THE PARADOX OF THE BRYOZOANS Unravelling the relation between structure and stability of (benthic) competition networks

• Applicant: Dr. Korinna Theresa Allhoff
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics ; Bioinformatics and Theoretical Biology
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 451967415

How can diverse species assemblages exist despite fierce competition for a limited resource? Answering this fundamental question in ecology requires insights into a system’s internal organisation, such as the interactions within and between species, as well as into its external controls, such as abiotic physical disturbances. Species-rich assemblages of bryozoans provide such insights. These are sessile, colonial animals that compete for available space on the seabed. They can be regarded as a unique natural laboratory, because both the inter- and intraspecific interaction rates can be measured directly. Our goal is to decipher the relation between the internal organization of such bryozoan assemblages and their overall stability. We furthermore aim at unraveling how this relation is shaped by different disturbance regimes, such as different frequencies of seabed-iceberg collisions. We will do this by linking empirical observations of pairwise confrontations of bryozoan colonies with theoretical approaches from complex systems theory. More precisely, we will use these observations to construct what we call energy loss webs. These are networks in which the nodes represent species and the links represent biomass loss rates due to competition with other species. We will analyze these networks with a combination of mathematical tools and computer simulations to gain fundamental insights into the mechanisms that enable species coexistence and thus enhance community stability. Our project will deliver a new, observation-based and empirically tested network theory for systems governed by interference competition.

• DFG Programme: Research Grants
• International Connection: United Kingdom
• Cooperation Partners: Dr. David Barnes; Dr. Richard Law; Dr. Anje-Margriet Neutel