Factors influencing structure and dynamics of subtidal assemblages on walls at a South Eastern Australian Rocky Reef
Assemblages on vertical surfaces at a Rocky Reef at Flinders Islet, South Eastern Australia differ in structure. Tall wall (> 4 m) assemblages are highly diverse, while low wall (1-2 m) assemblages are characterised by low diversity. Abundance of the sea urchin Centrostephanus rodgersii is lower on tall than on low walls. Recruitment, succession and sea urchin grazing were found to differ among wall types and contribute to the observed different assemblages. A change in habitat lead to a divergence of assemblages, however there was no convergence of assemblages and no carry-over effect of the original habitat. Tall and low walls represent two different habitats that may effectuate two alternative community states, the low wall assemblage being less stable than the tall wall assemblage diverging soon when habitat changes during succession.