| The abundance and diversity of the flora and fauna were determined on the topsides and undersides of 60 randomly-selected boulders of various sizes in March-May and August-September 2004 within a kelp forest in central California. Two hundred twenty-two (222) taxa [12 algae, 9 attached invertebrates, 46 large mobile animals (>0.5mm), and 155 small mobile animals (<0.5mm)] were identified. The topsides hosted a completely different set of organisms than the undersides. The underside mobile fauna was almost twice as dense as the topside fauna, and had higher diversity. Abundance of attached organisms varied with boulder size and location while mobile organisms varied more by time of sampling. Topsides of small boulders had higher densities of total animals, the snail, Lithopoma gibberosum, and higher cover encrusting sponge than densities of large boulders. The undersides of small boulders had higher cover of encrusting coralline algae than large boulders. |
