Spatial patterns of coral occupants arising from propagule redirection

Many habitats are fragmented and consist of patches scattered throughout a landscape.  Within these patches, many organisms are distributed heterogeneously.  Differences in distribution are often attributed to factors that affect the settlement process, such as habitat availability, quality, and the presence of conspecifics.  The addition of habitat can influence settlement dynamics in two ways:  1) increasing the number of total settlers in proportion to the increase of habitat (field of dreams), and 2) redirecting settlers away from existing habitat (propagule redirection).  However, even if neighboring habitat affects initial patterns, the dynamics of the system could cause the initial pattern to fade so that the resulting pattern is no different than if the system was settled in a manner similar to field of dreams.  We model both settlement and post-settlement dynamics to determine the situations in which redirection patterns are retained and the distribution of organisms throughout the patches is heterogeneous and when initial patterns fade to a homogeneous distribution of organisms.  Redirection patterns are maintained in equilibrium when the system is not saturated (low settler supply, high density dependence, and longer times between settlement events).  However, the resulting spatial distribution of organisms is homogenous when the system is saturated due to a large supply of settlers, high density dependence, or rapid settlement events.  Therefore, in certain conditions, heterogeneity in species distribution can be due solely to habitat configuration, rather than aspects such as quality and attraction to conspecific residents.