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November 9, 2020

Rare, extreme rainfall events dominate nitrous oxide emissions from hyper arid deserts (AtacamaN20)

Rare, extreme rainfall events dominate nitrous oxide emissions from hyper arid deserts

The Atacama Desert is the oldest and driest desert on earth. It is also one of the most hostile environments for microbial life on Earth due to its hyper arid moisture regime, thermal extremes, high concentrations of salt in the soil, and intense UV radiation at the soil surface.  Nevertheless, the Atacama Desert is not totally devoid of life. Short term water inputs caused by fog or rare rainfall events may provide temporary favourable conditions for microorganisms and plants. Recent research has showed that these microbial communities respond rapidly to the addition of available carbon (C) when moisture limitation is removed.

Biological denitrification, which is the major nitrogen (N) loss mechanism in terrestrial ecosystems, occurs via the sequential reduction of NO3, to NO2, NO, N2O and N2, however its functional significance in hyper-arid ecosystem remains largely unknown. However, large instantaneous pulses of nitrogen oxide have been reported from comparable desert soils following rewetting, with recorded fluxes being greater than for other key ecosystems on the planet. The AtacamaN20 project will evaluate what are the key controls of N2O emissions during and after extreme weather events, and following the more continuous but small inputs of water via fog. See https://www.youtube.com/watch?v=Rve8fDZ8DdQ for extreme weather impact in  Atacama region.

You will explore the effects of extreme rainfall on nitrogen cycling in desert environments, focussing on factors controlling N2O production and emission. You will become competent in the use state-of-the-art methods in Bangor University and Rothamsted Research North Wyke to study atmosphere-soil-plant interactions, including portable field and specialist laboratory greenhouse gas emission measurement equipment, stable and radio-isotopes and analysis of the nitrifier and denitrifier communities. Working with international peer colleagues in the Atacama desert you will explore how long term hyper aridity impacts on the landscape and why extreme rainfall events do have such deep impacts on its ecosystem functioning and the resulting N emissions to air.

Eligibility

Applicant should hold a 2:1 degree or above in a subject related to this PhD project including: Biology, Environmental Sciences, Microbiology, Agriculture, Soil Science, Biotechnology, Meteorology.

Enquiries

For further information please contact Dr. Laura Cardenas (laura.cardenas@rothamsted.ac.uk)  or Prof. Roland Bol (r.bol@bangor.ac.uk.