Interactions - Consumer-Resource

Question 1

Consumer-resource interactions

Answer 1

One species exploits another, one benefits while the other species is harmed. Dynamic!

Question 2

Competition

Answer 2

Both species are harmed

Question 3

Amensalism

Answer 3

One is harmed while the other is unaffected

Question 4

Exploitation

Answer 4

One benefits while the other is harmed

Question 5

Commensalism

Answer 5

One benefits while the other is unaffected

Question 6

How can we model the predator-prey cycle?

Answer 6

Lotka-Volterra model for cyclic predator-prey interactions. Assumes exponential growth of the prey population, limited only by consumers.

Growth rate of prey pop = r(#prey) - (rate of predation)(#prey)(#predators)

Growth rate of predator pop = (rate of conversion of food to offspring) - (mortality rate)
= (food conversion factor)(rate of predation)(#prey)(#predators) - (death rate)(#predators)

Question 7

What are the shortcomings of the Lotka-Volterra model?

Answer 7

(1) Time lags in predator/prey response
(2) Carrying capacities for predator/prey populations
(3) No functional response in predator

Question 8

What is necessary for the predator-prey cycles to occur?

Answer 8

(1) Destabilizing factors to drive the cycles (e.g. time delay in the response of a population to a change in food supply)
(2) Stabilizing factors to balance them out

Question 9

Stabilizing factors

Answer 9

(1) Refuge–security to survive
(2) Predator inefficiency
(3) Density-dependent limitation
(4) Alternative food source
(5) Reduced time delays in response to changes in food abundance
(6) Influx of new replacement individuals

Question 10

What are the types of refuge?

Answer 10

(1) Space
(2) Numbers
(3) Morphology
(4) Behavior
(6) Size