Lecture 2: Biogeography

What drives biogeographic patterns?

Biotic and abiotic factors

Biogeographic patterns: bathymetry

Dictates light penetration

Circulation and mixing

Unique physical habitats

Vertical and horizontal boundaries

Island biogeography theory:

It’s normally easier to disperse short distances than long distances

More island: Fewer species

More Area: More species

Biogeography: waves and currents

movement of heat

dissolved oxygen

nutrients

dispersal of larvae

Example: Rimu borer

Water temperature

Determines metabolic rates

Warm water doesn’t travel far south

Humbolt current carries water to the north creating upwelling

• Nutrients and cold water from deep allows polar species to move towards the north

Ocean surface topography determined by:

Water temperature

Salinity

Atmospheric pressure

Currents