100 % / starting July 2026 or later
The Physiological Plant Ecology group at the Department of Environmental Sciences at the University of Basel in Switzerland invites applications for a four-year PhD position in physiological tree ecology within a project fully funded by the Swiss National Science Foundation (SNFS). The project will be conducted in collaboration with researchers from the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL).
All tree species reach upper elevational and latitudinal distribution limits that are primarily caused by species-specific low temperature thresholds beyond which a given species cannot persist and reproduce sustainedly. A profound knowledge of these low temperature limits and their underlying biological mechanisms is necessary to establish mechanistic models for tree distribution and growth that will improve our predictions of tree species’ range-shifts as well as productivity changes within their current ranges with future climate warming. The cold limitation of tree growth may be driven by tree hydraulic constraints induced by restricted root water uptake at low soil temperatures. However, our current knowledge about the significance of soil temperatures for productivity and distribution of temperate trees is very limited, and cold soil effects are still not well represented in current tree hydraulic models. In this project, we will apply an innovative combination of experimental studies with tree seedlings and observational field records on mature trees to assess the physiological impact and ecological significance of low root temperatures for the hydraulic relations and growth of common European temperate tree species.
Your assignments
The PhD candidate will be responsible for planning and executing experiments with seedlings of different European tree species to identify physiological mechanisms and biological consequences of the cold-temperature restriction of root water uptake. These experiments will specifically investigate the significance of aquaporin facilitated root water transport as a cause for the different cold sensitivities among species using stable isotope labelling and determine species-specific low temperature thresholds of root water uptake using continuous sap flow measurements. In addition, the PhD candidate will conduct in situ measurements of soil and air temperatures in forests across elevational transects in the Swiss Alps to functionally relate the experimentally identified hydraulic cold thresholds to the thermal conditions at the natural upper elevational limit of the investigated tree species. In the second half of the project, the team will be extended by a postdoc position, who will focus on assessing the effects of cold soils on the hydraulic relations and growth of mature trees. The PhD candidate is supposed to jointly contribute to the respective field measurements at the long-term alpine treeline research site Stillberg in Davos, Switzerland. Finally, the PhD candidate will also contribute to teaching within the Physiological Plant Ecology group.
Your profile
We are looking for a highly motivated candidate with a self-organized and solution-oriented work attitude, strong communication and organizational skills, the ability to work in a team and the commitment to an inclusive workplace are essential. Very good written and spoken English is mandatory. Applicants should hold a MSc degree in botany, ecology, forest science, environmental science or related fields, and have a basic knowledge of plant physiology. Experience with plant ecophysiological methods and a basic understanding of electrical engineering are an asset. Candidates should be able to prepare and conduct greenhouse experiments with tree seedlings and independently conduct statistical analyses with R. Candidates should be also willing to conduct field work in subalpine terrain over a longer period.
We offer you
A fully-funded PhD position for four years in a dynamic research group with an excellent research infrastructure in the international and interdisciplinary Department of Environmental Sciences at the University of Basel in Switzerland. You will join a supportive, collaborative and cooperative working environment and will have the opportunity to be integrated in established international research net-works. Internationally competitive salaries and social benefits are provided according to the rules of the University of Basel. The University of Basel (http://www.unibas.ch) is the oldest university in Switzerland and is located at the border between Switzerland, France and Germany. A PhD school including courses to improve hard and soft skills, as well as career development opportunities are available.
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Application / Contact**
Please upload your application via our online platform, including a motivation letter stating your research interests and motivation for applying for the position (max. 1 page), a CV, a copy of your MSc degree, and the names and contact details of 3 references. We especially encourage applications from women and from persons underrepresented in academic research. Review of applications will begin on May 11, 2025 but will continue until the position is filled. Only online applications submitted through the recruiting platform will be considered. For further questions please contact Prof. Dr. Günter Hoch (guenter.hoch@unibas.ch) and visit https://eco.duw.unibas.ch/en/ for information about the Physiological Plant Ecology research group.