and Pb anomalies, the suite is interpreted as originating as plagioclase‐rich cumulates in oceanic crust from melts generated beneath mature oceanic lithosphere, subsequently subducted during the Namaqua‐Natal orogeny. Enriched eclogites have higher measured 〈sup〉87〈/sup〉Sr/〈sup〉86〈/sup〉Sr in clinopyroxene (up to 0.7054) than gabbroic ones (up to 0.7036), and show increasing bulk‐rock Li, Be and Pb abundances with increasing δ〈sup〉18〈/sup〉O in clinopyroxene, and muted Eu‐Sr‐Pb anomalies. These systematics suggest interaction with a siliceous fluid sourced from seawater‐altered oceanic sediment in a subduction mélange setting. Garnet Fe〈sup〉3+〈/sup〉/ΣFe in deep crustal eclogites is extremely low (0.01–0.04, ±0.01 1〈italic〉σ〈/italic〉), as inherited from the plagioclase‐rich cumulate protolith, and owing to preferred partitioning into clinopyroxene at low temperatures (∼815–1000°C). Average maximum oxygen fugacities (∆logƒO〈sub〉2〈/sub〉(FMQ) = −3.1 ± 1.0 to −0.5 ± 0.7 relative to the Fayalite‐Magnetite‐Quartz buffer) are higher than in deeper‐seated on‐craton eclogite xenoliths, but mostly below sulfate stability, limiting the role of S〈sup〉6+〈/sup〉 species in oxidizing the mantle wedge.〈/p〉
    Beschreibung: Plain Language Summary: Subduction zones represent the main interface between Earth's surface and its deep interior. Metamorphic reactions during subduction cause fluid or melt loss from seawater‐altered oceanic crust and sediment, which enriches the overlying mantle, and possibly oxidizes it. This would explain why the mantle sources of subduction zone magmas appear to be more oxidized than in other tectonic settings. However, the details of the mass transfer in this deep environment are difficult to constrain because it is inaccessible. Using rare deep‐seated magmas (kimberlites) as probes of a ca. 1.2 billion year old southern African subduction zone, we investigated eclogite fragments that originated as subducted oceanic crust and were much later plucked from the wallrocks by the ascending magma. These eclogites show elemental and isotopic signatures of interaction with subducted sediments, pointing to mingling processes similar to those observed in modern subduction zones. We also estimated their oxygen fugacity, a measure of the chemical potential of oxygen. We find that sulfur, which has been implicated in mantle oxidation, would have only been stable in these rocks in its reduced form, making even seawater‐altered eclogites sinks rather than sources of oxygen, with implications for the transfer of sulfur‐loving metals across the mantle‐to‐crust‐boundary.〈/p〉
    Beschreibung: Key Points: 〈list list-type="bullet"〉 〈list-item〉 〈p xml:lang="en"〉Eclogite xenoliths sampling deep crust‐mantle transition below Namaqua‐Natal Fold Belt have plagioclase‐rich oceanic protoliths〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉Enriched xenoliths show signatures of interaction with siliceous, subducted sediment‐derived fluids under shallow fore‐arc conditions〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉Fe〈sup〉3+〈/sup〉‐based eclogite oxybarometry with oxygen fugacities below sulfate stability limits the role of S〈sup〉6+〈/sup〉 species in mantle wedge oxidation〈/p〉〈/list-item〉 〈/list〉 〈/p〉
    Beschreibung: Deutsche Forschungsgemeinschaft
    Beschreibung: https://doi.org/10.60520/IEDA/113077
    Schlagwort(e): ddc:552.4 ; kimberlite‐borne eclogite xenoliths ; crust‐mantle transition ; subduction zone processes ; redox budget ; metallogeny ; mantle wedge oxidation
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Publikationsdatum: 2024-05-30
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The interaction of the northern Nazca and southwestern Caribbean oceanic plates with northwestern South America (NWSA) and the collision of the Panama‐Choco arc (PCA) have significant implications on the evolution of the northern Andes. Based on a quantitative kinematic reconstruction of the Caribbean and Farallon/Farallon‐derived plates, we reconstructed the subducting geometries beneath NWSA and the PCA accretion to the continent. The persistent northeastward migration of the Caribbean plate relative to NWSA in Cenozoic time caused the continuous northward advance of the Farallon‐Caribbean plate boundary, which in turn resulted in its progressive concave trench bending against NWSA. The increasing complexity during the Paleogene included the onset of Caribbean shallow subduction, the PCA approaching the continent, and the forced shallow Farallon subduction that ended in the fragmentation of the Farallon Plate into the Nazca and Cocos plates and the Coiba and Malpelo microplates by the late Oligocene. The convergence tectonics after late Oligocene comprised the accretional process of the PCA to NWSA, which evolved from subduction erosion of the forearc to collisional tectonics by the middle Miocene, as well as changes of convergence angle and slab dip of the Farallon‐derived plates, and the attachment of the Coiba and Malpelo microplates to the Nazca plate around 9 Ma, resulting in a change of convergence directions. During the Pliocene, the Nazca slab broke at 5.5°N, shaping the modern configuration. Overall, the proposed reconstruction is supported by geophysical data and is well correlated with the magmatic and deformation history of the northern Andes.〈/p〉
    Beschreibung: Plain Language Summary: The tectonic reconstruction in convergent triple junctions is a particularly challenging task as the relative motion between plates could define highly changing boundaries. Indeed, the resulting interaction between these convergent plates may induce important changes in the disposition of the trenches, and in turn in the three‐dimensional geometry of the subducting plates. Therefore, these highly dynamic conditions throughout geological time may be accommodated by different phases of plate fragmentation and reorganization. These factors could explain the complex spatial‐temporal distribution of subduction‐related magmatism and the different episodes of deformation in the upper plates. This reasoning is validated in the northwestern corner of South America (SA), where the continent has been converging against the Caribbean and Farallon‐derived oceanic plates since Cretaceous time. Additionally, we study the effects of the collision and accretion of the Panama‐Choco arc with SA. To accomplish that, we review the kinematic history of the Farallon/Nazca and Caribbean oceanic plates relative to stable Guiana Craton (SA) and integrate these results with the magmatic and deformation evolution of the northern Andes, which allow us to propose a model of the geometrical evolution of the subducting slabs. The obtained model is additionally constrained by seismological data and published velocity anomalies.〈/p〉
    Beschreibung: Key Points: 〈list list-type="bullet"〉 〈list-item〉 〈p xml:lang="en"〉The tectonics of convergent triple junctions is complicated by the relative plate motion and interaction of the involved plates〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉We propose a model for the kinematic and geometric evolution of the Farallon/Nazca and Caribbean plates throughout the Cenozoic〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉The interaction between the Caribbean, Nazca and South American plates is closely related to the deformation history in the Northern Andes〈/p〉〈/list-item〉 〈/list〉 〈/p〉
    Beschreibung: Helmholtz‐Zentrum Potsdam‐Deutsches GeoForschungsZentrum GFZ http://dx.doi.org/10.13039/501100010956
    Beschreibung: Ecopetrol
    Beschreibung: https://doi.org/10.5281/zenodo.7411340
    Beschreibung: https://doi.org/10.5281/zenodo.8129751
    Schlagwort(e): ddc:551.8 ; plate kinematics ; convergent margins ; slab geometry ; Northern Andean deformation episodes
    Sprache: Englisch
    Materialart: doc-type:article
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  • 5
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    Unbekannt
    Landesamt für Geologie und Bergbau Rheinland-Pfalz
    Publikationsdatum: 2024-05-30
    Beschreibung: Ob Energiewende, die Gewinnung geothermischer Energie aus dem Boden, der Bau von unterirdischen Stromtrassen oder die Modellierung des Energiehaushalts der Erdoberfläche – die Kenntnisse der physikalisch-thermischen Eigenschaften des oberflächennahen Untergrundes sind von zentraler Bedeutung für zahlreiche Fragestellen der angewandten Bodenkunde. Böden als 3-Phasengemische aus Wasser, Luft und Festsubstanz können erhebliche Unterschiede und Differenzierungen bezüglich der thermischen Eigenschaften aufweisen. Neben dem Wasser- und Lufthaushalt sind Lagerungsdichte, Textur sowie die mineralogische Zusammensetzung entscheidende Einflussfaktoren. Auf Basis dieser Grundlagen wurden von verschiedenen Autoren Modellansätze entwickelt, um thermische Parameter bei unterschiedlichen Feuchtezuständen abzuleiten. Die meisten dieser Ansätze beruhen auf der Auswertung von repräsentativen Bodenproben, die ein möglichst breites Texturspektrum abbilden sollen. Die vorliegende Untersuchung verfolgt einen alternativen Ansatz. Durch Messungen im Routinebetrieb eines bodenphysikalischen Labors wurde ein umfangreicher Datensatz aufgebaut, der Auswertungen nach verschiedenen laboranalytischen sowie boden- und substratsystematischen Aspekten ermöglicht. Auf dieser breiten Datenbasis sollen die thermischen Eigenschaften von Böden bei definierten Randbedingungen noch genauer gefasst werden. Darüber hinaus sollen Grundlagen erarbeitet werden, die es ermöglichen, thermische Kennwerte über die Kenntnis einfacher Feldparameter möglichst präzise abzuschätzen.
