2.7: Ecological Succession

Vocabulary flashcards covering key terms and definitions related to ecological succession, including primary vs secondary succession, pioneer and mid/late-successional species, and soil development processes.

Ecological Succession

A series of predictable stages of growth that a forest goes through.

Primary Succession

Succession starting from bare rock with no prior soil formation; moss and lichen colonize rocks and weather them to form soil.

Secondary Succession

Succession starting from established soil after a disturbance; grasses, sedges, wildflowers, and berry bushes recolonize via wind or animal-dispersed seeds.

Pioneer species

First species to appear in early succession; wind-dispersed, fast-growing, sun-tolerant (examples include moss/lichen on bare rock).

Mid-successional species

Species that appear after pioneers, helping develop deeper, nutrient-rich soil through growth and death cycles (examples: wildflowers, grasses, sedges, raspberries; moss/lichen on bare rock earlier).

Late successional / climax community

Species that appear last as soils deepen; examples: maples, oaks, large trees; tolerant of shade.

Stage characteristics (pioneer)

Seeds spread by wind or animals; fast-growing; tolerant of shallow soil and full sunlight; examples: shrubs, bushes, fast-growing trees like aspen, cherry, pine.

Stage characteristics (mid-successional)

Relatively fast-growing, larger plants that require deeper soils with more nutrients; sun-tolerant.

Stage characteristics (late/climax)

Large, slow-growing trees tolerant of shade; require deep soils for large root networks.

Bare rock

Area with no soil, the starting substrate for primary succession.

Moss and lichen

Pioneer organisms that disperse spores by wind; secrete acids to weather rock and release minerals; contribute to initial soil formation.

Chemical weathering

Weathering of rocks by acids from moss/lichen and organic matter from their decay; forms initial shallow soil (N, P, K).

Volcanic rock

A substrate example for primary succession (bare rock on lava-derived surfaces).

Rock exposed after glacial retreat

Bare rock substrate for primary succession; exposure after ice melt allows colonization.

Ash from fire

Nutrient-rich ash that enriches soil and speeds secondary succession.

Disturbance

Event (fire, tornado, human land clearing) that clears most plant life and triggers secondary succession.

Seeds dispersed by wind or animals

Means by which pioneer and many secondary-succession plants spread and recolonize.

Soil depth and nutrient availability

Key factors that determine which plant species dominate at each successional stage.