PhD ceremony Mr. F. Encinas Viso: Ecology and evolution of mutualistic networks

PhD ceremony: Mr. F. Encinas Viso, 11.00 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Ecology and evolution of mutualistic networks

Promotor(s): prof. R.S. Etienne, prof. H. Olff

Faculty: Mathematics and Natural Sciences

Mutualistic interactions are ubiquitous in nature and crucial for the survival and reproduction of many species. However, it was just recently recognized that mutualistic interactions are important connectors and modulators of ecosystem function. Mutualistic communities, such as plant-pollinator communities, can be described as network of interactions between mutualistic partners (e.g. plants and animals). Using this network approach different studies have uncovered the structure and eco-evolutionary patterns in of mutualistic communities.

The question is what ecological and evolutionary processes and mechanisms are behind the assembly of mutualistic communities? We developed mathematical and simulations models combined with data analysis to explore these questions, mainly focusing in plant-animal mutualistic interactions. The main results of the thesis indicate that spatio-temporal variability is the main driver of mutualistic network structure. It is therefore, the combination of spatial structure and the variation in the timing of species interactions (i.e. phenology) what seems to mainly affect mutualistic network structure. However, the stability and diversity of these communities highly depend on the balance with other types of ecological interactions and the life-history of the species. Furthermore, main evolutonary patterns in mutualistic webs, such as evolutionary convergence and complementarity, seem to emerge from simple ecological (e.g. dispersal limitation) and evolutionary (e.g. genetic drift) processes. We conclude that: 1) neutral eco-evolutionary processes (e.g. genetic drift) should not be disregarded when studying the evolution of ecological networks and 2) that spatial processes (e.g. dispersal limitation, immigration) and phenology are essential for the assembly of mutualistic networks, and probably for ecological networks in general.