Doctoral student in Biology - Hiring in process/Finished, not possible to apply

Work duties

The main duties of doctoral students are to devote themselves to their research studies which includes participating in research projects and third cycle courses. The work duties can also include teaching and other departmental duties, up to 20%.

Supplement with further details about the research project and work duties.

The microbial feedback to warming: using thermal traits to link microbes to biogeochemistry

This project will improve our understanding of the soil C feedback from microorganisms due to climate change induced warming. Microorganisms play a crucial role in the global C cycle. The balance between the microbial release of C to the atmosphere due to respiration and microbial use of C for growth – and subsequent potential sequestration in soil  – will determine if terrestrial systems become sources or sinks for atmospheric CO2. The primary physiological factor that determines how microorganisms partition their C-use into catabolic energy generation or for anabolic growth is the carbon-use efficiency (CUE) . Climatic warming will affect the activity and adaptation of microorganisms, however, the microbial feedback to these changes remains unknown. Moreover, warming also induces a complex set of indirect effects, including changes to plant productivity, drought, and changes in nutrient availabilities, etc. Each of these indirect effects is also likely to influence the CUE of the microbial community. This microbial C-feedback to the atmosphere is probably one of the most critical, yet least known, parts of climate-C cycle modelling; emphasizing the urgency for this research . The main objective of this project is to determine the effects of soil warming on microbial CUE in different biomes and across seasons.

The central objective is to assess the temperature dependences of microbial growth and respiration in several climates – including arctic, temperate and tropical ecosystems – to elucidate the type, magnitude and speed of with which thermal traits respond to change. We will determine if different biomes are differently affected by warming, and the seasonal variation of the trait adaptation, and its persistence over time. This will be addressed by following the specific research objectives below:

1. We will determine how warming affect microbial thermal traits, and how indirect effects of warming (plant input, drought, etc.) modulate these responses.

2. We will evaluate if any changes in temperature relationships will have consequences for the microbial CUE, and how indirect effects interact.

3. We will link responses in microbial taxonomy to changes in thermal traits, to connect structure and function.

The project is curiosity-driven, with a basic science foundation, and open to freely develop based on the interests of the PhD student and supervisor team.

The project will involve state-of-art tracking radio- and stable isotopic tracing methods to estimate carbon and nutrient fluxes in soil, and methods to resolve the growth rates of soil microbes in high temporal resolution. There will also be opportunities to characterise fractions of microbial biomass, necromass, and soil organic matter fractions, with the ambition to track isotopic signals into them. In addition, various methods will be employed to characterise soil characteristics including aggregate water stability, and fractionation methods. These mixed approaches will include the use of a wide array of analytical methods, including GCs, HPLCs, Liquid scintillators, Isotope Ratio Mass Spectrometry, etc.

The project will include field components, but will be laboratory intensive.

Admission requirements

A person meets the general admission requirements for third-cycle courses and study programmes if he or she:

• has been awarded a second-cycle qualification, or

• has satisfied the requirements for courses comprising at least 240 credits of which at least 60 credits were awarded in the second cycle, or

• has acquired substantially equivalent knowledge in some other way in Sweden or abroad.

A person meets the specific admission requirements for third cycle studies in Biology if he or she has passed an independent project (for example a degree project) of at least 30 credits in a relevant subject and have good oral and written proficiency in English.

Additional requirements

Candidates should have an advanced university degree (M.Sc. or equivalent experience / competence) in biology, biogeochemistry, environmental science, or equivalent fields, preferably with a focus on microbial ecology. Proficiency in English is a requirement. Documented experience with research (e.g. master thesis or equivalent), and with laboratory methods relevant to the project are important merits.

In addition to the mandatory requirements, documented experience in the following areas will be considered as strong merits:

• Documented experience with analytical methods to resolve microbial communities, including the use of biomarkers, amplicon sequencing, or similar

• Documented experience with the use of radiotracers or stable isotope tracers

• Documented experience with the use of methods to charactise physical, chemical or biological components of soil or environmental samples.

Assessment criteria

Selection for third-cycle studies is based on the student’s potential to profit from such studies. The assessment of potential is made primarily on the basis of academic results from the first and second cycle. Special attention is paid to the following:

• Knowledge and skills relevant to the thesis project and the subject of study.

• An assessment of ability to work independently and to formulate and tackle research problems.

• Written and oral communication skills

• Other experience relevant to the third-cycle studies, for example professional experience.

Consideration will also be given to strong collaborative skills, drive and independence, and how the applicant, through his or her experience and skills, is deemed to have the abilities necessary for successfully completing the third cycle programe.

Terms of employment

Only those admitted to third cycle studies may be appointed to a doctoral studentship. Third cycle studies consist of full-time studies for 4 years. A doctoral studentship is a fixed-term employment of a maximum of 5 years (including 20% departmental duties). Doctoral studentships are regulated in the Higher Education Ordinance (1993:100), chapter 5, 1–7 §§.

Instructions on how to apply

The application should include a letter that includes the motivation for PhD studies, and a description of previous education and research interests (max 2 pages). It should further include a curriculum vitae (CV), copies of degrees and transcripts of academic records, and contact information (phone, email) for at least two personal references. Relevant publications can also be enclosed, including accepted academic papers and research theses (e.g. master thesis).