Ecological Succession: Stages, Climax Theories, and Modern Dynamics

All flashcards

What is ecological succession?

The process by which the species composition of an ecological community changes over time.

How do primary and secondary succession differ?

Primary succession begins in a newly available habitat with little or no life and little developed soil. Secondary succession follows disturbance to a pre-existing community and may benefit from remaining soil, seeds, or organisms.

What is nudation?

The creation or presence of a bare area with little or no life or organic matter; it can occur after a disturbance in secondary succession.

What does ecesis mean?

The establishment and initial growth of vegetation after propagules reach a site.

What is the reaction stage?

A stage in which organisms change habitat conditions—for example, by adding humus or creating shade—and those changes can favor replacement of one plant community by another.

Quiz questions

1. A plant seed reaches a site, but unsuitable soil prevents it from surviving or growing. Which process is limiting establishment?Answer: Environmental filtering
2. Which is an example of autogenic change during succession?Answer: Plants add litter that changes soil organic matter.
3. Why can fire and grazing help maintain biodiversity in some old-growth grasslands?Answer: Some grassland species are adapted to resprout after aboveground disturbance.
4. Which contrast between Clements and Gleason is accurate?Answer: Clements emphasized predictable development toward climax; Gleason emphasized individual species responses and chance.
5. What does climax pattern theory emphasize?Answer: Community composition varies with species responses to the total environment.