Understanding the mechanisms, causes and consequences of the climate changes is one of the major challenges of todays environmental research. In this context, a better knowledge of the ecological changes due to the global warming is essential for management of natural resources. In arid environments, lakes are particularly vulnerable. An increase of few degrees may affect lake chemistry and aquatic organism communities that are often at the limit of survival. To cope with temperature variations, organisms have developed various physiological and morphological mechanisms involving the regulation of the lipid constituents from cell membrane and the evolution of resistance- conferring genotypes. Organisms that will not be able to cope with increasing temperature will be replaced by new species. Under extreme conditions, microorganisms like archaea become often dominant members of the community.
By combining the molecular and isotopic analyses of lipids with functional genes or group-specific 16S rRNA genes in lake water particulates and lake surface sediments, we aim to determine the effect of temperature on 1) the lipid constituents of cell membrane of organisms and on 2) DNA-based dominant communities. A PhD study is proposed for each of these topics (for more details see below). Proposed for these studies are lakes located in the Argentinian deserts characterized by precipitation isolines oriented north-to-south and northwards increasing mean annual temperature. This worldwide unique setting allows us to isolate temperature as a main variable, and to select lake areas with similar precipitation rate (ca. 250 mm/year) and vegetation (grass-dominated ecosystems), but increasing mean annual temperature from ~4 °C in the South to ~16 °C in the North.
As the primary interface between the organisms and the environment, the lipids of the cell membrane play a key role in maintaining organisms integrity within a hostile environment, and are thus excellent sensors of environmental stress. These lipids are well preserved in sediments, therefore they have commonly been used to re-construct past ecosystems. We aim to quantify the effects of temperature on the distribution and isotopic composition of lipids in organisms from lakes and their catchments along the temperature gradient. The comparison of the organisms characteristics with those of associated lake sediments will be used to estimate the impact of climate change in arid environments and calibrate paleoproxies using molecular and isotopic composition of lipids in lake sediments. The PhD candidate will be advised by Valérie F. Schwab, Gerd Gleixner (both based at the Max Planck Institute for Biogeochemistry) and Kirsten Küsel (Friedrich Schiller University Jena).
About the school
The International Max Planck Research School for Global Biogeochemical Cycles located in Jena, Germany, offers fellowships to outstanding students interested in research on biogeochemical cycles in the Earth system. The school provides excellent research possibilities for students to obtain a PhD degree in a 3-years graduate program.
The elements key to life such as carbon, oxygen, hydrogen, and nitrogen are continuously exchanged among the land, ocean and atmosphere in what are known as global biogeochemical cycles. Research in the IMPRS-gBGC discovers how these cycles function, how they are interconnected, and how they can change with climate or human activity. In their thesis projects, students deal with various crucial aspects of global biogeochemical cycles and participate in ongoing research comprising field observations, method development, experiments, and modeling. Students will also benefit from a three-month external research visit, specialised courses in e.g. statistics, Earth observation, modelling and analytical techniques, as well as in soft skills and will have ample opportunity to develop their personal career networks. The school is thus an excellent starting platform for a successful career in a field related to global biogeochemical cycles and Earth System Science.
Applications for the program are open to well-motivated and highly-qualified students from all countries. A prerequisite for joining the school is a diploma or master of science degree in geophysical sciences, environmental sciences, biological sciences, physics, chemistry, computer sciences or related fields, including a corresponding thesis. Proficiency in English is required since English is the official language of the program.
As a candidate for this particular PhD project, you should have a degree in natural sciences, preferably with knowledge on arid or lake ecosystems. Experiences in lab work with operation of scientific instrumentation for molecular compound identification or isotopic analyses are an advantage. You are proactive and able to work in a multi-disciplinary project.
How to apply
We accept applications for PhD scholarships until February 03, 2013. Top candidates will be invited to take part in our selection symposium on April 15-16, 2013.
Find out more and apply online: http://www.imprs-gbgc.de
After you have been selected...
The IMPRS office will happily assist you with your transition to Jena.
Successful applicants for this fully funded position are expected to join us in spring-summer 2013. There are no tuition fees. Handicapped persons with comparable qualifications receive preferential status.
Please click on the links below for further information about careers and employment in the aquatic sciences.