Prof. Dr. Thomas Posch – Symbiotic interactions in freshwater food webs

Prof. Dr. Thomas Posch (ORCID  ORCID 0000-0001-5145-3761)
Adjunct Professor, Group Leader, Symbiotic interactions in freshwater food webs
posch@limnol.uzh.ch

About Me
As a group leader and Adjunct Professor at the University of Zurich’s Limnological Station, I focus on studying the interactions between unicellular eukaryotes (protists) and heterotrophic bacteria within aquatic microbial food webs. Principally, we find in this small world any kind of ecological relationship: predation, parasitism, competition, mutualism. The interaction between protists and bacteria is often seen as a classical predator-prey relationship, disregarding the various “side-effects” concerning interspecific competition, shifts in nutrient regeneration, changes in nutrient availability and changing vulnerability to parasites. On the other hand, environmental parameters (e.g., lake warming) have a strong influence on protists-bacteria interactions. My research group studies these diverse relationships in lab-experiments and field-studies in alpine lakes. Our research site is primarily Lake Zurich where we also follow the tradition of long-term monitoring (for 60 years).

Research Interests
Lake warming
Symbiosis between prokaryotes and protists in freshwater systems
Ecology of the cyanobacterium Planktothrix rubescens
 

Lab Overview
We utilize a broad set of biological methods (from microscopy to genomics) in combination with physico-chemical approaches (environmental parameters).
We work with isolated and cultivated organisms, as well as with in situ samples. Therefore, a combination of classical microscopy techniques with molecular approaches is needed to reach a high taxonomical resolution. Our monitoring programs are based on weekly / biweekly sampling campaigns on Lake Zurich and other small lakes in the region. Besides biological samples, we investigate a wide set of physico-chemical parameters of the studied ecosystems.

Expertise
Aquatic Microbial Ecology
Limnology
Protistology
Microscopy
Taxonomy

Limnological Station UZH
Other group leaders at the Limnological Station
Prof. Dr. Jakob Pernthaler
Dr. Adrian-Stefan Andrei