Ecological Networks

Prof. Dr. Nico Blüthgen


How do ecosystems work, and why is biodiversity important for ecosystem functioning? These are the core questions behind our research. Ecosystems are characterized by numerous players (species, individuals) interacting in complex ways (ecological interaction networks). Associations may be positive for interacting species (mutualistic networks), or negative for one of them (food webs, antagonistic networks). We are trying to understand why certain pairs of species interact while others do not (partitioning). What are the benefits and costs of being a specialist? Why are consumers specialised on certain resources – because of nutrition, chemical signals, constraints? What are the consequences of specialisation for ecosystem functioning and stability? Does specialisation enhance the functional performance of the target system (functional complementarity), but represent an extinction risk? In turn, does biodiversity buffer the system against environmental disturbances (response diversity, functional redundancy)?

Our group tries to understand the mechanisms underlying the structure of ecological networks and its functional consequences, using a combination of empirical field observations, chemical analyses, experiments and modelling. We compare a broad spectrum of systems, including plant-pollinator, plant-herbivore, host-parasitoid and dung-beetle networks, as well as associations between nestmates or different species of social insects. Our studies relate natural and disturbed ecosystems in central Europe but also in tropical rainforests where biodiversity is particularly striking. The most important ecosystem risks that we target in our work are climate change, land use and biological invasions.

We will establish a chemical analytical lab (GC-MS) to understand the role of signals, pheromones, defensive compounds and nutrients in different ecological networks. We also developed conceptual tools and metrics for network analyses that are widely applicable (link).