Biography & Abstract



Prof. Bastiaan Ibelings

University of Geneva 



Bastiaan Ibelings is a microbial ecologist with 30 years of experience in aquatic research and consultancy, with an emphasis on cyanobacteria, microalgae and parasitic chytrid fungi. Presently I am Ordinary Professor in Microbial Ecology at the Department for Aquatic and Environmental Sciences and the Institute for Environmental Sciences at the University of Geneva. My studies on phytoplankton biodiversity vary from the population to the community and whole ecosystem level. Whenever possible I integrate processes in ecology and evolution and my interests range from the evolutionary origin of new microbial species, all the way up to the importance of phytoplankton diversity for (alpine) lake ecosystem services. Identifying the ecological and evolutionary processes that determine plankton community assembly is an important pre-condition to understand and ultimately predict the effects of climate change on aquatic ecosystems. Because of the direct link between functional diversity and ecosystem functioning, our efforts are focused on studying trait diversity in plankton communities. I believe that the most recent developments in instrumentation and IT-technology will allow us to study environmental change where it unfolds, the lake ecosystem, at the fine temporal and spatial scales that are relevant to plankton. In this I work intensively collaborate with colleagues worldwide, united in the grassroots network GLEON, where I have been elected as co-chair.  I am (co)author of over 100 peer reviewed publications and have written numerous reports on water management and lake restoration efforts. The biggest threat to aquatic systems worldwide is still eutrophication and part of my research efforts focuses on the consequences of harmful cyanobacterial blooms for the lake-foodweb and associated risks for humans. Previous positions I held included Senior Scientist at the Netherlands Institute of Ecology, Group Leader at Eawag and Program manager Lakes at the Netherlands Institute for Inland Water Management. I have (co)supervised more than 20 PhD students and (co)obtained the funding for all these projects.  At the University of Geneva I teach different courses at the Bachelor level for students in Biology and Earth Sciences and I have developed new courses for the interdisciplinary Master – MUSE -  taught within the Institute for Environmental Sciences.

Title: From vials to lakes: on the role of environmental complexity for eco-evolutionary feedbacks in microbial communities
Abstract: In this presentation I will explore the importance of environmental complexity  - somewhat akin landscape heterogeneity - for microbial biodiversity. In particular I will seek to discuss the feedbacks between (i) environmental complexity, (ii) the evolution of biodiversity and (iii) species co-existence and the long term maintenance of biodiversity in face of ecological processes like competition and parasitism. I will cover spatial scales ranging from micrometers in glass vials to hundreds of meters in deep alpine lakes and temporal scales from hours to decades. What creates complexity of the environment, which processes contribute? Complexity, amongst others is created through activity of the microbes themselves, so that one could say that it is life itself that generates the conditions for biodiverse ecosystems - through a process known as niche construction. In a heterogeneous and dynamic landscape, diversity is maintained through frequency dependent selection and non-transitivity – as in the game rock-paper-scissors. There are no overall winners which dominate the microbial community under all conditions1.  In lakes the indirect effects of climate warming have greatly altered the physical structure of the watercolumn and have enhanced heterogeneity, arguably allowing the co-existence of more phytoplankton species in alpine lakes at present than in the past2. Climate change also plays a critical role in the interactions between phytoplankton and parasitic – chytrid – fungi. These host x parasite interactions are crucial for the maintenance of genetic diversity in ecosystems, but here climate change effects on lake ecosystems seem to negatively impact genetic biodiversity3. In short, I will discuss questions concerning the evolutionary and ecological processes that create and maintain microbial biodiversity as well as the role of a changing environment on these  eco-evolutionary feedbacks.