Spatial drivers of instability in marine size-spectrum ecosystems.
J Theor Biol
; 517: 110631, 2021 05 21.
Article
in En
| MEDLINE
| ID: mdl-33600827
ABSTRACT
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.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ecosystem
/
Models, Biological
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
J Theor Biol
Year:
2021
Type:
Article