SCALE-DEPENDENT BENTHIC RECOLONIZATION DYNAMICS - LIFE STAGE-BASED DISPERSAL AND DEMOGRAPHIC CONSEQUENCES

Soft-sediment recruitment dynamics are dependent upon two sources of c olonists; larvae transported from the water column and post-settlement movement of juvenile and/or adult life-stages across the seabed. Diff erences in the relative dispersal ability of the different life-stages into disturbed patches of habitat should vary predictably with the sp atial scale of the disturbance. Smaller patches with a greater edge:su rface area ratio should be more influenced by the post-settlement colo nist pool than larger patches possessing a smaller edge:surface area r atio. A life stage-based recolonization model, using a Polydora cornut a life table, has been developed to describe how differences in the im migration rates of larvae, juveniles and adults can influence within-p atch recovery times. Model results indicate that immigration of adult stages into disturbed patches has the least influence on patch recover y time. In contrast, post-settlement juvenile stages generally has a p ronounced effect on patch population dynamics. Experimental evidence o f scale-dependent migration of different Life-stages to disturbed patc hes is also presented for the spionid polychaete Boccardia syrtis. Fut ure research on scale-dependent recolonization dynamics in soft-sedime nt habitats should focus on acquisition of within-patch demographic da ta in order to more fully understand the importance of post-settlement life-stage movement in regulating population and community dynamics.