Journal article
Spatial drivers of instability in marine seize spectrum ecosystems
Yangzhou University1
University of York2
Dynamical Systems, Department of Applied Mathematics and Computer Science, Technical University of Denmark3
Department of Applied Mathematics and Computer Science, Technical University of Denmark4
Centre for Ocean Life, National Institute of Aquatic Resources, Technical University of Denmark5
National Institute of Aquatic Resources, Technical University of Denmark6
Size-spectrum models are a recent class of models describing the dynamics of a whole community based on a description of individual organisms. The models are motivated by marine ecosystems where they cover the size range from multicellular plankton to the largest fish. We propose to extend the size-spectrum model with spatial components.
The spatial dynamics is governed by a random motion and a directed movement in the direction of increased fitness, which we call ‘fitness-taxis’. We use the model to explore whether spatial irregularities of marine communities can occur due to the internal dynamics of predator-prey interactions and spatial movements.
This corresponds to a pattern-formation analysis generalized to an entire ecosystem but is not limited to one prey and one predator population. The analyses take the form of Fourier analysis and numerical experiments. Results show that diffusion always stabilizes the equilibrium but fitness-taxis destabilizes it, leading to non-stationary spatially inhomogeneous population densities, which are travelling in size.
However, there is a strong asymmetry between fitness-induced destabilizing effects and diffusion-induced stabilizing effects with the latter dominating over the former. These findings reveal that fitness taxis acts as a possible mechanism behind pattern formations in ecosystems with high diversity of organism sizes, which can drive the emergence of spatial heterogeneity even in a spatially homogeneous environment.
Language: | English |
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Year: | 2021 |
Pages: | 110631 |
ISSN: | 10958541 and 00225193 |
Types: | Journal article |
DOI: | 10.1016/j.jtbi.2021.110631 |
ORCIDs: | Thygesen, Uffe H. and Andersen, Ken H. |