Publications related to Isotopic analysis of cyanobacterial nitrogen fixation associated with subarctic lichen and bryophyte species

Diagenetic isotope exchange in biocalcites for paleoclimate reconstruction

The oxygen isotope compositions of fossil biocalcites, such as foraminifera, bivalves, brachiopods, and belemnites have allowed for reconstructions of sea surface and deep ocean temperatures throughout the Phanerozoic and constitute the most important reco ...

EPFL2024

Invasive palms have more efficient and prolonged CO2 assimilation compared to native sub-Mediterranean vegetation

Marco Conedera, Thibaut Michel Georges Juillard, Charlotte Grossiord, Christoph Bachofen, Janisse Deluigi

In sub-Mediterranean ecosystems, shade-tolerant broadleaf evergreens, especially the invasive Trachycarpus fortunei, are spreading uncontrollably in the forest understorey, impeding the regeneration of the native deciduous woody vegetation. Most invasive s ...

Elsevier2024

The isotopic signature of U(V) during bacterial reduction

Marinella Mazzanti, Rizlan Bernier-Latmani, Radmila Faizova, Margaux Camille Andréa Molinas, Ashley Richards Brown

The two-step electron transfer during bacterial reduction of UVI to UIV is typically accompanied by mass-independent fractionation of the 238U and 235U isotopes, whereby the heavy isotope accumulates in the reduced product. However, the role of the UV inte ...

2024

From roots to canopy: Unraveling the influence of species diversity on tree water relations under warmer and drier climates

Eugénie Isabelle Mas

The worsening of drought events with rising air temperature alters tree water relations causing severe hydraulic impairments and widespread forest mortality. Mixing tree species with contrasting hydraulic traits could reduce forest vulnerability to extreme ...

EPFL2024

Technical note: Two-component electrical-conductivity-based hydrograph separation employing an exponential mixing model (EXPECT) provides reliable high-temporal-resolution young water fraction estimates in three small Swiss catchments

Davide Canone, Jana Freiin von Freyberg

The young water fraction represents the portion of water molecules in a stream that have entered the catchment relatively recently, typically within 2-3 months. It can be reliably estimated in spatially heterogeneous and nonstationary catchments from the a ...

Copernicus Gesellschaft Mbh2024

Organic matters, but inorganic matters too: column examination of elevated mercury sorption on low organic matter aquifer material using concentrations and stable isotope ratios

Lorenz Schwab

Sorption of mercury (Hg) in soils is suggested to be predominantly associated with organic matter (OM). However, there is a growing collection of research that suggests that clay minerals and oxides are also important solid phases for the sorption of solu ...

2024

Multi-year time series of daily solute and isotope measurements from three Swiss pre-Alpine catchments

Jana Freiin von Freyberg

Time series analyses of solute concentrations in streamwater and precipitation are powerful tools for unraveling the interplay of hydrological and biogeochemical processes at the catchment scale. While such datasets are available for many sites around the ...

Nature Portfolio2024

Reproductive isolation arises during laboratory adaptation to a novel hot environment

Ana Marija Jaksic

Background: Reproductive isolation can result from adaptive processes (e.g., ecological speciation and mutation-order speciation) or stochastic processes such as "system drift" model. Ecological speciation predicts barriers to gene flow between populations ...

BMC2024

Metabolic Performance and Fate of Electrons during Nitrate-Reducing Fe(II) Oxidation by the Autotrophic Enrichment Culture KS Grown at Different Initial Fe/N Ratios

Natalia Jakus

Autotrophic nitrate-reducing Fe(II)-oxidizing (NRFeOx) microorganisms fix CO2 and oxidize Fe(II) coupled to denitrification, influencing carbon, iron, and nitrogen cycles in pH-neutral, anoxic environments. However, the distribution of electrons from Fe(II ...

AMER SOC MICROBIOLOGY2023

Coupled carbon and nitrogen cycling regulates the cnidarian–algal symbiosis

Anders Meibom, Stéphane Laurent Escrig, Nils Rädecker

Efficient nutrient recycling underpins the ecological success of cnidarian-algal symbioses in oligotrophic waters. In these symbioses, nitrogen limitation restricts the growth of algal endosymbionts in hospite and stimulates their release of photosynthates ...

