Featured
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Letter |
Seasonality of temperate forest photosynthesis and daytime respiration
Climate models require an understanding of ecosystem-scale respiration and photosynthesis, yet there is no way of measuring these two fluxes directly; here, new instrumentation is used to determine these fluxes in a temperate forest, showing, for instance, that respiration is less during the day than at night.
- R. Wehr
- , J. W. Munger
- & S. R. Saleska
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Letter |
Global separation of plant transpiration from groundwater and streamflow
Soil water is usually assumed to be equally available for all purposes, supplying plant transpiration as well as groundwater and streamflow; however, a study of hydrogen and oxygen isotopes from 47 globally distributed sites shows that in fact the water used by plants tends to be isotopically distinct from the water that feeds streamflow.
- Jaivime Evaristo
- , Scott Jasechko
- & Jeffrey J. McDonnell
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Letter |
Methane dynamics regulated by microbial community response to permafrost thaw
The abundance of key microbial lineages can be used to predict atmospherically relevant patterns in methane isotopes and the proportion of carbon metabolized to methane during permafrost thaw, suggesting that microbial ecology may be important in ecosystem-scale responses to global change.
- Carmody K. McCalley
- , Ben J. Woodcroft
- & Scott R. Saleska
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Letter |
Nitrogen losses in anoxic marine sediments driven by Thioploca–anammox bacterial consortia
A novel symbiotic consortium is described between two chemolithotrophic bacteria — anaerobic ammonium-oxidizing (anammox) bacteria and the nitrate-sequestering sulphur-oxidizing Thioploca species — in anoxic sediments of the Soledad basin at the Mexican Pacific margin.
- M. G. Prokopenko
- , M. B. Hirst
- & D. M. Sigman
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Letter |
Terrestrial water fluxes dominated by transpiration
An analysis of the relative effects of transpiration and evaporation, which can be distinguished by how they affect isotope ratios in water, shows that transpiration is by far the largest water flux from Earth’s continents, representing 80 to 90 per cent of terrestrial evapotranspiration and using half of all solar energy absorbed by land surfaces.
- Scott Jasechko
- , Zachary D. Sharp
- & Peter J. Fawcett
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Letter |
Early differentiation and volatile accretion recorded in deep-mantle neon and xenon
Noble gas contents of the Iceland mantle plume show that neither the Moon-forming impact nor billions of years of mantle convection has erased the signature of Earth’s heterogeneous accretion and early differentiation.
- Sujoy Mukhopadhyay
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Letter |
Hafnium isotope evidence for a transition in the dynamics of continental growth 3.2 Gyr ago
Hafnium isotope ratios obtained from zircons in southern West Greenland suggest that Earth’s ancient crustal growth changed around 3.2 Gyr ago to a modern geodynamic regime involving juvenile crust generation by plate tectonic processes.
- T. Næraa
- , A. Scherstén
- & M. J. Whitehouse
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News |
Egyptian kingdoms dated
Radioactive isotopes nail the timeline of Egyptian dynasties.
- Richard Lovett