Principles of Ecology II

Question 1

How are species measured in ecological communities?

Answer 1

Richness: number of OTUs present
Evenness: relative abundance of species

Question 2

Significance of evenness to coexistence

Answer 2

As you move along the x-axis of a rank abundance graph, specialization should increase and niche breadth should decrease

Question 3

Upon what is the niche concept based?

Answer 3

the idea that different members of subcommunities, also called associations, interact within niches

Question 4

What are the steps of G. Evelyn Hutchinson’s theoretical model of the niche as an n-dimensional hypervolume?

Answer 4

1. Abiotic factors envelope dimensionality for tolerances
2. Resource factors envelope dimensionality for requirements
3. Biotic factors (bionts) envelope dimensionality for associations
4. Biogeographic context (biotopes)