How Ecosystems Change Primary Succession occurs on a surface where no ecosystem existed before...

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Transcript of How Ecosystems Change Primary Succession occurs on a surface where no ecosystem existed before...

How Ecosystems Change• Primary Succession occurs

on a surface where no ecosystem existed before

• Secondary Succession occurs where an ecosystem previously existed—pioneer species, climax community

View 33 slides on Internet

• http://www.authorstream.com/Presentation/ranirajendran-1483170-ecological-succession/

Primary Succession

Ecological Succession

Secondary Succession

• Mt St. Helen’s June 17, 1984

Secondary Succession

• Mt. St. Helen’s August 20, 2013

Pioneer and Niche Species

Pioneer species are generally small hardy species that spread into un-colonized areas.

They are often perennial species that spread quickly, die off each season and leave behind a large amount of seeds for the next season.

Niche species are larger more complex organisms that live longer and interact with the surrounding environment more.

Niche species fill a biological gap where their specific traits suit their needs for survival without infringing on other species needs.

Climax Communities

• When a barren area has been sufficiently occupied and prepared by pioneer species, the landscape develops into a climax community

• Succession continues to very the biotic landscape as organisms co-evolve and adapt to the equalized state.

Old Field Succession