Food web ecology

Food web ecology

Anthropogenic activities continue to impact the functioning and the biodiversity of freshwater ecosystems worldwide. With most of these activities now co-occurring, ecosystems are facing pressures from multiple stressors. The spatial or temporal co-occurrence of stressors may produce synergistic, antagonistic or additive ecological effects and thus influencing several biological compartments of freshwater ecosystems. Such novel effects are notoriously difficult to quantify using biodiversity-based assessment approaches, as they ignore interactions among biological compartments. Furthermore, classical approaches assume that the presence of a desired level of diversity also implies good ecosystem functioning but this assumption is often not met under realistic conditions. Hence, freshwater managers are becoming increasingly aware that classical assessment needs to be complemented by novel approaches that consider functional targets including ecosystem processes. The study of food webs provides a promising approach as food webs explicitly consider ecosystems functions to be mediated by biological communities and thus link classical, taxonomically grounded research with fluxes of organic matter.

Our research focuses on how human perturbations affect food web topology and consumer-resource interactions of lotic ecosystems. Building on that, we are working on indicators to assess the functional status of lotic ecosystems and to inform management authorities on how to mitigate human impacts on ecosystem material cycling. Our work involves a significant field component, including large-scale as well as field mesocosm studies. We use a range of techniques but primarily combine stable isotopes, mixing model analysis and estimates of ecosystem productivity and respiration to quantify organic matter fluxes.

Head of the research group: Dr. Mario Brauns

Current projects

Wilde Mulde


Holtemme River

Shoreline development at a lowland lake


Mario Brauns (Researcher)

I am a research scientist at the Department River Ecology since 2010. My research interests focus on developing and applying indicators of ecosystem function derived from food webs to assess the impacts of human activities, in particular hydromorphological degradation and invasive species. More information can be found on my personal web page.

Laura Meier (PhD)

Laura is a joint PhD student together with the Department Ecological Modelling since 2017. Her PhD research comprises the development of coupled food web models of river networks. Special interest is in how long-distance stressors interact with the passive drift of organisms and how this affects riverine food webs. More information can be found on her personal web page.

Romy Wild (PhD)

Romy joined the working group in 2012 after completing her M.Sc in Biology and in Marine Environmental Protection. Her PhD research quantifies the effects of agricultural land use on the functioning of temperate stream ecosystems in the HECTARE project. Romy is interested in applied research on the dynamics of structure and functioning of aquatic communities under human pressure. More can be found on her personal web page.

Sven Bauth (Technician)

Sven is responsible for organising and conducting macroinvertebrate samplings in streams and rivers. He is involved in the taxonomic mentoring of graduate and undergraduate students. Apart from that, he is the captain of the research-vessel ALBIS that we use for sampling in large navigable rivers.

Ines Locker (Technician)

Ines coordinates and does the sample and data analysis of 13C/12C and 15N/14N in organic solid samples. Her duties include preparing standards and samples, setting up runs on the solid sample EA-IRMS system, creating templates for runs, importing results into the lab's database, and general laboratory maintenance.