    Beschreibung: research
    Schlagwort(e): ddc:631.436 ; Bodenphysik ; Wärmeleitfähigkeit ; Rheinland-Pfalz
    Sprache: Deutsch
    Materialart: doc-type:book , publishedVersion
    Format: 56
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  • 6
    Publikationsdatum: 2024-05-30
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Deep‐ploughing far beyond the common depth of 30 cm was used more than 50 years ago in Northern Germany with the aim to break root‐restricting layers and thereby improve access to subsoil water and nutrient resources. We hypothesized that effects of this earlier intervention on soil properties and yields prevailed after 50 years. Hence, we sampled two sandy soils and one silty soil (Cambisols and a Luvisol) of which half of the field had been deep‐ploughed 50 years ago (soils then re‐classified as Treposols). The adjacent other half was not deep‐ploughed and thus served as the control. At all the three sites, both deep‐ploughed and control parts were then conventionally managed over the last 50 years. We assessed yields during the dry year 2019 and additionally in 2020, and rooting intensity at the year of sampling (2019), as well as changes in soil structure, carbon and nutrient stocks in that year. We found that deep‐ploughing improved yields in the dry spell of 2019 at the sandy sites, which was supported by a more general pattern of higher NDVI indices in deep‐ploughed parts for the period from 2016 to 2021 across varying weather conditions. Subsoil stocks of soil organic carbon and total plant‐available phosphorus were enhanced by 21%–199% in the different sites. Root biomass in the subsoil was reduced due to deep‐ploughing at the silty site and was increased or unaffected at the sandy sites. Overall, the effects of deep‐ploughing were site‐specific, with reduced bulk density in the buried topsoil stripes in the subsoil of the sandy sites, but with elevated subsoil density in the silty site. Hence, even 50 years after deep‐ploughing, changes in soil properties are still detectable, although effect size differed among sites.〈/p〉
    Beschreibung: BonaRes http://dx.doi.org/10.13039/501100022576
    Schlagwort(e): ddc:631.4 ; aggregates ; carbon sequestration ; deep‐ploughing ; macronutrients ; subsoil ; Treposol
    Sprache: Englisch
    Materialart: doc-type:article
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  • 7
    Publikationsdatum: 2024-05-30
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The interpretation of stalagmite δ〈sup〉18〈/sup〉O in terms of reflecting Asian summer monsoon (ASM) precipitation is still elusive. Here, we present high‐resolution stalagmite trace element ratios (X/Ca, X = Mg, Sr, Ba) records from southwest China covering 116.09 to 4.07 ka BP. δ〈sup〉18〈/sup〉O, δ〈sup〉13〈/sup〉C, and X/Ca values exhibit clear precessional cycles, with δ〈sup〉18〈/sup〉O values reflecting ASM circulation/intensity, while X/Ca ratios capture local precipitation or evapotranspiration variations. Our results show that Northern Hemisphere summer insolation (NHSI) is the main driver of ASM intensity and precipitation phase variation, but global ice volume modulates the response magnitude of summer precipitation to insolation. During the Last Glacial Maximum, high ice volumes caused significant monsoon precipitation to decrease. In contrast to modern observations of the tripolar distribution of precipitation in China, our record is consistent with paleo‐precipitation records in southern and northern China.〈/p〉
    Beschreibung: Plain Language Summary: While it is well known that global changes have led to variations in the intensity and spatial distribution of Asian monsoon precipitation, the mechanisms behind this are not well understood. Paleoclimate records are essential for revealing the drivers behind monsoon variation. However, speleothem records from the Asian monsoon region rarely provide direct information on the amount of rainfall. Here we report on multiple indicator data sets from a stalagmite in southwestern China. It could help explore the variation of monsoon precipitation over the last ∼100,000 years. We find that the increase/decrease of Northern Hemisphere summer insolation controls the increase/decrease of Asian summer monsoon rainfall. In addition, global ice volume moderates the magnitude of rainfall response to insolation, and precipitation decreases significantly during high ice volume periods. Based on the present paleo‐precipitation records evidence, the existence of the spatial pattern of increasing/decreasing rainfall in central China corresponding to decreasing/increasing rainfall in northern and southern China remains ambiguous on the orbital scales, although the feature has been captured by some of the model simulations.〈/p〉
    Beschreibung: Key Points: 〈list list-type="bullet"〉 〈list-item〉 〈p xml:lang="en"〉Stalagmite trace elements are indicators of regional hydrological environmental variations in Southwestern China〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉Northern Hemisphere summer insolation and global ice volume modulate the phase and amplitude variations of regional hydrological environment〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉The meridional tripolar spatial pattern of precipitation in monsoon region in China on the orbital scale remains ambiguous〈/p〉〈/list-item〉 〈/list〉 〈/p〉
    Beschreibung: German Science Grant
    Beschreibung: Structure and Innovation Fund of the Region of Baden Württemberg
    Beschreibung: China Scholarship Council http://dx.doi.org/10.13039/501100004543
    Beschreibung: National Nature Science Foundation of China
    Beschreibung: Yunnan Fundamental Research Projects
    Beschreibung: Young and Middle‐age Academic and Technical Leader in Yunnan Province
    Beschreibung: https://doi.org/10.5281/zenodo.10072475
    Schlagwort(e): ddc:551 ; stalagmite ; trace elements ; Asian summer monsoon ; Northern Hemisphere summer insolation ; global ice volume ; regional hydrological environment
    Sprache: Englisch
    Materialart: doc-type:article
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  • 8
    Publikationsdatum: 2024-05-30
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
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  • 9
    Publikationsdatum: 2024-05-30
    Beschreibung: The toxin-producing dinoflagellate Alexandrium pseudogonyaulax has become increasingly abundant in northern European waters, replacing other Alexandrium species. A. pseudogonyaulax produces goniodomins and lytic substances, which can be cytotoxic toward other organisms, including fish, but we still know little about the environmental conditions influencing its growth and toxicity. Here, we investigated the impacts of different nitrogen sources and light intensities, common bottom-up drivers of bloom formation, on the growth and toxin content of three A. pseudogonyaulax strains isolated from the Danish Limfjord. While the growth rates were significantly influenced by nitrogen source and light intensity, the intracellular toxin contents only showed strong differences between the exponential and stationary growth phases. Moreover, the photophysiological response of A. pseudogonyaulax showed little variation across varying light intensities, while light-harvesting pigments were significantly more abundant under low light conditions. This study additionally highlights considerable physiological variability between strains, emphasizing the importance of conducting laboratory experiments with several algal strains. A high physiological plasticity toward changing abiotic parameters points to a long-term establishment of A. pseudogonyaulax in northern European waters.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
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  • 10
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    Cambridge University Press (CUP)
    In:  EPIC3Annals of Glaciology, Cambridge University Press (CUP), pp. 1-1, ISSN: 0260-3055
    Publikationsdatum: 2024-05-30
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Other , notRev
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  • 11
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    In:  EPIC3Proceedings of the COMNAP Symposium 2023 Antarctic Innovations and Collaborations, Council of Managers of National Antarctic Programs
    Publikationsdatum: 2024-05-30
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Conference , notRev
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  • 12
    Publikationsdatum: 2024-05-30
    Beschreibung: Model reconstruction of past ice dynamic changes are essential for our understanding of future ice sheet responses to climate change. However, paleo ice sheet model studies are poorly constrained as spatiotemporal coverage of proxy reconstructions are sparse. Previously, we showed, that it is possible to identify or exclude past ice sheet instabilities by using the isotopic record and age structure of a deep ice core in vicinity to dynamic outlet sectors as a constraint for flow parameterizations in an ice sheet model. Here, we highlight key Antarctic ice sheet domains in which deep ice cores in concert with radar observations of the ice sheet’s stratigraphy hold great potential to provide an even more rigid observational tuning target for ice flow models. In some of these regions dated deep ice cores are already available, often including coverage of internal reflection horizons potentially connecting the ice core age structure with faster flowing outlet sectors. In other regions either an ice core providing age constraints or radar observations are not yet available. We discuss the potential of ice core/stratigraphically calibrated ice flow modelling of dynamic Antarctic drainage systems. Furthermore, we present first model estimates of the age structure in these regions and identify promising sites for future ice coring expeditions or ice penetrating radar missions.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Conference , NonPeerReviewed
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  • 13
    Publikationsdatum: 2024-05-30
    Beschreibung: 〈jats:p〉Abstract. Stable water isotopes stored in snow, firn and ice are used to reconstruct climatic parameters. The imprint of these parameters at the snow surface and their preservation in the upper snowpack are determined by a number of processes influencing the recording of the environmental signal. Here, we present a dataset of approximately 3800 snow samples analysed for their stable water isotope composition, which were obtained during the summer season next to the deep drilling site of the East Greenland Ice Core Project in northeast Greenland (75.635411° N, 36.000250° W). Sampling was carried out every third day between 14 May and 3 August 2018 along a 39 m long transect. Three depth intervals in the top 10 cm were sampled at 30 positions with a higher resolution closer to the surface (0–1 and 1–4 cm depth vs. 4–10 cm). The sample analysis was carried out at two renowned stable water isotope laboratories that produced isotope data with the overall highest uncertainty of 0.09 ‰ for δ18O and 0.8 ‰ for δD. This unique dataset shows the strongest δ18O variability closest to the surface, damped and delayed variations in the lowest layer, and a trend towards increasing homogeneity towards the end of the season, especially in the deepest layer. Additional information on the snow height and its temporal changes suggests a non-uniform spatial imprint of the seasonal climatic information in this area, potentially following the stratigraphic noise of the surface. The data can be used to study the relation between snow height (changes) and the imprint and preservation of the isotopic composition at a site with 10–14 cm w.e. yr−1 accumulation. The high-temporal-resolution sampling allows additional analyses on (post-)depositional processes, such as vapour–snow exchange. The data can be accessed at https://doi.org/10.1594/PANGAEA.956626 (Zuhr et al., 2023a). 〈/jats:p〉
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
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  • 14
    Publikationsdatum: 2024-05-30
