The long term properties, like coexistence and extinction, are usually determined by the
demographics of the competing species or other competitive advantages. In this dissertation
we consider the effect of conspecific support on the coexistence of species. We show that,
even if the competing species have the same demographics and interaction, their coexistence
can be destabilized by sufficient level of conspecific support. When considering large number
of species the conspecific support destabilizes the coexistance equilibrium, thus producing a
pattern of extinction and varied levels of existence. Up-scaling the model to continuous space
variable leads to a model of pattern formation via local self-activation and lateral inhibition.