RECOLONIZATION AND SUCCESSION IN SOFT-SEDIMENT INFAUNAL COMMUNITIES -THE SPATIAL SCALE OF CONTROLLING FACTORS

Succession in marine soft-sediment habitats has been studied extensive ly and several general models of successional dynamics have been devel oped. However, few researchers have addressed how successional dynamic s may change over different spatial scales. Here we extend a model tha t focuses on the factors that control recolonization and succession. T hese factors comprise three levels of a hierarchy which include enviro nmental conditions, Life history and population processes and biotic i nteractions. Using this hierarchical framework, we consider the spatia l scales at which different factors operate, and argue that the relati ve mix and intensity of factors controlling succession change at diffe rent spatial scales. As a result, successional dynamics may vary consi derably as the spatial scale of disturbance increases. At small scales , factors at each level of the hierarchy are important. The greater po tential for biotic interactions at this scale may be particularly crit ical. At meso- to large scales, population processes and environmental conditions have the most influence on successional dynamics. Due to t hese differences, responses to small-scale (less than or similar to 1 m(2)) as well as large-scale (greater than or similar to 1 hectare) di sturbances may be quite variable. Within this range (greater than or s imilar to 1 m(2) less than or similar to 1 hectare), short- and long-t erm responses to disturbance may be relatively more predictable and co nform to current models of succession in soft-sediment habitats.