    Beschreibung: The toxin-producing dinoflagellate Alexandrium pseudogonyaulax has become increasingly abundant in northern European waters, replacing other Alexandrium species. A. pseudogonyaulax produces goniodomins and lytic substances, which can be cytotoxic toward other organisms, including fish, but we still know little about the environmental conditions influencing its growth and toxicity. Here, we investigated the impacts of different nitrogen sources and light intensities, common bottom-up drivers of bloom formation, on the growth and toxin content of three A. pseudogonyaulax strains isolated from the Danish Limfjord. While the growth rates were significantly influenced by nitrogen source and light intensity, the intracellular toxin contents only showed strong differences between the exponential and stationary growth phases. Moreover, the photophysiological response of A. pseudogonyaulax showed little variation across varying light intensities, while light-harvesting pigments were significantly more abundant under low light conditions. This study additionally highlights considerable physiological variability between strains, emphasizing the importance of conducting laboratory experiments with several algal strains. A high physiological plasticity toward changing abiotic parameters points to a long-term establishment of A. pseudogonyaulax in northern European waters.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
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  • 15
    Publikationsdatum: 2024-05-30
    Beschreibung: The subglacial landscape of Antarctica records and influences the behaviour of its overlying ice sheet. However, in many places, the evolution of the landscape and its control on ice sheet behaviour have not been investigated in detail. Using recently released radio-echo sounding data, we investigate the subglacial landscape of the Evans–Rutford region of West Antarctica. Following quantitative analysis of the landscape morphology under ice-loaded and ice-unloaded conditions, we identify 10 flat surfaces distributed across the region. Across these 10 surfaces, we identify two distinct populations based on clustering of elevations, which potentially represent remnants of regionally coherent pre-glacial surfaces underlying the West Antarctic Ice Sheet (WAIS). The surfaces are bounded by deeply incised glacial troughs, some of which have potential tectonic controls. We assess two hypotheses for the evolution of the regional landscape: (1) passive-margin evolution associated with the break-up of the Gondwana supercontinent or (2) an extensive planation surface that may have been uplifted in association with either the West Antarctic Rift System or cessation of subduction at the base of the Antarctic Peninsula. We suggest that passive-margin evolution is the most likely of these two mechanisms, with the erosion of glacial troughs adjacent to, and incising, the flat surfaces likely having coincided with the growth of the WAIS. These flat surfaces also demonstrate similarities to other identified surfaces, indicating that a similar formational process may have been acting more widely around the Weddell Sea embayment. The subsequent fluctuations of ice flow, basal thermal regime, and erosion patterns of the WAIS are therefore controlled by the regional tectonic structures.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
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  • 16
    Publikationsdatum: 2024-05-30
    Beschreibung: The strategic ambition is to develop an operational, comprehensive, and resourced system that delivers priority observations and information to guide mitigation and adaptation responses to climate change, sustains ocean health within a sustainable blue economy, and facilitates informed decision-making for science, business and society. Such a system is envisioned to be co-designed, fit-for-purpose, multidisciplinary, geographically expanded, responsive, and sustainable in time, delivering ocean observations to all nations and users, prioritising societal needs. Transforming ocean observations into accessible information will require integration across disciplines, across national observing systems, along the value chain, and across stakeholders. Innovative technology approaches and a diversified set of actors and approaches will be required for success. The Global Ocean Observing System (GOOS) of IOC UNESCO can provide the implementation framework for Challenge 7 and the UN Ocean Decade provides the opportunity and vehicle for transformation. Five recommendations have been identified to fulfil the strategic ambition of Ocean Decade Challenge 7. Act now on known observational needs. Upgrade and expand ocean observing capacity in poorly-observed areas such as polar regions, island nations and territories, coastal areas of developing nations, coastal systems that are rapidly changing, and the under-observed deep ocean. Thematic priorities for ocean observing by 2030 should focus on key climate risk and adaptation needs, extreme events, coastal services for ocean management, ocean carbon, marine pollution, biogeochemistry, and biodiversity. Adopt new economic thinking. Establish new and sustained financing mechanisms for global ocean observing, including resourcing for Small Island Developing States (SIDS) and Least Developed Countries (LDCs). Use economic models for ocean investment to diversify and accelerate investment in ocean observing and infrastructure from new actors. Partnerships are key. Increase national, regional and global coordination, focusing on co-design and partnerships. Improved coordination that uses the GOOS framework to ensure standards, best practices for a sustainably expanded GOOS. Diversify partnerships across sectors (economic, public, private, and philanthropic) and embrace the abilities and needs of the different stakeholders to co-design, co-develop, and co-deliver observations that translate into the information required by these sectors. Technology and innovation will be a pillar. Integrate and harmonise observations across observing platforms (in situ, satellite, emerging networks). Develop innovative in situ, autonomous and cost-effective technologies to maximise reach, ensuring standardisation and best practices. Technology barriers still need to be lowered to ensure everyone has equitable access to observing technology and has the ability to use these assets. Artificial Intelligence (AI) and Machine Learning (ML) tools will provide user-ready information from integrated observations to democratise information for users. Expanded, capable, and diversified workforce. Expand and diversify the workforce of skilled and trained ocean professionals. Training and capacity development will be critical across the observing ‘ecosystem’ outlined in the Framework for Ocean Observing (FOO), from data collection to data analysis and modelling, and for data use and application.
    Beschreibung: Published
    Beschreibung: Refereed
    Schlagwort(e): Ocean observation ; GOOS ; Global Ocean Observing System ; Ocean observing
    Repository-Name: AquaDocs
    Materialart: Report
    Format: 22pp.
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  • 17
    Publikationsdatum: 2024-05-30
    Beschreibung: By 2030, the success of Ocean Decade Challenge No.1 ‘Understand and Beat Marine Pollution’ will be demonstrated by the generation of scientifically sound data enabling a holistic understanding of the extent and impact of pollution across the land-ocean continuum, thereby supporting the achievement of a cleaner and healthier ocean where all ecosystems and their inhabitants thrive free from the impacts of marine pollution, allowing for their full functioning and service provision. This success will be based on completion of a comprehensive review of all available evidence about marine pollution, including an analysis of data gaps and the development and implementation of strategies for filling those gaps, as well as a comprehensive analysis of solutions for addressing and preventing the negative effects of marine pollution. Achieving this success will require knitting together existing and new data sets using AI and other technologies, identifying priority pollutants and areas for action, and providing globally consistent monitoring, data collection, storage and sharing protocols. Success will further be demonstrated through the establishment of new connections and partnerships among users across the public - private spectrum that lead to the funding, development and implementation of new technologies and projects aimed at monitoring, controlling, reducing, and/or mitigating marine pollution from any source, including the creation and sustainability of a global network of strategically positioned sentinel stations and regional laboratory hubs for sustained, long-term monitoring of marine pollution. Success will include fulfilment of the following critical knowledge gaps: • a comprehensive and holistic understanding of the impacts of priority pollutants (e.g., pollutants found or expected to emerge in high concentrations, or with high toxicity, or with significant adverse effects on biota or human health) across the land to ocean continuum; • a better understanding of the sources, sinks, fate and impacts of all pollutants, including the pollutants of emerging concern; • improved knowledge on the distribution and impacts of marine pollution, particularly in the Global South and deep ocean waters, which currently represent the largest geographical gaps. and the following priority datasets gaps: • long-term time series of marine pollutants; • baseline and toxicity data of pollutants across the land-ocean continuum; • data on the impacts of the co-occurrence of multiple pollutants; • data on the effects of climate change on the toxicity, bioavailability and impacts of multiple co-existent pollutants. • It will include development of: • a global network of strategically positioned sentinel stations for continuous, long-term monitoring; • cost-effective, real-time monitoring systems and technologies for tracking pollutant sources, distribution, and transfers across the land-ocean continuum; • a global network of regional laboratory hubs focused on generating high-quality data, promoting capacity building and facilitating technology transfer; • training programs on harmonized protocols for the acquisition, reporting and recording of quality-controlled data on marine pollution; • environmentally robust new technologies and processes for the control and mitigation of marine pollution.
    Beschreibung: Published
    Beschreibung: Refereed
    Schlagwort(e): Marine pollution ; Pollutants ; Ocean health
    Repository-Name: AquaDocs
    Materialart: Report
    Format: 27pp.
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  • 18
    Publikationsdatum: 2024-05-30
    Beschreibung: Challenge 9 aims to ensure comprehensive capacity development and equitable access to data, information, knowledge, technology, and participatory decision-making across all aspects of ocean science and for all stakeholders. It is based on the understanding that everyone has something to contribute through shared knowledge, resources, ideas, or partnerships. Challenge 9 therefore is focused on equity and justice in access to capacity, resources, and decision making. By 2030, success for Ocean Decade Challenge 9 will be reached when: Technical, transdisciplinary, and transversal skills required by scientists, resource users, educators, communicators, managers, and policymakers, to deliver the Decade’s challenges, are strengthened and evenly distributed with an emphasis on least developed countries (LDCs) and Small Island Developing States (SIDS) and other under-represented groups. Funding mechanisms, multi-directional partnerships, multi-directional partnerships, infrastructure, and technology required to deliver the Decade’s challenges across regions and communities are enhanced and evenly distributed with emphasis on promoting access to LDCs and SIDS and on promoting greater cooperation between regions. Users and stakeholders from currently under-represented groups (i.e., women; ECOPs; Indigenous communities; LDCs and SIDS; people with disabilities; and others) are well-represented and participatory in ocean science, communication, management, decision making, and policy within the Decade framework. Wider promotion of ethically-driven actions and access to open-source software, ocean data, knowledge, and information among different users of the ocean has been achieved, and language barriers/restrictions have been mediated, including sharing knowledge in forms that are well articulated by non-scientific audiences. Recognition for Indigenous and local knowledge and traditional beliefs that promote conservation receives backing by the Decade and is integrated into all the Decade challenges. Success will include fulfilment of the following critical capacity development needs: skills enhancement; representation and meaningful participation; equitable funding; infrastructure; technology; access to data and information; publishing of research findings; better representation of scientists and knowledge from LDCs, SIDS and other under-represented groups in international publications and decision-making bodies and procedures; and promotion of the use of multiple languages in ocean science communication.
