The Centre for Coastal Biogeochemistry (www.scu.edu.au/coastal-biogeochemistry) at Southern Cross University (Lismore, Australia) is offering a PhD scholarship on Seagrass denitrification.
Seagrass habitats are “hotspots” of biogeochemical cycling due to large amounts of organic matter produced by high rates of in situ primary productivity and associated respiration, and because they trap large amounts of externally generated organic matter (e.g. phyto-detritus). In sediments where the overlying water is well-oxygenated with low nitrate, typical of seagrass habitats, the supply of labile carbon is the most important controlling factor on denitrification. Despite a supply of organic matter, earlier measurements in temperate seagrass communities found low rates of denitrification. The low rates of denitrification were thought to be due to coupled nitrification-denitrification in the rhizosphere of temperate seagrass communities being suppressed due to competition for N resources between nitrifying bacteria and seagrass and benthic microalgae. However, we recently measured much higher rates of denitrification in (sub)tropical seagrass communities than have previously been reported for temperate seagrass communities (Eyre et al., 2011 Biogeochemistry 102, 111-133; Eyre et al., 2013. Global Biogeochemical Cycles 27, 1-13; Eyre et al., 2016. L&O 61, 1144-1156).
This study is designed to test the hypothesis that previous differences in seagrass denitrification rates are due to either (1) different rates of biogeochemical processes, which may, in part be driven by species differences and/ or (2) different methodologies used to measure rates of denitrification. As such, this work will use three different denitrification techniques (N2:Ar, isotope pairing, NO3 microsensor) and N-fixation, N2O, anammox and DNRA measurements in different seagrass communities in Australia and Denmark. This project involves collaboration with Prof. Ronnie Glud at the University of Southern Denmark and there may be opportunity to undertake field work in Denmark.
Submitting an Application
Applicants will need to have a 1st Class Honours or Master degree in English in a related field such as biogeochemistry, environmental chemistry, or closely related. Previous research experience with benthic process measurements (cores and/or benthic chambers), seagrasses and/or aquatic nitrogen cycling will be viewed favourably. The projects will involve extended periods in the field, including in small boats, and previous small boat experience will be advantageous. Interested applicants should send their CV, and a short letter highlighting their research background to:
Prof. Bradley Eyre – Bradley.firstname.lastname@example.org
Only short-listed applicants will be notified. Closing date October 15 2016, although may extend longer if the position is not filled. Starting date, by January 30 2017.
The scholarship currently valued at $25,800 is open to both Australian and international applicants and is tax free. Tuition fees will be waived. The project will be undertaken in the Centre for Coastal Biogeochemistry (www.scu.edu.au/coastal-biogeochemistry) at Southern Cross University which received the highest rank of 5.0, well above world average, in geochemistry in the most recent assessment of research excellence by the Australian government.