title: A new dimension: Evolutionary food web dynamics in two dimensional trait space.
abstract: Species within a habitat are not uniformly distributed. However this aspect of community structure, which is fundamental to many conservation activities, is neglected in the majority of models of food web assembly. To address this issue, we introduce a model which incorporates a second dimension, which can be interpreted as space, into the trait space used in evolutionary food web models. Our results show that the additional trait axis allows the emergence of communities with a much greater range of network structures, similar to the diversity observed in real ecological communities. Moreover, the network properties of the food webs obtained are in good agreement with those of empirical food webs. Community emergence follows a consistent pattern with spread along the second trait axis occurring before the assembly of higher trophic levels. Communities can reach either a static final structure, or constantly evolve. We observe that the relative importance of competition and predation is a key determinant of the network structure and the evolutionary dynamics. The latter are driven by the interaction-competition and predation-between small groups of species. The model remains sufficiently simple that we are able to identify the factors, and mechanisms, which determine the final community state.
authors.affiliation: CvO University Oldenburg, ICBM, Carl-von-Ossietzky-Strasse 9-11, 26111 Oldenburg, Germany. Electronic address: daniel.ritterskamp@outlook.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Ritterskamp
authors.affiliation: CvO University Oldenburg, ICBM, Carl-von-Ossietzky-Strasse 9-11, 26111 Oldenburg, Germany. Electronic address: daniel.bearup@uni-oldenburg.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bearup
authors.affiliation: CvO University Oldenburg, ICBM, Carl-von-Ossietzky-Strasse 9-11, 26111 Oldenburg, Germany. Electronic address: blasius@icbm.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Blasius
mesh_terms: D005075:Biological Evolution; D058448:Biota; D003198:Computer Simulation; D005247:Feeding Behavior; D020387:Food Chain; D008954:Models, Biological; D011157:Population Dynamics
keywords: Evolutionary dynamics; Higher dimensional trait space; Large community-evolution models; Network structure; Spatial food webs