    Beschreibung: Published
    Beschreibung: Refereed
    Schlagwort(e): Capacity development ; Under-represented groups ; Least Developed Countries (LDC) ; Equitable access ; Open access ; Small Island Developing States (SIDS)
    Repository-Name: AquaDocs
    Materialart: Report
    Format: 28pp.
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  • 19
    Publikationsdatum: 2024-05-30
    Beschreibung: By 2030, success for Ocean Decade Challenge No. 10 will be evidenced through a culture shift in the ocean community leading to implicit understanding that ocean threats are an outcome of human behaviour. This will require a shift in the way that ocean science, in the broad sense as defined in the Decade, is formulated, practiced, and communicated to ensure that all sectors of society have strengthened emotional connections with the ocean, and understand the vital role that the ocean plays in human and planetary well-being, including climate stability. All members of society across regions, sectors, and scales will have increased motivation, capability, and opportunity to make decisions and behave in ways that ensure a healthy ocean. By 2030, success for Ocean Decade Challenge No. 10 will include fulfilment of critical science and knowledge gaps: Increased priority and practice of science that embraces multiple knowledge systems and transdisciplinary collaboration Increased priority of Indigenous-led research, consistent with the supporting articles of the United Nations Declaration on the Rights of Indigenous Peoples (UNDRIP), inherent rights, and signed treaty obligations with Indigenous Nations Increased priority of marine social sciences, particularly: public perceptions ocean research marine citizenship and identity research behavioural science research linked to ocean-climate education and communications research on how ocean literacy can be measured and monitored over time, and the impacts of an ocean literate society on ocean health research on ocean literacy as a policy tool science communication through multiple approaches including immersive technology, storytelling, and the arts Success will also depend on the generation, sharing, and use of the following priority datasets: human-ocean connection/human-ocean values dataset(s) pro-ocean behaviour change methodologies, case studies, and effective practices impact mapping of regional and key global ocean literacy initiatives ocean culture mapping that includes a global body of evidence (contextual, local knowledge) that demonstrates and supports cultural engagement as an enabler of ocean-human health. It will include the development of: a co-designed theory of change to action key drivers of Challenge 10, in which regional expertise helps guide the initial and ongoing strategic direction of the newly launched Decade Coordinating Office (DCO), Connecting People and Ocean a guiding portfolio of best practices on research co-design, co-production, co-implementation, and co-evaluation, respectfully bridging different forms of knowledge, ensuring mutual recognition and benefits, and nurturing long-term relationships with each other and nature a collaborative global, multi-dimensional ocean literacy survey tool (i.e., Ocean & Society Survey) to measure ocean connection and values, as well as motivators, enablers, barriers to action and behaviour change a global network of ocean communications experts and regional ocean communications communities of practice to support training, accreditation, upskilling, knowledge exchange, and impact measurement a global network of ocean-climate education experts (formal, informal, and non-formal) to support teacher training, certification programmes, and knowledge exchange a Global Blue Schools Network, building off the All-Atlantic and European Blue Schools Networks, to bridge practitioner best practices with research and training a global framework for sharing successful community projects that demonstrate practices and solutions specific to cultural connections, heritage, language, and place-based innovations for ocean-human health.
    Beschreibung: Published
    Beschreibung: Refereed
    Schlagwort(e): Human activities ; Ocean health ; Indigenous knowledge ; Marine social sciences ; Ocean literacy ; Societal impact ; Science communication
    Repository-Name: AquaDocs
    Materialart: Report
    Format: 38pp.
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  • 20
    Publikationsdatum: 2024-05-30
    Beschreibung: Ocean Decade Challenge 8 of the United Nations Decade of Ocean Science for Sustainable Development 2021-2030 (the ‘Ocean Decade’) seeks to create an adaptive and dynamic digital representation of the ocean to make the ocean accessible to a broader community, to enhance decision-making and to support sustainable ocean management. While creating a comprehensive digital representation of the Ocean is the ultimate objective of Decade Challenge 8, the focus in this White Paper is on delivering concrete outcomes and the transformational change needed to create the enabling environment and initial digital content, by 2030, that will allow us to fully deliver on the ambitions of Challenge 8 on the longer term. An Implementation Plan (IP) for the Ocean Decade’s Data and Information Strategy is currently under development by the Data Strategy Implementation Group (DSIG). This IP will outline how data systems participating in the Ocean Decade can co-create a distributed, robust, and collaborative ‘digital ecosystem’ that leverages open, scalable, easily implementable, and responsive technologies and management solutions. An interoperable, distributed data and information sharing system must be both deployed and maintained to allow the realization of Challenge 8, addressing specific challenges such as data interoperability, accessibility, and inclusivity. Additionally, potential issues related to data privacy, cybersecurity, and equitable access to technological infrastructure should be addressed to ensure the comprehensive development of the strategic ambition. In developing the Strategic Ambition for Challenge 8, we consider the data and information needs and priorities identified by the other Decade Challenges and their working groups, as our primary users (and contributors), representing as they do the key sustainability challenges for the Decade, and encompassing all relevant stakeholders. Guided by the Decade’s ambition to ‘leave no one behind’ we recognize that this challenge must deliver outputs that are relevant and useful for the global ocean science community, and in fact by extension the widest possible range of users and stakeholders, including the eight billion people on this planet, who should be able to access and use what is delivered by the Decade in ways adapted to their needs and capacities, if so desired. By 2030, the Strategic Ambition for Ocean Decade Challenge 8 is to have in place the enabling environment for the creation of and access to an increasing number of digital representations and twin applications of the Ocean as well as the underpinning data and information needed to develop them, delivering at minimum 10 societally relevant 0global base-layers accessible via a global online Digital Atlas, complemented by a minimum of 10 local use cases (prioritizing SIDS and LDCs) to address challenges in using and contributing to the Decade’s distributed digital ecosystem and to demonstrate and stress test its relevance, effectiveness and inclusiveness.
    Beschreibung: Published
    Beschreibung: Refereed
    Schlagwort(e): Digital Twin of the Ocean ; Data visualisation ; Digital representations ; Digital atlas ; Federated Ocean Data Discovery Service ; Data products ; Ocean forecasting
    Repository-Name: AquaDocs
    Materialart: Report , Report , Report
    Format: 54pp.
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  • 21
    Publikationsdatum: 2024-05-30
    Beschreibung: By 2030, successful achievement of Ocean Decade Challenge No. 6 will require demonstrating substantial advancements within the global community towards enhancing their resilience to coastal and ocean hazards. This includes implementing two crucial elements: (1) establishing comprehensive 'people-centered' early warning systems capable of addressing multiple hazards, and (2) devising adaptation strategies that specifically target risks associated with the ocean, including those linked to climate change. These endeavours will play a pivotal role in guiding sustainable practices in ocean planning. Success will also hinge on addressing critical gaps in scientific understanding and knowledge across important components such as risk assessment and risk reduction, in addition to putting in place robust institutional mechanisms for implanting novel solutions that contribute to coastal resilience. Some key elements to be addressed in this context include: (i) gathering and generating observational and modelling datasets relevant to risk assessment, including downscaled climate scenarios for coastal regions, within robust data-sharing frameworks; (ii) promoting interdisciplinary and international research and innovation to tackle challenges comprehensively, with a focus on methodologies like Digital Twin approaches; (iii) improving standards for risk communication at both national and international levels; (iv) fostering partnerships at various scales involving local communities, public and private disaster risk reduction entities, governmental bodies, and academic institutions; (v) building capacity in research and communication to cultivate a shared understanding of coastal resilience strategies; and (vi) enhancing resilient infrastructure and promoting sustainable resource management along coastlines. It is imperative to establish partnerships with existing international UN programs dedicated to disaster risk reduction and coastal resilience. Strengthening connections with UN Decade Actions through Decade Coordination Offices and Decade Collaboration Centers is of utmost importance for effective coordination and collaboration. Based on the above strategic ambition it is also suggested that the formulation of the Ocean Decade Challenge could be modified as follows: Increase community resilience to ocean and coastal risks
    Beschreibung: Published
    Beschreibung: Refereed
    Schlagwort(e): Coastal resilience ; Coastal zone management ; Hazard warning system ; Risk assessement ; Ocean hazards
    Repository-Name: AquaDocs
    Materialart: Report
    Format: 37pp.
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  • 22
    Publikationsdatum: 2024-05-30
    Beschreibung: The State of the Ocean Report (StOR) has the ambition to inform policymakers about the state of the ocean and to stimulate research and policy actions towards ‘the ocean we need for the future we want’, contributing to the 2030 Agenda and in particular SDG 14, which reads ‘Conserve and sustainably use the oceans, seas and marine resources’, as well as other global processes such as the UNFCCC, the Convention on Biological Diversity and the Sendai Framework for Disaster Risk Reduction. Structured around the seven UN Decade of Ocean Science for Sustainable Development Outcomes, the Report provides important information about the achievements of the UN Ocean Decade and, in the longer term, about ocean well-being. The StOR will be used to inform policy and administrative priorities and identify research focus areas that need to be strengthened or developed.
    Beschreibung: Published
    Beschreibung: Refereed
    Schlagwort(e): Plastic pollution ; Ecosystem restoration ; Deoxygenation ; Blue carbon ecosystems ; Marine spatial planning (MSP) ; Sustainable production ; Sustainable food prduction ; Carbon dioxide ; Harmful algal blooms ; Global Ocean Observing System ; Data sharing ; ASFA_2015::P::Plastics ; ASFA_2015::A::Acidification ; ASFA_2015::G::Global warming ; ASFA_2015::C::Carbon
    Repository-Name: AquaDocs
    Materialart: Report
    Format: 92pp.
