FLUCTUATIONS IN THE DISTRIBUTIONS AND ABUNDANCES OF SPECIES IN SUBLITTORAL KELP FORESTS IN NEW-SOUTH-WALES

Assemblages of macro- and microscopic species were sampled in two sublittoral kelp forests at each of four locations on the coast of central New South Wales. Assemblages were variable from site to site, both within and among locations. A quantified description of these habitats revealed complex patchiness at all spatial scales examined (among locations, between forests within each location and at scales of metres within forests). In addition, temporal changes in fauna and flora were variable from site to site. Of 38 taxa which showed detectable fluctuations in abundances, 26 showed trends unique to any particular forest and 11 showed consistent patterns in both forests within a location. Only juvenile kelp (Ecklonia radiata) showed similar fluctuations in abundance in both forests in most locations. Thus, the structure and dynamics of these systems vary and do not conform to predictions of simple models about processes in habitats dominated by one or a few large organisms. We conclude that when kelp forests are described using quantitative data at several spatially replicated scales, few general conclusions can be made about the structure of these assemblages. The implications of these results for studies of the effects of human and natural perturbations on these systems is discussed.