Tidal Zones Flashcards
Factors that influence distribution of species along seashore
Gradient, physical conditions and biological interactions.
Zonation
Spatial arrangement of different species or communities within the ecosystem.
Factors affecting coastal zonation
Tidal inundation, wave exposure, salinity, wind, temperature and substrate.
Supralittoral zone
Upper shore, long periods exposed to air. Home to barnacles and periwrinkles.
Periwrinkle
Littorina littorea
Barnacles
Cthalamus stellatus
Littoral zone
Mid shore, fluctuating conditions. Home to red algae and lettuce algaes.
Red algae
Ascophylum nodosum
Lettuce algae
Fucus vesiculosus
Infralittoral zone
Lower shore, mostly submerged conditions (more constant). Home to mussels and oysters and racks.
Mussels
Mytilus edulis
Oysters
Ostrea edulis
Rack seaweed
Fucus serratus
Succession
Ecological communities undergo a process of changes over time ultimately leading to a stable “climax” community.
Primary succession
Occurs in areas previously devoid of life.
What causes succession?
Disturbances, glacier melts, storms, volcanic eruptions etc.
Secondary succession
Occurs in areas where a community has been disturbed.
Pioneer species in coastal habitat
Ulva lutucea - green algae
K strategy species
Grow slowly and produce fewer offspring, but more competitive, normally dominate later in succession.
R strategy species
Rapidly grow and multiply, not competitive and usually dominate in newly disturbed areas.
Climax community
Stable community with little to now changes in inhabitants, populations and disturbances are minimal.
Why are tidal zones never really climaxed?
The force of sea storms and tidal influence is constantly disturbing the habitat.
