72 research outputs found
Assessing the ecological vulnerability of the shallow steppe Lake Neusiedl (Austria-Hungary) to climate-driven hydrological changes using a palaeolimnological approach
9openInternationalBothLake Neusiedl, the largest steppe lake in Europe, is particularly sensitive to climate variations due to its extreme shallowness (zmax = 1.8 m) and low ratio of catchment to lake area (3.5 : 1). Changes in water budget, salinity and turbidity have key implications for the lake’s ecology and management. Here, we present a multi-proxy palaeolimnological reconstruction of the evolution of Lake Neusiedl since the end of its last complete desiccation (1865–1868), based on an undisturbed radiometrically dated core taken from the open water portion of the lake. Geochemical and biological (algal) proxies outline the succession of three major ecological stages since 1873 ± 16 yrs, with the first major changes appearing already in the 1930s as driven by climate related hydrological variability. Subfossil diatoms proved to be reliable for tracking long-term changes in the trophic conditions of Lake Neusiedl while diatom-inferred lake conductivity revealed to be unreliable due to a combination of lake environmental settings and the absence of a site-specific training set. Nonetheless, multivariate statistical analyses and comparisons with limnological data confirm a great potential of subfossil diatoms for revealing past ecological changes and tipping points of shallow lakes, as long as studies rely on a multi-proxy approach. In agreement with limnological surveys, the sediment record corroborates the high vulnerability of Lake Neusiedl, both in present and past times, towards climate-driven changes in water level and salinity, and allows the prediction, by analogy with the past, of future ecological changes in a context of global warming and increasing nutrient inputs from non-point sources.openTolotti, M.; Guella, G.; Herzig, A.; Rodeghiero, M.; Rose, N.L.; Soja, G.; Zechmeister, T.; Yang, H.; Teubner, K.Tolotti, M.; Guella, G.; Herzig, A.; Rodeghiero, M.; Rose, N.L.; Soja, G.; Zechmeister, T.; Yang, H.; Teubner, K
Thermal characteristics of springs fed by mountain permafrost in Val di Sole (Eastern Italian Alps)
In alpine areas, spring-water temperature is affected by the presence of permafrost and by changes in the periglacial domain caused by the current atmospheric warming. Our interest in spring-water temperature is related to the possibility of investigating the spatial distribution of alpine permafrost and its changes. In particular, spring-water temperature might be helpful as indicator of permafrost occurrence in areas where it is discontinuous or sporadic, and in general where its distribution is poorly known. The spring-water temperature in late summer is a useful evidence of permafrost, and various authors employed such method as auxiliary permafrost evidence, or as a stand-alone method that can be used for mapping permafrost distribution at the catchment scale. However, little is known on the spatial and temporal variability of water temperature at springs with different permafrost contribution and characteristics. Here we present an analysis of the spatial and temporal variability of spring-water temperature in a 795 km2 catchment located in the Eastern Italian Alps, aimed at investigating the spatial distribution of permafrost and its effect on spring-water temperature. From 2018 to 2021, we measured the late-summer spring-water temperature at 220 springs, 133 of which are located downslope of rock glaciers, 81 downslope of other deposits, and 8 in bedrock. In addition, we installed dataloggers for continuous temperature measurements at 31 springs. Results show that the cold springs are mainly associated with intact rock glaciers but also with rock glaciers classified as relict, especially if they have blocky and sparsely vegetated surface. Accordingly, the latter should be reclassified as pseudo-relict, i.e. they appear to be visually relict but host patchy permafrost, as confirmed by geophysics carried out at selected case studies. These results have important implications for the study and modelling of the hydrological, hydrochemical and ecological response of periglacial environments under ongoing climate change
Plasmopara viticola infection affects mineral elements allocation and distribution in Vitis vinifera leaves
Plasmopara viticola is one of the most important pathogens infecting Vitis vinifera plants. The interactions among P. viticola and both susceptible and resistant grapevine plants have been extensively characterised, at transcriptomic, proteomic and metabolomic levels. However, the involvement of plants ionome in the response against the pathogen has been completely neglected so far. Therefore, this study was aimed at investigating the possible role of leaf ionomic modulation during compatible and incompatible interactions between P. viticola and grapevine plants. In susceptible cultivars, a dramatic redistribution of mineral elements has been observed, thus uncovering a possible role for mineral nutrients in the response against pathogens. On the contrary, the resistant cultivars did not present substantial rearrangement of mineral elements at leaf level, except for manganese (Mn) and iron (Fe). This might demonstrate that, resistant cultivars, albeit expressing the resistance gene, still exploit a pathogen response mechanism based on the local increase in the concentration of microelements, which are involved in the synthesis of secondary metabolites and reactive oxygen species. Moreover, these data also highlight the link between the mineral nutrition and plants\u2019 response to pathogens, further stressing that appropriate fertilization strategies can be fundamental for the expression of response mechanisms against pathogens
