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Rocky subtidal habitats. A sticky business. Galapagos Islands, Volcanic seamounts. Review: Potential mechanisms influencing diversity in benthic ecosystems. Physical processes (disturbance) Sediment structure Turbulence Biological processes Bioturbation Larval settling, timing
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Rocky subtidal habitats A sticky business
Review: Potential mechanisms influencing diversity in benthic ecosystems • Physical processes (disturbance) • Sediment structure • Turbulence • Biological processes • Bioturbation • Larval settling, timing • Competition • Predation
Rocky outcrops differ from sediments • Allows firm attachment of organisms • Much less burrowing into substrate • Turbulence affects attached organisms, less influence on the substrate • Feeding from surfaces and water column • Fewer places to hide • Surfaces often are 100% occupied • High local diversity
Major components of vertical walls:fleshy algaecoralline algaecolonial animals ascidians gorgonianscrustaceansspongespolychaete wormscnidarians
Major processes affecting diversity • Predation • e.g., exclosure experiments on urchins • Competition • access to currents for feeding (overtopping) • Spreading and interference • Larval settling dynamics (priority) • Disturbance dynamics • “random events” create openings • colonization probability varies with time