Species Area Relationships and Island Biogeography

Question 1

How many endangered species are on islands?

Answer 1

40%

Question 2

Why do larger islands have more species?

Answer 2

More area = more habitat diversity = more niches = more species

More area = larger population = reduced extinction risk = more species

Question 3

How much does species richness increase with area?

Answer 3

Species richness doubles with a tenfold increase in area

S = cA^z

Question 4

What is Z is true island systems?

Answer 4

0.26

Question 5

When are species-area relationships steeper?

Answer 5

For larger bodied species

For species in the tropics

Question 6

What does saturation measure?

Answer 6

The number of species on an island relative to the possible species that could occur given the pool of species on the mainland

Distant islands have less saturation

Question 7

What happens as number of species increases on an island?

Answer 7

Rates of immigration decrease

Rates of extinction increase

Question 8

How does immigration and extinction rates change with isoaltion and area of an island?

Answer 8

Immigration rates increase with increased area

Immigration rates decrease with increrased isolation

Extinction rates decrease as area increases

Extinction rates increase with increase isolation