[ES_JOBS_NET] PhD scholarships in Australia Centre for Coastal Biogeochemistry

[Erika Marín-Spiotta]

---------- Forwarded message ----------
From: Joanne Oakes <Joanne.Oakes at scu.edu.au>
Date: Tue, Jul 26, 2016 at 11:33 PM


I would like to draw your attention to the following PhD scholarship
opportunities based at Southern Cross University, Australia. The positions
are open to national and international applicants. Closing date is 28th
August 2016.

__________________________________________________________________________________________________________



The Centre for Coastal Biogeochemistry (
www.scu.edu.au/coastal-biogeochemistry) at Southern Cross University
(Lismore, Australia) is offering two PhD scholarships.



*Project 1: 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).

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) 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.



*Project 2: Whole-system additions of stable isotope tracers to investigate
carbon and nitrogen cycling in coastal ecosystems*

Anthropogenic activities are changing the quality and quantity of carbon
(C) and nitrogen (N) inputs to coastal systems. Coastal ecosystems, located
at the land-sea interface, are in a prime position to intercept these
inputs. The transformation of C and N within coastal ecosystems therefore
determines the quality and quantity of inputs from the land to the sea and
affects the ultimate impact of changing land-uses and anthropogenic inputs
on oceanic and global C and N budgets. Stable isotopes, particularly when
used as deliberate tracers, are widely recognised as a powerful technique
for tracing the flows of C and N in the environment (e.g. Oakes et al.
2012. Limnology and Oceanography 5*7*, 1846-1856; Eyre et al. 2016.
Limnology and Oceanography in press). Deliberate tracer studies of whole
ecosystems are relatively rare, but can provide important information on
the role of whole ecosystems in carbon and nitrogen processing (e.g. Erler
et al., 2010. Limnology and Oceanography 55, 1172-1187).

In this project we propose to use rare stable isotopes of C and N in
whole-system labelling studies to unravel the role of coastal ecosystems in
the uptake and transformation of C and N. The study will include the use of
stable isotope tracers, biogeochemical process measurements, and the
measurement of stable isotopes within compartments including dissolved
compounds, particulate matter, animals, gases, sediment, and biomarkers to
create budgets for C and N transformation and fate. There is potential to
work within habitats including mangrove forests, salt marshes, seagrass
beds, and coral reefs.



*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. For project 1 previous research experience
with benthic process measurements (cores and/or benthic chambers),
seagrasses and/or aquatic nitrogen cycling will be viewed favourably. For
project 2 previous research experience with stable isotopes and vegetated
aquatic systems will be viewed favourably. Both 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:



Project 1. Prof. Bradley Eyre – Bradley.eyre at scu.edu.au

Project 2. Dr. Joanne Oakes - Joanne.Oakes at scu.edu.au



Only short-listed applicants will be notified. Closing date August 28 2016,
although may extend longer if the position is not filled. Starting date, by
January 30 2017.



The scholarships, currently valued at $25,800, are open to both Australian
and international applicants and are tax free. Tuition fees will be waived. All
the projects 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.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/es_jobs_net/attachments/20160727/c22309b9/attachment.html