PoE Exam 4

Succession

Gradual change in plant and animal communities in an area following disturbance or the creation of new substrate

Pioneer community

The first community, in successional sequence, to establish following a disturbance

Climax community

A community that occurs late in succession, whose population remains stable until disrupted by disturbance

Primary succession

Succession on newly exposed geological substrate that’s not significantly modified by organisms

Secondary succession

Succession where disturbance has destroyed a community but not the soil

What’s the difference between primary and secondary succession?

• Primary succession: Succession begins on ground zero

• Secondary succession: Succession begins on a disturbed, preexisting community

How do communities change during the succession process?

Increase in species diversity and changes in species composition

Facilitation model

Pioneer species modify the environment to support suitable species at later successional stages instead of themselves

Tolerance model

Climax species are present in early stages, they’re just tolerant of early environmental conditions

Inhibition model

Early occupants modify the environment to make it less suitable for early and late successional species

Stability

Persistence of community or ecosystem in the face of disturbance

Resistance

Capacity of a community or ecosystem to maintain structure/function in the face of disturbance

Resilience

Capacity to recover structure and function after disturbance

A hurricane hits a forest in the Texas Gulf Coast and destroys the forest. What succession happens next?

Secondary

Through the primary process of succession, what would increase?

Available nitrogen and species diversity