Hanski Ch. 4

Question 1

species that colonize islands

Answer 1

adapt and become more specialized over time, increasing risk of extinction

Question 2

taxon cycle

Answer 2

existing species become specialized and increase risk of extinction while new generalists arrive to compensate for extinction

Question 3

what increase invasive species?

Answer 3

propagule pressure

Question 4

2 components of propagule pressure

Answer 4

number of individuals introduced into a new area during one event (propagule size)
number of introduction or release events (propagule number)

Question 5

high propagule pressure increased probability of

Answer 5

successful establishment of the invading species

Question 6

2 situations for assisted migration

Answer 6

small isolated populations, suffer from reduced genetic variation and inbreeding depression
species in fragmented landscapes, can’t colonize unoccupied habitat

Question 7

climate warming expands species distribution, increases _____ and reduces _____

Answer 7

local species richness
differences in species composition between communities