island biogeography Flashcards
species richness depends on?
immigration rates, extinction rates, island size, degree of isolation
(biological interactions occur but are unimportant - pred. & comp. )
(t/f) community has an equilibrium richness
true = s with arrow head on top
explain immigration rates
- highest when few species present (every new arrival will be a new species)
- lowest when species pool is exhausted (no other species left to colonize island)
rate of species decreases as number of species increases
explain extinction rates
- lowest when few species present (less competition for resources & fewer predators)
- highest when # of species in a community are high
explain community in equilibrium
- stable equilibrium
- extinction = immigration
define dynamic stable equilibrium
equilibrium - richness remains constant over time
dynamic - identity of species changing at s
stable - return to s following a disturbance
explain effects of island size
- large island affects extinction
- large islands support large population (e is small)
- small islands support small population (e is large)
- s increases with island size
explain effects of isolation
- isolation affects immigration
- near islands have more immigrant
- far island have fewer immigrant
- s decreases with increases isolation
give 2 examples of richness increasing with island size
- east indies birds - bird richness increased w/ island size
- fish in Wisconsin lake - # of fish species per lake increases w/ lake area
define biogeography
study of the relationship between geography and species distribution and abundance
after succession what other factor affects community structure?
biogeography
define islands
discrete habitats separated by uninhabitable space
define island achipelago
island chains where there are a number of island differing in geographic characteristics
(t/f) single plants and animals can be an island
true
