A BREN SEMINAR
"The Consequences of Individual Life History and Energetics
for the Dynamics, Structure and Management of
Multi-trophic Ecological Communities"
André M. de Roos
Professor of Theoretical Ecology
Institute for Biodiversity and Ecosystem Dynamics
University of Amsterdam
11:30 - 12:30
Bren Hall 1414
"All plants and animals increase in size during their lifespan and undergo qualitative changes as they mature. André de Roos has shown that fully integrating these basic biological facts into models of community and ecosystem dynamics yields very different predictions about ecological responses to management interventions. André is an engaging speaker who will effectively guide you to the insights that emerge from this growing body of ecological theory." — Bruce Kendall, faculty host
Ecological theory about consumer-resource interactions constitutes our reference framework for understanding the functioning of ecological communities and ecosystems and their responses to changing environmental conditions, natural disturbances, and human impacts. For example, consumer-resource interactions are the building blocks for community models with several trophic levels and hence provide insight about the response of communities to harvesting top predators. The mathematical foundation of consumer-resource theory, however, considers changes in species abundances only and ignores some unique and fundamental aspects of biological organisms, in particular the distinction between juvenile and adult individuals and the energetics to maintain a living body. In this presentation I will illustrate that accounting for individual life history and energetics can overturn our intuitive expectations about responses of ecological communities, even though these expectations are rigorously supported by basic ecological theory. In particular, I will show that the recovery of populations of piscivorous fish stocks, like cod, may be most effectively promoted by harvesting its focal prey species and that increasing food availability for anadromous species like salmon may be detrimental for salmon persistence.
André M. de Roos focuses his research on the relationship between processes at the level of individual life history and the dynamic patterns at the population level, probing the validity of classical population dynamic theory, which is based on unstructured models. An important topic concerns the consequences of individual energetics, such as size-dependent feeding, growth, and reproduction for population and community dynamics and, in particular, the feedback of these dynamics on the realized life history of individual organisms. He has collaborated with experimental and field ecologists to test his theoretical predictions on zooplankton, fish, and other life forms. The results of his research often seem counter-intuitive, for example, the finding that recovering piscivorous fish stocks may best be promoted by harvesting the piscivore’s main prey species. Together with Lennart Persson, he recently published a Princeton Monograph in Population Biology on the relationship between ontogenetic development and community dynamics.
NOTE: Bren seminars are hosted by Bren faculty members and are generally high-level talks about research in a particular area of environmental science and management.
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