Succession: Changes Over Time

•Succession–process of gradual, natural change and species replacement that takes place in the communities of an ecosystem over time

•Two types –primary& secondary

What is Primary Succession?

•Primary Succession–takes place on land where there are no living organisms *Example- –When a volcano erupts, lava covers the entire land, killing all organisms. This type of natural event covers even the soil so there is NO LIFE AT ALL!

Primary Succession

What is Secondary Succession?

• Secondary Succession–changes that take place after an existing community is destroyed (the land still has soil though)*Example -a forest fire kills the plants but soil still exists.

Secondary Succession

What’s the difference between the two?

Organisms show up much quicker during secondary succession than primary succession because in

primary succession, there is no soil.

Pioneer Species-

• 1st species to show up

• Pioneer species are usually lichens, which are algae growing together with fungi.

• Named because they are the first to show up, like the “Pioneers” of a new place

Steps in Succession

•1st –Land is destroyed•2nd – Presence of Pioneer Species. •3rd –Slowly plant life appears. It takes less time for wild flowers and shrubs to appear than trees. Pine trees grow to maturity faster than hardwoods such as maple and oak.•4th –Animals that rely on plants slowly move in.•5th –Climax Community is established.

Climax Community

This is a stable community with a diverse number of organisms.

Now return to your seats. Use the Green text book pages 77 and 78 to

copy the pictures showing the progression of primary and secondary

succession.

Be sure to also copy the caption onto your handout under each section (A, B,

C, D) of the picture.