ESA ESA Community Ecology 2

Question 1

Which successional concept proposes that late-successional dominants inhibit early colonists but are eventually replaced by species tolerant of low resources?

Accepted Answer

Tolerance model

Answer

The tolerance model holds that species later in succession can establish under conditions created by earlier species and eventually outcompete them.

Question 2

An ecological guild is defined as a group of species that:

Accepted Answer

Exploit the same class of environmental resources in a similar way

Answer

A guild groups species by functional role in resource use, regardless of taxonomic relationships.

Question 3

The competitive exclusion principle (Gause's Law) states that:

Accepted Answer

Complete competitors cannot coexist indefinitely on a single limiting resource

Answer

Gause's Law states that two species competing for the exact same limiting resource cannot stably coexist; one will be excluded.

Question 4

Which mutualistic relationship is obligate for both partners and results in a single functional organism?

Accepted Answer

Lichens

Answer

Lichens are an obligate symbiosis between fungi and photosynthetic algae or cyanobacteria that together form a single composite organism.

Question 5

Trophic cascade effects occur when:

Accepted Answer

Changes in predator abundance indirectly alter plant biomass through effects on herbivores

Answer

A trophic cascade propagates indirect effects through food webs, typically with top predators controlling herbivores that in turn affect vegetation.

ESA - Ecological Society of America Certified Ecologist Practice Test

ESA - Ecological Society of America Certified Ecologist Practice Test

ESA ESA Community Ecology 2