Existence of localised radial patterns in a model for dryland vegetation

TL;DR

This paper demonstrates the existence and stability of localized radial vegetation patterns in a dryland ecosystem model, combining analytical bifurcation analysis and numerical simulations to understand pattern formation.

Contribution

It proves the existence of three classes of localized radial patterns bifurcating from a Turing instability and explores their stability and parameter dependence.

Findings

Existence of three classes of localized radial patterns bifurcating from Turing instability

Numerical evidence for localized gap solutions near homogeneous instability

Parameter variations affect the existence and stability of patterns

Abstract

Localised radial patterns have been observed in the vegetation of semi-arid ecosystems, often as localised patches of vegetation or in the form of `fairy circles'. We consider stationary localised radial solutions to a reduced model for dryland vegetation on flat terrain. By considering certain prototypical pattern-forming systems, we prove the existence of three classes of localised radial patterns bifurcating from a Turing instability. We also present evidence for the existence of localised gap solutions close to a homogeneous instability. Additionally, we numerically solve the vegetation model and use continuation methods to study the bifurcation structure and radial stability of localised radial spots and gaps. We conclude by investigating the effect of varying certain parameter values on the existence and stability of these localised radial patterns.