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  • 23
    Publikationsdatum: 2024-05-30
    Beschreibung: Large stratospheric balloons are the easiest access to near space. Large long duration balloons (LDBs) can float in the stratosphere for weeks collecting measurements (e.g., astrophysical or geophysical data) or samples (e.g., contaminants, volcanic ash, micrometeorites). The recovery of data media and samples is a common problem in this type of experiment because direct radio com-munication becomes useless when the balloon crosses the horizon, and satellite links are too slow and expensive. For this reason, physical recovery of the payload is mandatory to obtain experi-mental results, which is a difficult task, especially in polar regions. The goal of HERMES (HEmera Returning MESsenger) is to allow researchers to obtain experimental data prior to payload recovery. HERMES is a system equipped with an autonomous glider capable of physically transporting data and samples from the stratosphere to a recovery point on the ground. The glider is installed on the balloon payload via a remotely controlled release system and is connected to the main computer to store a copy of the scientific data and to receive the geographic coordinates of the recovery point. This allows scientists to obtain experimental results before recovering the payload. The article de-scribes HERMES and the first experimental flight of the entire system, which was conducted at Esrange Space Center (Kiruna, Sweden) in July 2022.
    Beschreibung: Published
    Beschreibung: 308
    Beschreibung: JCR Journal
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 24
    Publikationsdatum: 2024-05-30
    Beschreibung: Istituto Nazionale di Geofisica e Vulcanologia
    Beschreibung: Published
    Schlagwort(e): Present-day stress ; Borehole breakout ; Earthquake focal mechanism ; 04.07. Tectonophysics ; 04.06. Seismology ; 04.04. Geology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: web product
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  • 25
    Publikationsdatum: 2024-05-30
    Beschreibung: A new subgenus Peculiaripalpus subgen. nov. with a new species Partnunia (Peculiaripalpus) longlingensis sp. nov. which belongs to Partnunia Piersig, 1896 is described and illustrated. Partnunia represents a newly record genus of Protziinae Koenike, 1909 for Chinese fauna. The diagnosis of Partnunia is modified according to the new species. An updated key is provided for the subfamilies, genera and subgenera of Hydryphantidae.
    Schlagwort(e): water mites; new taxa; scanning electron microscope
    Repository-Name: National Museum of Natural History, Netherlands
    Materialart: info:eu-repo/semantics/article
    Format: application/pdf
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  • 26
    Publikationsdatum: 2024-05-30
    Beschreibung: X-ray micro–computed tomography (µCT) is increasingly used to record the skeletal growth banding of corals. However, the wealth of data generated is time consuming to analyse for growth rates and colony age. Here we test an artificial intelligence (AI) approach to assist the expert identification of annual density boundaries in small colonies of massive Porites spanning decades. A convolutional neural network (CNN) was trained with µCT images combined with manually labelled ground truths to learn banding-related features. The CNN successfully predicted the position of density boundaries in independent images not used in training. Linear extension rates derived from CNN-based outputs and the traditional method were consistent. In the future, well-resolved 2D density boundaries from AI can be used to reconstruct density surfaces and enable studies focused on variations in rugosity and growth gradients across colony 3D space. We recommend the development of a community platform to share annotated images for AI.
    Repository-Name: National Museum of Natural History, Netherlands
    Materialart: info:eu-repo/semantics/article
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  • 27
    Publikationsdatum: 2024-05-30
    Beschreibung: MtDNA barcoding is regularly applied to determine the provenance of invasive species. Variation in spatial genetic structuring across a species’ range, typically high within glacial refugia and low in postglacially colonized areas, influences the precision of this approach. The palmate newt (Lissotriton helveticus) has been introduced north of its native range inside the Netherlands. We conduct mtDNA barcoding to try and retrace the origin of the introduced localities. A large increase in sample size, particularly focusing on temperate Europe, emphasizes that the palmate newt shows practically no genetic variation outside the Iberian Peninsula glacial refugium. While we find a haplotype previously only known from the Iberian Peninsula inside the native range in Belgium, the haplotype present in the introduced Dutch populations occurs widely throughout the native range north of the Iberian Peninsula. Although mtDNA barcoding can be a powerful tool in invasion biology, the palmate newt case exposes its limitations.
    Schlagwort(e): amphibians ; invasive species ; Lissotriton helveticus ; mtDNA barcoding ; phylogeography.
    Repository-Name: National Museum of Natural History, Netherlands
    Materialart: info:eu-repo/semantics/other
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  • 28
    Publikationsdatum: 2024-05-30
    Beschreibung: In the present study, we compared mucus and gut-associated prokaryotic communities from seven nudibranch species with sediment and seawater from Thai coral reefs using high-throughput 16S rRNA gene sequencing. The nudibranch species were identified as Doriprismatica atromarginata (family Chromodorididae), Jorunna funebris (family Discodorididae), Phyllidiella nigra, Phyllidiella pustulosa, Phyllidia carlsonhoffi, Phyllidia elegans, and Phyllidia picta (all family Phyllidiidae). The most abundant bacterial phyla in the dataset were Proteobacteria, Tenericutes, Chloroflexi, Thaumarchaeota, and Cyanobacteria. Mucus and gut-associated communities differed from one another and from sediment and seawater communities. Host phylogeny was, furthermore, a significant predictor of differences in mucus and gut-associated prokaryotic community composition. With respect to higher taxon abundance, the order Rhizobiales (Proteobacteria) was more abundant in Phyllidia species (mucus and gut), whereas the order Mycoplasmatales (Tenericutes) was more abundant in D. atromarginata and J. funebris. Mucus samples were, furthermore, associated with greater abundances of certain phyla including Chloroflexi, Poribacteria, and Gemmatimonadetes, taxa considered to be indicators for high microbial abundance (HMA) sponge species. Overall, our results indicated that nudibranch microbiomes consisted of a number of abundant prokaryotic members with high sequence similarities to organisms previously detected in sponges.
    Repository-Name: National Museum of Natural History, Netherlands
    Materialart: info:eu-repo/semantics/article
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  • 29
    Publikationsdatum: 2024-05-30
    Beschreibung: A new tetramic acid glycoside, aurantoside L (1), was isolated from the sponge Siliquariaspongia japonica collected at Tsushima Is., Nagasaki Prefecture, Japan. The structure of aurantoside L (1) composed of a tetramic acid bearing a chlorinated polyene system and a trisaccharide part was elucidated using spectral analysis. Aurantoside L (1) showed anti-parasitic activity against L. amazonensis with an IC50 value of 0.74 μM.
    Schlagwort(e): aurantosides ; Siliquariaspongia japonica ; marine sponge ; nuclear magnetic resonance ; mass ; spectrometry ; anti-leishmanial activity ; marine natural products
    Repository-Name: National Museum of Natural History, Netherlands
    Materialart: info:eu-repo/semantics/article
    Format: application/pdf
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  • 30
    Publikationsdatum: 2024-05-30
    Beschreibung: Mitochondria originated from an ancient bacterial endosymbiont that underwent reductive evolution by gene loss and endosymbiont gene transfer to the nuclear genome. The diversity of mitochondrial genomes published to date has revealed that gene loss and transfer processes are ongoing in many lineages. Most well-studied eukaryotic lineages are represented in mitochondrial genome databases, except for the superphylum Retaria—the lineage comprising Foraminifera and Radiolaria. Using singlecell approaches, we determined two complete mitochondrial genomes of Foraminifera and two nearly complete mitochondrial genomes of radiolarians. We report the complete coding content of an additional 14 foram species. We show that foraminiferan and radiolarian mitochondrial genomes contain a nearly fully overlapping but reduced mitochondrial gene complement compared to other sequenced rhizarians. In contrast to animals and fungi, many protists encode a diverse set of proteins on their mitochondrial genomes, including several ribosomal genes; however, some aerobic eukaryotic lineages (euglenids, myzozoans, and chlamydomonas-like algae) have reduced mitochondrial gene content and lack all ribosomal genes. Similar to these reduced outliers, we show that retarian mitochondrial genomes lack ribosomal protein and tRNA genes, contain truncated and divergent small and large rRNA genes, and contain only 14 or 15 proteincoding genes, including nad1, -3, -4, -4L, -5, and -7, cob, cox1, -2, and -3, and atp1, -6, and -9, with forams and radiolarians additionally carrying nad2 and nad6, respectively. In radiolarian mitogenomes, a noncanonical genetic code was identified in which all three stop codons encode amino acids. Collectively, these results add to our understanding of mitochondrial genome evolution and fill in one of the last major gaps in mitochondrial sequence databases.
    Schlagwort(e): Foraminifera ; mitochondrial evolution ; mitochondrial genome ; Radiolaria ; Retaria ; Rhizaria
    Repository-Name: National Museum of Natural History, Netherlands
    Materialart: info:eu-repo/semantics/article
    Format: application/pdf
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  • 31
    facet.materialart.
    Unbekannt
    Universidade Estadual da Paraiba/Universidade Federal Rural de Pernambuco (Ethnobiology and Conservation)
    In:  Ethnobiology and Conservation vol. 13 no. 14
    Publikationsdatum: 2024-05-30
    Beschreibung: A cotton headdress ornamented with several botanical and faunal elements (TM-5074-2) is kept in the depot of the Wereldmuseum in Amsterdam. There is little information about the provenance of the object or its context of use. Identified by the museum as a ‘shaman hood’, is said to have been obtained from an Asháninka indigenous community along the Ene River, Peruvian Amazon. The unusual composition of the hood, with 16 bundles of bird fragments, 39 bundles of mammal parts, and 3332 seeds, raises several questions. Is the object a traditional Asháninka ornament? Is the combination of so many distinct elements a result of later additions? Is it possible that the hood was manufactured for sale? In addition to literature research, this study aimed to identify the plant and animal species linked to the hood, to verify whether the object in its current composition (covered with plant and animal ornaments) could have been made in the same region inhabited by the Asháninka communities. Through the morphological comparison of the plant and animal parts attached to the hood with the botanical and zoological collections of Naturalis Biodiversity Center, we could identify the species and trace their geographical occurrence. Eight different plant species, eight bird taxa, and at least eight mammal taxa attached to the object were identified, most of them native to the Peruvian Amazon. Finally, with the identification of the species, we proposed possible interpretations for the selection of plants and animals added to the shaman hood based on the historical context and the Asháninka worldview.
