The role of competition and facilitation in structuring desert communities

Abstract

It has long been considered that abiotic factors are far more important than biotic variables in controlling the structure of desert communities. In recent years, this perception has changed because some prime examples of species interactions have come from experimental studies in desert ecosystems. Few will doubt that desert rodents present some of the best evidence for competition. Reviews also indicate that competition occurs among desert plants. This chapter focuses on some of the key competitive interactions and facilitation among desert organisms, drawn from several deserts. A great number of shrubs have been shown to have nurse plant effects on annual plants in particular, although other shrubs and geophytes may also benefit from this. Essentially, this means that the annual plants grow up under the shrub and benefit from a number of factors. The chapter also discusses indirect interactions, keystone species, priority effects and short-term apparent competition.