Metapopulations

Question 1

What are metapopulations?

Answer 1

Connected populations

Question 2

Explain Huffaker’s first experiment

Answer 2

1 host, 1 prey, 1 predator
1 orange, 1 citrus mite, 1 predatory mite
The citrus mite eats from the orange and the predatory mite eats the citrus mite = unstable predator prey oscillations on a single orange that results in extinction

Question 3

Explain Huffaker’s second experiment

Answer 3

Multiple oranges used
Dispersal distances controlled
Predator-prey coexistence can be facilitated by spacial structure and introduces some stability
“Rescue effect” by immigration from other patches

Question 4

What is Levin’s Model (equation)?

Answer 4

The dynamics of patch occupancy:
dP/dt = cP(1-P) - eP

P = occupied patches
1-P = unoccupied patches

Question 5

What is the equilibrium patch occupancy rate?

Answer 5

P = 1-(e/c)

If e>c then p

Question 6

What are the assumptions of Levin’s Model?

Answer 6

• Infinite number of equally connected patches
• All patches are equivalent
• Colonisation is not affected by distance
• Patches in a binary state

Question 7

What happens if habitat patches are removed?

Answer 7

Colonisation decreases, it becomes more likely that a population will collapse

Question 8

Why should we promote “wildlife corridors”?

Answer 8

Colonisation increases, stabilises and it increases the persistence of the species