    Schlagwort(e): Museum objects ; Amazon ; Provenance Research ; Seed beads
    Repository-Name: National Museum of Natural History, Netherlands
    Materialart: info:eu-repo/semantics/article
    Format: application/pdf
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  • 32
    facet.materialart.
    Unbekannt
    Copernicus GmbH
    In:  Earth System Science Data vol. 13 no. 9, pp. 4313-4329
    Publikationsdatum: 2024-05-30
    Beschreibung: Marine Isotope Stage 5e (MIS 5e; the Last Interglacial, 125 ka) represents a process analog for a warmer world. Analysis of sea-level proxies formed in this period helps in constraining both regional and global drivers of sea-level change. In Southeast Asia, several studies have reported elevation and age information on MIS 5e sea-level proxies, such as fossil coral reef terraces or tidal notches, but a standardized database of such data was hitherto missing. In this paper, we produced such a sea-level database using the framework of the World Atlas of Last Interglacial Shorelines (WALIS; https://warmcoasts.eu/world-atlas.html). Overall, we screened and reviewed 14 studies on Last Interglacial sea-level indicators in Southeast Asia, from which we report 43 proxies (42 coral reef terraces and 1 tidal notch) that were correlated to 134 dated samples. Five data points date to MIS 5a (80 ka), six data points are MIS 5c (100 ka), and the rest are dated to MIS 5e. The database compiled in this study is available at https://doi.org/10.5281/zenodo.5040784 (Maxwell et al., 2021).
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  • 33
    Publikationsdatum: 2024-05-30
    Beschreibung: Mangrove forests provide valuable ecosystem services to coastal communities across tropical and subtropical regions. Current anthropogenic stressors threaten these ecosystems and urge researchers to create improved monitoring methods for better environmental management. Recent efforts that have focused on automatically quantifying the above-ground biomass using image analysis have found some success on high resolution imagery of mangrove forests that have sparse vegetation. In this study, we focus on stands of mangrove forests with dense vegetation consisting of the endemic Pelliciera rhizophorae and the more widespread Rhizophora mangle mangrove species located in the remote Utría National Park in the Colombian Pacific coast. Our developed workflow used consumer-grade Unoccupied Aerial System (UAS) imagery of the mangrove forests, from which large orthophoto mosaics and digital surface models are built. We apply convolutional neural networks (CNNs) for instance segmentation to accurately delineate (33% instance average precision) individual tree canopies for the Pelliciera rhizophorae species. We also apply CNNs for semantic segmentation to accurately identify (97% precision and 87% recall) the area coverage of the Rhizophora mangle mangrove tree species as well as the area coverage of surrounding mud and water land-cover classes. We provide a novel algorithm for merging predicted instance segmentation tiles of trees to recover tree shapes and sizes in overlapping border regions of tiles. Using the automatically segmented ground areas we interpolate their height from the digital surface model to generate a digital elevation model, significantly reducing the effort for ground pixel selection. Finally, we calculate a canopy height model from the digital surface and elevation models and combine it with the inventory of Pelliciera rhizophorae trees to derive the height of each individual mangrove tree. The resulting inventory of a mangrove forest, with individual P. rhizophorae tree height information, as well as crown shape and size descriptions, enables the use of allometric equations to calculate important monitoring metrics, such as above-ground biomass and carbon stocks.
    Schlagwort(e): mangrove forests ; forest inventory ; monitoring ; habitat mapping ; UAV ; UAS ; artificial ; intelligence ; machine learning ; instance segmentation ; semantic segmentation ; above ground biomass ; carbon stock
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  • 34
    Publikationsdatum: 2024-05-30
    Beschreibung: Foraminifera are a species-rich phylum of rhizarian protists that are highly abundant in most marine environments. Molecular methods such as metabarcoding have revealed a high, yet undescribed diversity of Foraminifera. However, so far only one molecular marker, the 18S ribosomal RNA, was available for metabarcoding studies on Foraminifera. Primers that allow amplification of foraminiferal mitochondrial cytochrome oxidase I (COI) and identification of Foraminifera species were recently published. Here we test the performance of these primers for the amplification of whole foraminiferal communities, and compare their performance to that of the highly degenerate LerayXT primers, which amplify the same COI region in a wide range of eukaryotes. We applied metabarcoding to 48 samples taken along three transects spanning a North Sea beach in the Netherlands from dunes to the low tide level, and analysed both sediment samples and meiofauna samples, which contained taxa between 42 mm and 1 mm in body size obtained by decantation from sand samples. We used single-cell metabarcoding (Girard et al., 2022) to generate a COI reference library containing 32 species of Foraminifera, and used this to taxonomically annotate our community metabarcoding data. Our analyses show that the highly degenerate LerayXT primers do not amplify Foraminifera, while the Foraminifera primers are highly Foraminifera- specific, with about 90% of reads assigned to Foraminifera and amplifying taxa from all major groups, i.e., monothalamids, Globothalamea, and Tubothalamea. We identified 176 Foraminifera ASVs and found a change in Foraminifera community composition along the beach transects from high tide to low tide level, and a dominance of single-chambered monothalamid Foraminifera. Our results highlight that COI metabarcoding can be a powerful tool for assessing Foraminiferal communities.
    Schlagwort(e): Foraminifera ; Metabarcoding ; Beach ; Community composition ; Intertidal ; Molecular ; biodiversity
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  • 35
    Publikationsdatum: 2024-05-30
    Beschreibung: Shallow-water rhodolith beds are rare in the Mediterranean Sea and generally poorly known. The Punta de la Mona rhodolith bed extends for 16,000 square meters in shallow and oligotrophic waters at the southern coast of Spain, off Almuñecar in the Alborán Sea. We present a detailed analysis of the structure (rhodolith cover and density, rhodolith size and shape, sediment granulometry) and morphospecies composition of the bed along a depth gradient. A stratified sampling was carried out at six depths (9, 12, 15, 18, 21, and 24 m), estimating rhodolith cover and abundance; rhodoliths were collected from one 30 by 30 cm quadrat for each transect, resulting in 18 samples and a total of 656 rhodoliths. The collected rhodoliths were measured and the coralline algal components identified morphoanatomically through a stereomicroscope and SEM. Sediment on the seafloor mainly consisted of pebbles and cobbles; the highest rhodolith cover occurred between 15 and 18 m, and the lowest at the shallowest and deepest transects (9 and 24 m). Mean Rhodolith size was similar throughout the depth range (23–35 mm) with a slight increase at 24 m, although the largest rhodoliths occurred at 21 m. In monospecific rhodoliths, size depended more on the forming species than on depth. We found 25 non-geniculate coralline morphospecies, nearly all rhodolith-forming morphospecies reported in the Mediterranean Sea in recent accounts. The highest morphospecies richness (18–19) and proportional abundance were found at intermediate depths (15–18 m), where rhodolith cover is also highest. Lithophyllum incrustans and Lithophyllum dentatum dominated at shallow depths (9–12 m), whereas Lithothamnion valens was the dominant species at intermediate and greater depths. Overall, the latter species was the most common in the rhodolith bed. The shallow-water rhodolith bed in Punta de la Mona is probably the most diverse in the Mediterranean Sea. This highlights the importance of the conservation of this habitat and, in general, emphasizes the role of the Alborán Sea as a diversity center of coralline algae. The Punta de la Mona example contradicts the common assumption in the geological literature that rhodolith beds are indicative of oligophotic environments with high nutrients levels.
    Schlagwort(e): coralline red algae ; depth-gradient patterns ; rhodolith cover and size ; rhodolith diversity ; Alboran sea
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  • 36
    Publikationsdatum: 2024-05-30
    Beschreibung: In a marine environment that is rapidly changing due to anthropogenic activities and climate change, area-based management tools are often used to mitigate threats and conserve biodiversity. Marine protected areas (MPAs) are amongst the most widespread and recognized marine conservation tools worldwide, however, MPAs alone are inadequate to address the environmental crisis. The promotion of other effective area-based conservation measures (OECMs) under draft Target 3 of the Post-2020 Global Biodiversity Framework, i.e., conserving 30% of marine areas by 2030, holds promise to acknowledge sites and practices occurring beyond MPAs that contribute to conservation. Here, we evaluate the potential recognition of OECMs into Indonesia's national policy framework on marine resource management and provide the first-ever overview of distribution and types of potential marine OECMs in Indonesia, including a review of the existing evidence on conservation effectiveness. We identified 〉 390 potential marine OECMs, led by government, customary and local communities, or the private sector, towards diverse management objectives, including habitat protection, traditional/customary management, fisheries, tourism, or other purposes. While some evidence exists regarding the conservation effectiveness of these practices, the long-term impacts on biodiversity of all potential marine OECMs in Indonesia are unknown. Many OECM elements have been included in several national policies, yet there are no established mechanisms to identify, recognize and report sites as OECMs in Indonesia. We propose four transformational strategies for future OECM recognition in Indonesia, namely: (i) safeguard customary and traditional communities, (ii) leverage cross-sector and cross-scale collaboration, (iii) focus on delivering outcomes, and (iv) streamline legal frameworks. Our study shows that OECMs have the potential to play a significant role in underpinning marine area-based conservation in Indonesia, including supporting the Government of Indonesia in reaching national and international conservation targets and goals.
    Schlagwort(e): Area-based management ; Biodiversity conservation ; Customary management ; Fisheries ; Co-management ; Sustainable marine management
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  • 37
    facet.materialart.
