Lecture 7 Community Ecology

Question 1

What is the equilibrium explanation?

Answer 1

Holds that spatial heterogeneity promotes diversity by reducing niche lap

Question 2

What is the non equilibrium explanation?

Answer 2

holds that temporal heterogeneity that promtes diversity by interrupting competitive exclusion

Question 3

What is the intermediate disturbance hypothesis?

Answer 3

Species richness is the highest with IDH occuring.

Only tolerant species persist at high frequency;
only competitive species persist at low frequency

Question 4

how can spatial heterogeneity promote diversity

Answer 4

by limiting niche overlap.

Question 5

How can temporal heterogeneity can promote diversity

Answer 5

by interrupting competitive exclusion.

Question 6

biodiversity usually correlates with what?

Answer 6

increased production

Question 7

What does a food web summarize?

Answer 7

feeding relations in a community

Question 8

How is a interaction web different from the food web?

Answer 8

Interaction web can include non feeding relations alongside feeding relations

Question 9

What are indirect interactions?

Answer 9

occurs when one species has an effect on another through an intermediate species

Question 10

What does a trophic cascade describe?

Answer 10

the direct negative effect of an apex predator on its prey, and indirect positive effect of the apex predator on basal prey

So in wolves, elk and willows example, the willows benefit when the elk is preyed upon