Factors controlling the water quality of rock glacier springs in European and American mountain ranges
Rock glaciers (RGs) provide significant water resources in mountain areas under climate change. Recent research has highlighted high concentrations of solutes including trace elements in RG-fed waters, with negative implications on water quality. Yet, sparse studies from a few locations hinder conclusions about the main drivers of solute export from RGs. Here, in an unprecedented effort, we collected published and unpublished data on rock glacier hydrochemistry around the globe. We considered 201 RG springs from mountain ranges across Europe, North and South America, using a combination of machine learning, multivariate and univariate analyses, and geochemical modeling. We found that 35 % of springs issuing from intact RGs (containing internal ice) have water quality below drinking water standards, compared to 5 % of springs connected to relict RGs (without internal ice). The interaction of ice and bedrock lithology is responsible for solute concentrations in RG springs. Indeed, we found higher concentrations of sulfate and trace elements in springs sourcing from intact RGs compared to water originating from relict RGs, mostly in specific lithological settings. Enhanced sulfide oxidation in intact RGs is responsible for the elevated trace element concentrations. Challenges for water management may arise in mountain catchments rich in intact RGs, and where the predisposing geology would make these areas geochemical RG hotspots. Our work represents a first comprehensive attempt to identify the main drivers of solute concentrations in RG water
Inelastic Black Hole Scattering from Charged Scalar Amplitudes
We explain how the lowest-order classical gravitational radiation produced
during the inelastic scattering of two Schwarzschild black holes in General
Relativity can be obtained from a tree scattering amplitude in gauge theory
coupled to scalar fields. The gauge calculation is related to gravity through
the double copy. We remove unwanted scalar forces which can occur in the double
copy by introducing a massless scalar in the gauge theory, which is treated as
a ghost in the link to gravity. We hope these methods are a step towards a
direct application of the double copy at higher orders in classical
perturbation theory, with the potential to greatly streamline gravity
calculations for phenomenological applications.Comment: 28 pages, 6 figure
The Kerr-Schild double copy in curved spacetime
We thank Tim Adamo, Ricardo Monteiro and Donal O’Connell for discussions and / or
comments on the manuscript. CDW and NBA are supported by the U.K. Science and
Technology Facilities Council (STFC). AL is funded by a Conacyt studentship, and thanks
Queen Mary University of London for hospitalit
Global Spatial Risk Assessment of Sharks Under the Footprint of Fisheries
Effective ocean management and conservation of highly migratory species depends on resolving overlap between animal movements and distributions and fishing effort. Yet, this information is lacking at a global scale. Here we show, using a big-data approach combining satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries. Space use hotspots of commercially valuable sharks and of internationally protected species had the highest overlap with longlines (up to 76% and 64%, respectively) and were also associated with significant increases in fishing effort. We conclude that pelagic sharks have limited spatial refuge from current levels of high-seas fishing effort. Results demonstrate an urgent need for conservation and management measures at high-seas shark hotspots and highlight the potential of simultaneous satellite surveillance of megafauna and fishers as a tool for near-real time, dynamic management
Slaughter weight rather than sex affects carcass cuts and tissue composition of Bisaro pigs
Carcass cuts and tissue composition were assessed in Bisaro pigs (n=64) from two sexes (31 gilts and 33 entire
males) reared until three target slaughter body-weights (BW) means: 17 kg, 32 kg, and 79 kg. Dressing percentage
and backfat thickness increased whereas carcass shrinkage decreased with increasing BW. Slaughter
weight affected most of the carcass cut proportions, except shoulder and thoracic regions. Bone proportion
decreased linearly with increasing slaughter BW, while intermuscular and subcutaneous adipose tissue depots
increased concomitantly. Slaughter weight increased the subcutaneous adipose tissue proportion but this impaired
intramuscular and intermuscular adipose tissues in the loin primal. The sex of the pigs minimally affected
the carcass composition, as only the belly weight and the subcutaneous adipose tissue proportions were greater
in gilts than in entire males. Light pigs regardless of sex are recommended to balance the trade-offs between
carcass cuts and their non-edible compositional outcomes.Work included in the Portuguese PRODER research Project
BISOPORC – Pork extensive production of Bísara breed, in two alternative
systems: fattening on concentrate vs chesnut, Project PRODER SI
I&DT Medida 4.1 “Cooperação para a Inovação”. The authors are
grateful to Laboratory of Carcass and Meat Quality of Agriculture
School of Polytechnic Institute of Bragança ‘Cantinho do Alfredo’. The
authors are members of the MARCARNE network, funded by CYTED
(ref. 116RT0503).info:eu-repo/semantics/publishedVersio
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