Rocky Shore Ecosystems – Physical Drivers, Zonation & Adaptations (copy)

What are the three physical factors that most strongly structure rocky-shore communities?

Tides, wave energy, substrate microtopography.

Tides

The primary driver of community structure in rocky shores, created by the gravitational pull of the Moon and Sun.

Spring Tides

Occur during full and new moons when the Sun, Moon, and Earth are aligned, resulting in a larger tidal range.

Neap Tides

Occur when the Sun and Moon are at 90 degrees to each other, resulting in a smaller tidal range.

Wave Exposure

The extent to which coasts are subjected to wave action, influencing species diversity on rocky shores.

Supralittoral Zone

The splash zone on rocky shores, dominated by salt-tolerant lichens and exposed to air almost constantly.

Infralittoral Zone

The subtidal area which is constantly underwater, dominated by large kelps and high predation pressure.

Microhabitats

Small-scale environments that provide local refuge for organisms, such as tide-pools and crevices.

Keystone Species

Species that have a disproportionately large effect on their environment relative to their abundance, such as sea stars.

Desiccation

A key stressor in rocky shore environments, leading to adaptations in organisms to minimize water loss.

Phenotypic Plasticity

The ability of an organism to alter its physical traits in response to environmental conditions.

Asteroids

Sea stars that act as predators in rocky shore ecosystems and maintain species diversity.

Bivalves

Mollusks like mussels and oysters that filter feed and are crucial in the ecology of rocky shores.

Lunar Day

Approximately 24 hours 50 minutes, leading to an incremental delay in high tides each day.

Cages in Experiments

Used to exclude grazers like limpets, demonstrating their effect on algal cover and biodiversity.