Guerrilla clonal growth strategy leads to amorphous pattern formation in a drylands vegetation model

Resource concentration in the vicinity of plants is observed in drylands as a result of various mechanisms, developed to cope with water scarcity. This often leads to self-organized spatial patterns that enhance drylands’ ecosystem resilience to environmental changes. Numerous vegetation dynamics models have been developed over the past few decades to study this pattern formation. Generally, they represent plant spatial spread as a diffusive process, which captures well species that reproduce via seed dispersal or through clonal growth following the “phalanx” strategy, characterized by slow, compact expansion. However, many dryland species exhibit “guerrilla” clonal growth, characterized by rapid, directional exploration of favourable areas, which is poorly captured by diffusion. To address this limitation, we introduce a novel term for lateral biomass expansion into a classical dryland model.