Ecological Succession

Ecological Succession Series of changes that occur in a community

over time.

So why do communities change over time?Because of Disturbances in the

community

Disturbances can be:Fires, Volcanic Eruptions, Floods,

Landslides, Mining , Deforestation etc…

Two Types of Ecological Succession1. Primary

Succession that begins in an area with no remnants of a previous community (Barren land; no evidence of life)

Typically happens after volcanic eruptions or retreating glaciers

2. Secondary Begins in communities where life was not

completely destroyed Typically happens after floods, forest fires, ,

mining etc.

Primary Succession

Secondary Succession

Pioneer Species- First species to colonize barren areas Occurs only for primary succession Example: Lichen

Climax Community Stable community with a diverse number

of species (End result of ecological succession)

Healthy ecosystems can return to its original climax community

Plants Pioneer/Soil Building

Plants Lichen

Grasses/Weeds (fast growing)

Shrubs Fast growing/ Sun

Tolerant Trees Aspens

Slow Growing/ Shade Tolerant Trees Evergreens, Pines, Oak

etc..

Animals None at first Very small herbivores

Insects, birds, rodents Larger Herbivores and

Small carnivores Rabbits, squirrels, foxes

Largest Herbivores and Carnivores Elk, Deer, Wolves,

Coyotes, Bears

FIRST

LAST

Are all disturbances bad for an ecosystem?

NO, sometimes ecosystem are unhealthy. Succession can help restore health and biodiversity to an area.