Succession Flashcards

Flashcards on Succession

Succession

Cumulative change in plant species composition over time

Sere

A 'unit' (episode) of succession

Pioneer community

Initial community of a sere (succession)

Seral community

Any community undergoing succession; a stage of succession

Climax

Final stage of some seres when composition changes are non-directional, random, & usually minor

Disturbance

Any event that severely damages/destroys vegetation & initiates a sere

Primary succession

Substrate (lava, glacial till, etc.) not previously vegetated

Hydrarch

Wet sites, ponds, lakes

Xerarch

Dry substrate: bare rock, sand, etc.

Secondary succession

Previously vegetated areas

Autogenic Succession

Changes caused by organisms in the community

Allogenic Succession

Vegetation Change caused by short-term changes in environmental conditions

Progressive Succession

From more extreme (wet, dry, exposed) to more mesic conditions; Communities become progressively more complex

Retrogressive Succession

Toward conditions that are less mesic, more extreme; Trend to simpler, less complex/ diverse communities

Directional Succession

Diverges from initial state

Cyclic Succession

Cycles back to initial state

Community Types on the Landscape

Plant Associations occur in a patchwork across the landscape

Chronosequence

Series of community types resulting from different succession stages

Toposequence

Series of vegetation types resulting from differences in soils, drainage, topography, parent material, etc.

Climatic climax

One possible climax for a region

Edphatic climax

Local climax determined by soil properties

Topographic climax

Local climax determined by topography, slope aspect, etc.

Subclimax (disclimax)

Recurring, non-catastrophic disturbance drives community away from climatic climax to another stable type

Relay floristics

Each seral community prepares the site & facilitates the next

Initial floristic composition

Progression of seral communities not predictable but depends on initial propagules present

Inhibition

Early stages slow or inhibit later stages

Tolerance

Many species may be present initially but later-stage species are better competitors & will eventually win