ESA ESA Community Ecology 1

Question 1

Which term describes the sequential change in species composition of a community over time following a disturbance that leaves soil intact?

Accepted Answer

Secondary succession

Answer

Secondary succession occurs on sites where soil remains after a disturbance, allowing faster colonization than primary succession.

Question 2

The intermediate disturbance hypothesis predicts that species diversity is highest at:

Accepted Answer

Intermediate disturbance frequencies

Answer

Intermediate disturbance prevents competitive exclusion by dominants while still allowing recolonization by early successional species, maximizing diversity.

Question 3

A keystone species is best defined as a species that:

Accepted Answer

Exerts a disproportionately large effect on community structure relative to its abundance

Answer

A keystone species has an ecological impact far greater than would be predicted from its abundance or biomass alone.

Question 4

Which index combines both species richness and evenness to quantify community diversity?

Accepted Answer

Shannon-Wiener index

Answer

The Shannon-Wiener index (H') accounts for both the number of species and the relative abundance of each species in a community.

Question 5

Interspecific competition in which one species directly harms another through toxin release is called:

Accepted Answer

Allelopathy

Answer

Allelopathy refers specifically to chemical inhibition of one plant (or microbe) by another via release of secondary metabolites.

ESA - Ecological Society of America Certified Ecologist Practice Test

ESA - Ecological Society of America Certified Ecologist Practice Test

ESA ESA Community Ecology 1