Nature Research2023

Photobiology and metabolic interactions in the symbiotic jellyfish Cassiopea

Niclas Heidelberg Lyndby

The symbiont-bearing jellyfish Cassiopea live a benthic lifestyle, positioning themselves upside-down on sediments in shallow waters to allow their endosymbiotic algae to photosynthesize in the sunlight. Over the last decades Cassiopea has become increasin ...

EPFL2023

Excess labile carbon promotes diazotroph abundance in heat-stressed octocorals

Claudia Isabella Pogoreutz

Nitrogen limitation is the foundation of stable coral-algal symbioses. Diazotrophs, prokaryotes capable of fixing N-2 into ammonia, support the productivity of corals in oligotrophic waters, but could contribute to the destabilization of holobiont function ...

ROYAL SOC2023

Metabolism of the symbiotic jellyfish Cassiopea in a changing environment

Gaëlle Delphine Toullec

Ocean warming and other anthropogenic impacts have led to a global decline in many photosymbiotic cnidarians, most notably reef-building corals. But some species of the symbiotic and (sub-)tropical upside-down jellyfish Cassiopea are increasingly reported ...

EPFL2023

Symbiotic nutrient cycling enables the long-term survival of Aiptasia in the absence of heterotrophic food sources

Anders Meibom, Nils Rädecker

Phototrophic Cnidaria are mixotrophic organisms that can complement their het- erotrophic diet with nutrients assimilated by their algal endosymbionts. Metabolic mod- els suggest that the translocation of photosynthates and their derivatives from the algae ...

2023

Isotope Ratio - Discharge Relationships of Solutes Derived From Weathering Reactions

Paolo Benettin

To date, the vast majority of studies seeking to link discharge to solute concentrations have been based on representations of fluid age distributions in watersheds that are time-invariant. As increasingly detailed spatial and temporal datasets become avai ...

Amer Journal Science2023

Assessing sublimation during snow transport and sublimation effects on the isotopic composition of water vapor

Armin Sigmund

Sublimation influences the water storage in snow covers and glaciers, which is important for water use and projections of the sea level rise. Yet, it is challenging to quantify sublimation for large areas or in conditions of snow transport. In-situ measure ...

EPFL2023

Chronic warming and dry soils limit carbon uptake and growth despite a longer growing season in beech and oak

Yann Vitasse, Charlotte Grossiord, Margaux Clara Lou Didion-Gency

Progressively warmer and drier climatic conditions impact tree phenology and carbon cycling with large consequences for forest carbon balance. However, it remains unclear how individual impacts of warming and drier soils differ from their combined effects ...

Oxford Univ Press Inc2023

Rapid grain boundary diffusion in foraminifera tests biases paleotemperature records

Lukas Baumgartner, Anders Meibom, Jaroslaw Hubert Stolarski, Arthur Adams, Deyanira Graciela Cisneros Lazaro, Jinming Guo

The paleoseawater temperature record from the oxygen isotope compositions of fossil foraminifera tests may be biased by up to about 1 degrees C due to grain-boundary diffusion alone, according to isotope exchange experiments on foraminifera tests. The oxyg ...

2023

Mercury Isotope Fractionation during Dark Abiotic Reduction of Hg(II) by Dissolved, Surface-Bound, and Structural Fe(II)

Lorenz Schwab

Stable mercury (Hg) isotope ratios are an emerging tracer for biogeochemical transformations in environmental systems, but their application requires knowledge of isotopic enrichment factors for individual processes. We investigated Hg isotope fractionatio ...

Amer Chemical Soc2023

A Case Study on Drivers of the Isotopic Composition of Water Vapor at the Coast of East Antarctica

Michael Lehning, Armin Sigmund, Riqo Chaar

Stable water isotopes (SWIs) contain valuable information on the past climate and phase changes in the hydrologic cycle. Recently, vapor measurements in the polar regions have provided new insights into the effects of snow-related and atmospheric processes ...

AMER GEOPHYSICAL UNION2023