Andersen, T. . University of Oslo, tanderse@bio.uio.no

 
PELAGIC FOODWEB RESPONSES TO NUTRIENT ENRICHMENT: INVERSE MODEL ANALYSIS OF MASS FLOWS IN MESOCOSM GRADIENT EXPERIMENTS
 
A long-standing goal of food web studies is to identify regular and repeatable patterns in community level responses to external perturbations. The kind of inherently multi-dimensional information implied by a community response obviates a need for efficient ways of representing the dynamical state of a food web. Such representations may range from qualitative digraphs to fully mechanistic state-space models; - with progressively increasing demands for input parameters and validation data. The network structure representing the flows of energy and major elements between main food web components can be considered a compromise between these two extremes. The reconstruction of mass-balanced flow networks can be formulated in terms of general concepts from linear inverse theory. This presentation will show how flow networks can be used to organize measurement data and compare plankton community responses in mesocosm experiments, with specific examples taken from an enrichment gradient experiment performed on the coast of Norway, NE Atlantic Sea (as part of the EU-MAST III project COMWEB). The potential for using flow networks as basis for low-dimensional indices or aggregated measures for comparing food web structures will be briefly discussed.
 
Day: Thursday, Feb. 4
Time: 02:15 - 02:30pm
Location: Hilton of Santa Fe
 
Code: SS51TH0215E