Food Web Modelling Research Group


Food webs are complex networks of trophic interactions among diverse species in ecosystems. The architecture of trophic interactions and the non-random patterning of weak and strong interactions are crucial for the stability and the persistence of ecological communities. Body size is a fundamental trait influencing prey selection and its relevance holds across ecosystems and taxa. Moreover, predator-prey body size ratios influence feeding preferences, interaction strength and predator-prey dynamics. Reduction in body size is a major response to global warming, but also other biological processes that regulate trophic interactions are modulated by temperature. For example, growth rates, developmental rates, feeding rates, swimming speed and phenology are expected to be impacted in future scenarios of global warming. Thus, better understanding the link between temperature and functional traits or processes that affect trophic interactions may represent the key for modelling the consequences of global warming on food web structure and stability. Main focus of our group is on modelling how the seasonal changes in size frequency distribution of species affect food web structure and stability. We are interested in species that shift their phenology (and alter their growth and development rates) in response to global warming. The shift in phenology alters size frequency distributions at seasonal level, thus representing a way to quantify the impact of global warming on food web structure and dynamics. Another objective of our research is investigating how heat waves affect both the intensity of energy flows and the strength of predator-prey interactions in food webs. To answer these questions we apply principles of graph theory and linear algebra, and rely on techniques as multivariate statistical analysis and individual-based modelling.


Marco Scotti
Marta Rocchi
Emmanuel Lourie

Marco Scotti: Marco has joined GEOMAR in May 2014 and his main interest is on studying the consequences of global warming on food web structure and dynamics. He investigates the effects of temperature on size frequency distribution of different species to understand whether such aspect influences food web dynamics along seasons. He is also involved in a project on neutral theory and he applies individual-based simulations to model the role the intra-species variability on food web dynamics. Personal webpage:

Marta Rocchi: Marta is a graduate student from the joint program of the University of Parma (Department of BioSciences) and the University of Ferrara (Department of Life Sciences and Biotechnology), in Italy. She is interested in qualitative modelling of complex ecological systems, food webs, and social networks. From February to April 2015 she has been supported by a DAAD fellowship and during her stay at GEOMAR she has worked on a project entitled ‘Causes and consequences of Mnemiopsis leidyi blooms in the Baltic Sea’.

Emmanuel Lourie: Emmanuel is a Master student enrolled in the International Master in Applied Ecology, Erasmus Mundus Program. He is currently studying ‘applied ecology and conservation’ at the University of East Anglia in Norwich (UK). During his stay at GEOMAR (in August and September 2015) he has investigated which relationships link species abundance to structural importance in food webs. Broadest goal of his project was identifying possible regularities in the network positions occupied by rare species in food webs.


by Marco Scotti