Metapopulations

Question 1

Explain patchy habitats

Answer 1

most obvious is islands. “islands” = area of suitable habitat surrounded by areas of unsuitable.
ex. lakes, sky islands, obligate symbionts (parasite hosts

Question 2

What are the 3 categories of patchy populations and explain

Answer 2

1. mainland-island (source sink) = no danger of extinction, the mainland acts as a source population to the islands that can go extinct or are extinct
2. panmictic population (with spatial distribution) = have some physically separate, but enough migration among them that none are at risk of extinction
3. metapopulation = no subpopulations that can be permanent, each patch has substantial risk of extinction from any year, connected with one another that if go extinct can still become recolonized

Question 3

Explain the dynamics of metapopulations

Answer 3

are at level of birth and death of individuals as well as colonization and extinction of entire populations

Question 4

how are metapopulations colonized

Answer 4

they don’t have a mainland that colonizes others, they are all colonized by other islands

Question 5

Explain the extinct of individual sub-populations vs. the whole metapopulation

Answer 5

individual sub-populations blink into and out of existence while the metapopulation as a whole remains intact

Question 6

metapopulation dynamics =

Answer 6

balance of probabilities of migration and local extinction

Question 7

what does p mean in the metapopulation dynamics

Answer 7

proportion of patches currently occupied

Question 8

start with ____ of extinction in metapopulation dynamics

Answer 8

absence

Question 9

Assume migration probability is proportional to both the…

Answer 9

proportion occupied, p, and the proportion not occupied, 1-p

Question 11

What happens to the metapopulation graph if m>e

Answer 11

if migration exceeds extinction, then concave down parabola and vise versa

Question 12

P=0 and p= 1-3/m on the metapopulation dynamics graph

Answer 12

p=0 is an equilibrium and is the unstable value when m>e
p=1-3/m is an equilibrium and is stable value when m<e

Question 13

Consequence when m>e and e>0

Answer 13

m>e overall population is viable
some sub-populations empty when e>0

Question 14

What are the 2 points for a true metapopulation

Answer 14

1. some sites are unoccupied
2. unoccupied sites are potentially occupiable

Question 15

What are the 6 assumptions of metapopulations

Answer 15

1. suitable habitat occurs in discrete patches
2. the population is at least temporarily reproductive
3. subpopulations have substantial risk of extinction
4. subpopulations not so isolated that recolonization is impossible
5. dynamics are not synchronized across populations
6. patches are more or less identical (in terms of probability of extinction and colonization)