    Unbekannt
    In:  Methods in Ecology and Evolution vol. 14 no. 2, pp. 596-613
    Publikationsdatum: 2024-05-30
    Beschreibung: Coral reefs are the most biodiverse marine ecosystems, and host a wide range of taxonomic diversity in a complex spatial community structure. Existing coral reef survey methods struggle to accurately capture the taxonomic detail within the complex spatial structure of benthic communities. We propose a workflow to leverage underwater hyperspectral image transects and two machine learning algorithms to produce dense habitat maps of 1150 m2 of reefs across the Curaçao coastline. Our multi-method workflow labelled all 500+ million pixels with one of 43 classes at taxonomic family, genus or species level for corals, algae, sponges, or to substrate labels such as sediment, turf algae and cyanobacterial mats. With low annotation effort (only 2% of pixels) and no external data, our workflow enables accurate (Fbeta of 87%) survey-scale mapping, with unprecedented thematic detail and with fine spatial resolution (2.5 cm/pixel). Our assessments of the composition and configuration of the benthic communities of 23 image transects showed high consistency. Digitizing the reef habitat and community structure enables validation and novel analysis of pattern and scale in coral reef ecology. Our dense habitat maps reveal the inadequacies of point sampling methods to accurately describe reef benthic communities.
    Schlagwort(e): coral reefs ; habitat mapping ; hyperspectral imaging ; machine learning ; survey scale mapping ; thematic detail
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  • 38
    Publikationsdatum: 2024-05-30
    Beschreibung: Traditional morphological methods for species identification are highly time consuming, especially for small organisms, such as Foraminifera, a group of shell-building microbial eukaryotes. To analyze large amounts of samples more efficiently, species identification methods have extended to molecular tools in the last few decades. Although a wide range of phyla have good markers available, for Foraminifera only one hypervariable marker from the ribosomal region (18S) is widely used. Recently a new mitochondrial marker cytochrome oxidase subunit 1 (COI) has been sequenced. Here we investigate whether this marker has a higher potential for species identification compared to the ribosomal marker. We explore the genetic variability of both the 18S and COI markers in 22 benthic foraminiferal morphospecies (orders Miliolida and Rotaliida). Using single-cell DNA, the genetic variability within specimens (intra) and between specimens (inter) of each species was assessed using next-generation sequencing. Amplification success rate was twice as high for COI (151/200 specimens) than for 18S (73/200 specimens). The COI marker showed greatly decreased intra- and inter-specimen variability compared to 18S in six out of seven selected species. The 18S phylogenetic reconstruction fails to adequately cluster multiple species together in contrast to COI. Additionally, the COI marker helped recognize misclassified specimens difficult to morphologically identify to the species level. Integrative taxonomy, combining morphological and molecular characteristics, provides a robust picture of the foraminiferal species diversity. Finally, we suggest the use of a set of sequences (two or more) to describe species showing intra-genomic variability additionally to using multiple markers. Our findings highlight the potential of the newly discovered mitochondrial marker for molecular species identification and metabarcoding purposes.
    Schlagwort(e): protist ; high-throughput sequencing ; metabarcoding ; intra-genomic variation ; benthic foraminifera
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  • 39
    Publikationsdatum: 2024-05-30
    Beschreibung: The Maritime Continent (MC) forms the western boundary of the tropical Pacific Ocean, and relatively small changes in this region can impact the climate locally and remotely. In the mid-Piacenzian warm period of the Pliocene (mPWP; 3.264 to 3.025 Ma) atmospheric CO2 concentrations were ∼ 400 ppm, and the subaerial Sunda and Sahul shelves made the land–sea distribution of the MC different to today. Topographic changes and elevated levels of CO2, combined with other forcings, are therefore expected to have driven a substantial climate signal in the MC region at this time. By using the results from the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2), we study the mean climatic features of the MC in the mPWP and changes in Indonesian Throughflow (ITF) with respect to the preindustrial. Results show a warmer and wetter mPWP climate of the MC and lower sea surface salinity in the surrounding ocean compared with the preindustrial. Furthermore, we quantify the volume transfer through the ITF; although the ITF may be expected to be hindered by the subaerial shelves, 10 out of 15 models show an increased volume transport compared with the preindustrial. In order to avoid undue influence from closely related models that are present in the PlioMIP2 ensemble, we introduce a new metric, the multi-cluster mean (MCM), which is based on cluster analysis of the individual models. We study the effect that the choice of MCM versus the more traditional analysis of multi-model mean (MMM) and individual models has on the discrepancy between model results and data. We find that models, which reproduce modern MC climate well, are not always good at simulating the mPWP climate anomaly of the MC. By comparing with individual models, the MMM and MCM reproduce the preindustrial sea surface temperature (SST) of the reanalysis better than most individual models and produce less discrepancy with reconstructed sea surface temperature anomalies (SSTA) than most individual models in the MC. In addition, the clusters reveal spatial signals that are not captured by the MMM, so that the MCM provides us with a new way to explore the results from model ensembles that include similar models.
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  • 40
    facet.materialart.
    Unbekannt
    Frontiers Media SA
    In:  Frontiers for Young Minds vol. 12 no. 1122119 |
    Publikationsdatum: 2024-05-30
    Beschreibung: Lots of creatures live in coral reefs, including some tiny ones you might never have heard of. In this article, we will tell you about the importance of Foraminifera (also called forams), unicellular organisms with shells, that contribute to coral reefs in many ways. Just like corals, some forams living on the seafloor live closely together with microalgae. Some forams also thrive in similar environmental conditions (sunlight, temperature, salt) as corals. For this reason, forams can be used as reef “sensors”, to keep track of the overall health of coral reefs. They can even help to detect poor environmental conditions that might harm coral growth in the future. In this article, we will look at a study of an Indonesian reef ecosystem in which the foram communities living on the seafloor were monitored between 1997 and 2018.
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  • 41
    facet.materialart.
    Unbekannt
    Wiley
    In:  Ecology and Evolution vol. 12 no. e9549 | H2020 European Institute of Innovation and Technology, Grant/Award Number: 813360; Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Grant/ Award Number: 16.161.301
    Publikationsdatum: 2024-05-30
    Beschreibung: Monitoring community composition of Foraminifera (single-celled marine protists) pro-vides valuable insights into environmental conditions in marine ecosystems. Despitethe efficiency of environmental DNA (eDNA) and bulk-sample DNA (bulk-DNA) me-tabarcoding to assess the presence of multiple taxa, this has not been straightforwardfor Foraminifera partially due to the high genetic variability in widely used ribosomalmarkers. Here, we test the correctness in retrieving foraminiferal communities by me-tabarcoding of mock communities, bulk-DNA from coral reef sediment samples, andeDNA from their associated ethanol preservative using the recently sequenced cy-tochrome c oxidase subunit 1 (COI) marker. To assess the detection success, we com-pared our results with large benthic foraminiferal communities previously reportedfrom the same sampling sites. Results from our mock communities demonstrate thatall species were detected in two mock communities and all but one in the remainingfour. Technical replicates were highly similar in number of reads for each assigned ASVin both the mock communities and bulk-DNA samples. Bulk-DNA showed a signifi-cantly higher species richness than their associated eDNA samples, and also detectedadditional species to what was already reported at the specific sites. Our study con-firms that metabarcoding using the foraminiferal COI marker adequately retrieves thediversity and community composition of both the mock communities and the bulk-DNA samples. With its decreased variability compared with the commonly used nu-clear 18 S rRNA, the COI marker renders bulk-DNA metabarcoding a powerful tool toassess foraminiferal community composition under the condition that the referencedatabase is adequate to the target taxa.
    Schlagwort(e): bulk-sample ; DNA ; community composition ; coral reef ; environmental DNA ; foraminifera ; metabarcoding
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  • 42
    facet.materialart.
    Unbekannt
    Australian Museum
    In:  Records of the Australian Museum vol. 75 no. 3, pp. 167-213
    Publikationsdatum: 2024-05-30
    Beschreibung: n the deep ocean, whale falls (deceased whales that sink to the seafloor) act as a boost of productivity in this otherwise generally food-limited setting, nourishing organisms from sharks to microbes during the various stages of their decomposition. Annelid worms are habitual colonizers of whale falls, with new species regularly reported from these settings and their systematics helping to resolve biogeographic patterns among deep-sea organic fall environments. During a 2017 expedition of the Australian research vessel RV Investigator to sample bathyal to abyssal communities off Australia’s east coast, a natural whale fall was opportunistically trawled at ~1000 m depth. In this study, we provide detailed taxonomic descriptions of the annelids associated with this whale-fall community, using both morphological and molecular techniques. From this material we describe nine new species from five families (Dorvilleidae: Ophryotrocha dahlgreni sp. nov. Ophryotrocha hanneloreae sp. nov., Ophryotrocha ravarae sp. nov.; Hesionidae: Vrijenhoekia timoharai sp. nov.; Nereididae: Neanthes adriangloveri sp. nov., Neanthes visicete sp. nov.; Orbiniidae: Orbiniella jamesi sp. nov.), including two belonging to the bone-eating genus Osedax (Siboglinidae: Osedax waadjum sp. nov., Osedax byronbayensis sp. nov.) that are the first to be described from Australian waters. We further provide systematic accounts for 10 taxa within the Ampharetidae, Amphinomidae, Microphthalmidae, Nereididae, Orbiniidae, Phyllodocidae, Protodrilidae, Sphaerodoridae and Phascolosomatidae. Our investigations uncover unique occurrences and for the first time enable the evaluation of biogeographic links between Australian whale falls and others in the western Pacific as well as worldwide.
