Existence of localized radial patterns in a model for dryland vegetation

Abstract

Abstract Localized radial patterns have been observed in the vegetation of semi-arid ecosystems, often as localized patches of vegetation or in the form of ‘fairy circles’. We consider stationary localized 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 localized radial patterns bifurcating from a Turing instability. We also present evidence for the existence of localized 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 localized radial spots and gaps. We conclude by investigating the effect of varying certain parameter values on the existence and stability of these localized radial patterns.