Succession A process of ecological change in which a series of natural communities are established and then replaced over time is called_______________________ Succession

Succession that takes place on an area that was originally completely empty of life is called___________________ Primary Succession

Succession Succession that occurs in an area where an ecosystem exists but has been disturbed is called _________________ Secondary Succession

Succession Plants or communities that are the first to be established in an area previously empty of life are called _______________ Pioneer Species

Succession Plants with short life spans that devote most of their energy to producing seeds are called _________________________ Opportunistic Species

Succession A relatively stable community that is environmentally balanced is called a ________________. Climax community

Succession Most of the entire eastern US has been clear cut for agricultural use and timber. Today only a fraction of the original old growth forest remains.

Succession What are the most common pioneer plant species in primary succession? – mosses and lichens that grow on rock.

Succession What are the most common pioneer plant species in secondary succession? – annual weeds such as crabgrass

Succession Why are the pioneer species in primary and secondary succession different? – Because in secondary succession there is already soil present. Therefore lichens and moss are not necessary.

Pioneer species quickly occupy a site following clearing. They grow rapidly to compete with grasses and shrubs.

As the crowns of pioneer species close, seedlings from these trees are unable to survive in the resulting shade.

Different species that have a higher tolerance to shade soon become established beneath the pioneers.

As the short-lived pioneers near the end of their life spans, the more tolerant trees in the forest understory begin to take over the site. The result is a major change in plant and animal species.

Beneath the second successional stage species, that often form thicker crowns than pioneers, new species that are even more shade tolerant become established.

The process of succession continues until the most shade-tolerant species suitable for the site (climax species) become established.

Seedlings of highly shade tolerant climax species thrive in the shade of their parents. Because of this, climax species will persist until disturbance sets back the succession process to the pioneer or some other stage.

Forest Succession Takes place over hundreds of years. Species of climax forest will vary with geographic location – Beech Maple – Oak Hickory

NJ Pine Barrens Deviates from the typical pattern of eastern deciduous forest succession. Example of “fire disclimax.

NJ Pine Barrens