    Schlagwort(e): polychaete ; chemosynthesis ; organic fall ; bathyal ; Bathymodiolinae ; Pacific Ocean
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  • 43
    Publikationsdatum: 2024-05-30
    Beschreibung: Here we present the experimental design and results from a new mid-Pliocene simulation using the latest version of the UK's physical climate model, HadGEM3-GC31-LL, conducted under the auspices of CMIP6/PMIP4/PlioMIP2. Although two other palaeoclimate simulations have been recently run using this model, they both focused on more recent periods within the Quaternary, and therefore this is the first time this version of the UK model has been run this far back in time. The mid-Pliocene Warm Period, ∼3 Ma, is of particular interest because it represents a time period when the Earth was in equilibrium with CO2 concentrations roughly equivalent to those of today, providing a possible analogue for current and future climate change. The implementation of the Pliocene boundary conditions is firstly described in detail, based on the PRISM4 dataset, including CO2, ozone, orography, ice mask, lakes, vegetation fractions and vegetation functional types. These were incrementally added into the model, to change from a pre-industrial setup to a Pliocene setup. The results of the simulation are then presented, which are firstly compared with the model's pre-industrial simulation, secondly with previous versions of the same model and with available proxy data, and thirdly with all other models included in PlioMIP2. Firstly, the comparison with the pre-industrial simulation suggests that the Pliocene simulation is consistent with current understanding and existing work, showing warmer and wetter conditions, and with the greatest warming occurring over high-latitude and polar regions. The global mean surface air temperature anomaly at the end of the Pliocene simulation is 5.1 ∘C, which is the second highest of all models included in PlioMIP2 and is consistent with the fact that HadGEM3-GC31-LL has one of the highest Effective Climate Sensitivities of all CMIP6 models. Secondly, the comparison with previous generation models and with proxy data suggests a clear increase in global sea surface temperatures as the model has undergone development. Up to a certain level of warming, this results in a better agreement with available proxy data, and the “sweet spot” appears to be the previous CMIP5 generation of the model, HadGEM2-AO. The most recent simulation presented here, however, appears to show poorer agreement with the proxy data compared with HadGEM2 and may be overly sensitive to the Pliocene boundary conditions, resulting in a climate that is too warm. Thirdly, the comparison with other models from PlioMIP2 further supports this conclusion, with HadGEM3-GC31-LL being one of the warmest and wettest models in all of PlioMIP2, and if all the models are ordered according to agreement with proxy data, HadGEM3-GC31-LL ranks approximately halfway among them. A caveat to these results is the relatively short run length of the simulation, meaning the model is not in full equilibrium. Given the computational cost of the model it was not possible to run it for a longer period; a Gregory plot analysis indicates that had it been allowed to come to full equilibrium, the final global mean surface temperature could have been approximately 1.5 ∘C higher.
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  • 44
    Publikationsdatum: 2024-05-30
    Beschreibung: Borys Malkin (1917-2009) is arguably one of the most important yet least known twentieth-cen-tury collectors of Indigenous material culture from South America, with especially numerous collecting expeditions to the Amazon region. In fact, his contact with museums worldwide and the systematic way in which he collected and sold his materials can be characterized as a form of wholesale collecting that rested upon the creation of chains of supply and demand typical of a market economy. In this article, we explore the ways in which Malkin engaged with Indigenous peoples, intermediaries, and museums in South America, North America and in Europe in order to create this network of “producers” or “suppliers”, on the one hand, and potential buyers on the other. We do so by presenting information about the scope and breadth of his Indigenous collections, and then investigating his modus operandi. We conclude that the successful spreading of his collections in various museums and the constant pres-ence in exhibitions of objects from collections formed by Malkin shaped, in a significant way, the face of Lowland South America in ethno-graphic museums of the Global North.
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  • 45
    Publikationsdatum: 2024-05-30
    Beschreibung: Ecological regime shifts in the marine realm have been recorded from a variety of systems and locations around the world. Coral reefs have been especially affected, with their benthic habitat changing from a dominance of stony corals to a dominance of other organisms such as fleshy algae. To detect changes in the benthic habitat of coral reefs, simple tools applicable on a global scale are necessary for future monitoring programs. Hence, the aim of this research is to explore the hypothesis that shifts in assemblages of large benthic foraminifera (LBF) can detect early signs of degradation in the reef benthic habitat. To do so, data on living assemblages of LBF collected between 1997 and 2018 at 12 islands in the Spermonde Archipelago (South Sulawesi, Indonesia) were analyzed. Foraminiferal specimens were morphologically identified to the species level and statistical analyses performed to assess changes in their assemblage composition. A clear temporal shift was observed. Typical foraminiferal assemblages in a coral-dominated (e.g., Amphistegina lobifera, Calcarina spengleri, Heterostegina depressa) and fleshy algaedominated (e.g., Neorotalia gaimardi, C. mayori) reef habitats were identified and significantly linked to the substrate type. Other species (e.g., Elphidium spp., Peneroplis planatus and Sphaerogypsina globulus) seem to reflect a spatial and temporal gradient of anthropogenic pollution from local inhabited islands and ongoing urban development on the mainland. Hence communities of LBF consistently follow gradual shifts in environmental conditions. Additionally to foraminiferal assemblages being an indicator for actual reef condition, closely monitoring LBF may provide early information on reef degradation, in time to take action against identified stressors (e.g., eutrophication or intensive fishing) at local and regional scales. The circumtropical distribution of LBF is such that they can be included worldwide in reef monitoring programs, conditional to calibration to the regional species pool.
    Schlagwort(e): Temporal dynamics ; Bioindicator ; Early detection ; Coral reef ; Spermonde Archipelago ; Indonesia
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  • 46
    Publikationsdatum: 2024-05-30
    Beschreibung: Despite increasing recognition of the need for more diverse and equitable representation in the sciences, it is unclear whether measurable progress has been made. Here, we examine trends in authorship in coral reef science from 1,677 articles published over the past 16 years (2003–2018) and find that while representation of authors that are women (from 18 to 33%) and from non-OECD nations (from 4 to 13%) have increased over time, progress is slow in achieving more equitable representation. For example, at the current rate, it would take over two decades for female representation to reach 50%. Given that there are more coral reef non-OECD countries, at the current rate, truly equitable representation of non-OECD countries would take even longer. OECD nations also continue to dominate authorship contributions in coral reef science (89%), in research conducted in both OECD (63%) and non-OECD nations (68%). We identify systemic issues that remain prevalent in coral reef science (i.e., parachute science, gender bias) that likely contribute to observed trends. We provide recommendations to address systemic biases in research to foster a more inclusive global science community. Adoption of these recommendations will lead to more creative, innovative, and impactful scientific approaches urgently needed for coral reefs and contribute to environmental justice efforts.
    Schlagwort(e): coral reef science ; gender ; equity ; inclusion ; representation ; diversity
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  • 47
    Publikationsdatum: 2024-05-30
    Beschreibung: Laboratory experiments suggest that the evolution of in-plane shear rupture along an interface separating two elastic blocks typically shows a transition from slow to fast slip. In contrast to the commonly used continuum mechanics-based approaches, here we study the shear rupture process along a weak interface using the discontinuous deformation analysis (DDA) method. We incorporate a slip-weakening constitutive friction law to simulate the initiation and propagation of shear rupture under external conditions of a constant normal load and a steadily increased shear load. As the shear load increases, our modeling results reveal a sharp transition from episodic expansion and arrest to unstable runaway rupture, consistent with previous experimental results. In the stage of dynamic runaway, rupture velocity is limited by the Rayleigh wave velocity. We further investigate the effects of external loading conditions including load point velocity and normal stress on rupture behavior. We find that the dynamic rupture velocity increases with load point velocity and normal stress, also consistent with previous studies. Our results indicate that the DDA method can well capture some of the general characteristics of shear rupture process and, hence, can be applied to study other aspects of dynamic shear ruptures.
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  • 48
    Publikationsdatum: 2024-05-30
    Beschreibung: Typical resistant REE phosphates xenotime and monazite are important REE carriers in various types of rocks but the supergene mobility of REE in these minerals remains controversial. In this study, we hypothesize that microbes drive the natural weathering of these resistant REE phosphates. We conducted room-temperature bio-weathering experiments of xenotime concentrate with a common soil bacterium (Bacillus thuringiensis, Bt) isolated from a regolith-hosted REE deposit. Our results showed that Bt was able to promote the dissolution of xenotime and monazite in the concentrate, and the release of REE was enhanced by up to two orders of magnitude. In the bio-weathering medium buffered at pH = 6, the apparent release rates of total REE were in the range of 10−13–10−12 mol·m−2·s−1, with Y releasing at the fastest rates of ∼10−13 mol·m−2·s−1. Furthermore, the estimated dissolution rate of monazite (∼10−9 g·m−2·s−1) was one order of magnitude higher than that of xenotime (∼10−10 g·m−2·s−1) due to a more refractory nature of xenotime determined by its chemical and mineralogical characteristics. On account of the extremely low solubility of REE phosphates, portions of the released REE could be re-precipitated as meta-stable phosphates during mineral dissolution, resulting in the underestimation of the release of REE from primary minerals. Bt could produce various organic acids and acidify the media, promoting the dissolution of resistant phosphates through proton- and ligand-promoted mechanisms. The results of our study suggest that microbes have a high potential to facilitate REE liberation from resistant xenotime and monazite, posing new insight into the biogeochemical cycling of REE on Earth's surface.
    Materialart: info:eu-repo/semantics/article
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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  • 49
    facet.materialart.
    Unbekannt
    In:  Protokoll über das 30. Schmucker-Weidelt-Kolloquium für Elektromagnetische Tiefenforschung: virtuell, 25. September - 29. September 2023
    Publikationsdatum: 2024-05-30
    Sprache: Englisch
    Materialart: info:eu-repo/semantics/conferenceObject
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 50
    facet.materialart.
    Unbekannt
    In:  Protokoll über das 30. Schmucker-Weidelt-Kolloquium für Elektromagnetische Tiefenforschung: virtuell, 25. September - 29. September 2023
    Publikationsdatum: 2024-05-30
    Sprache: Englisch
    Materialart: info:eu-repo/semantics/conferenceObject
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
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