Community Dynamics and Ecological Succession

Vocabulary flashcards covering community dynamics, ecological succession, heterotrophic decomposition, and fire adaptations from Chapter 18.

Allogenic factors

Physical environmental factors, such as water availability and pH, that are caused by external forces or conditions outside the biological community.

Autogenic change

Environmental changes brought about from within by the community itself as organisms alter their own physical environment.

Ecological succession

An orderly replacement of one biological community with another driven by changing physical conditions and immigration from surrounding communities.

Climax stage

A relatively stable equilibrium stage reached by a community and its physical environment, which persists until a major ecological disturbance occurs.

Phloem

The nutrient-rich layer of tree bark between the wood and outer bark (periderm) that carries sugars and is invaded first during log decomposition.

Brown-rot fungi

Decomposing fungi involved in wood succession that specifically break down cellulose.

White-rot fungi

Decomposing fungi involved in wood succession that produce a battery of enzymes to break down lignin.

Lignin

An organic compound that binds plant cell walls together, occurring in higher concentrations in woody plants than in herbaceous plants.

Intermediate successional stage

The transitional stage of succession that exhibits the highest species diversity because species from overlapping growth stages co-occur.

Serotinous cones

Seed cones that remain sealed shut and require exposure to the heat of a fire to open and release their seeds.

Soil seed bank

A collection of dormant seeds stored in the soil for years or decades, waiting for proper conditions (such as fire) to trigger germination.

Endemic species

A unique species natively restricted to a single, specific geographic area.

Kirtland's warbler (Setophaga kirtlandii)

An endangered bird species endemic to Michigan that is fire-dependent because it nests exclusively in young stands of Jack pine.

Jack pine (Pinus banksiana)

A fire-adapted pine tree species featuring fire-resistant bark and serotinous cones, providing essential nesting habitat for Kirtland's warbler.

Longleaf pine (Pinus palustris)

A pine species adapted to fire through a grass-stage growth habit, initiating rapid stem elongation only after fire clears surrounding competition.

Fireweed (Chamaenerion angustifolium)

An herbaceous plant species that relies on persistent soil seed banks to germinate and establish rapidly following a fire.

Prescribed burn

A controlled fire set intentionally (often in springtime) as a management tool to restart succession, clear competitors, and preserve fire-dependent habitats.