Transcript Primary Succession

Ecological
Succession
the beginning of the biotic
environment
Stable Ecosystem
• Little or no change takes place
• Examples:
– Deserts, forests, grasslands.
Primary Succession
• New life where no life
previously exists.
Steps of primary succession
pg 377
1. Rocks no life
2. Pioneer species – first organisms to live
in an area. (usually lichens) soil is made
3. Small simple organisms replace lichens.
4. Soil thickens and more complex
organisms begin to grow.
5. Hundreds of years later, tree’s can exist
Secondary Succession
pg. 378
•
Re-growth
•
Communities need to be in balance.
Some are disturbed by natural events
and human activities.
Steps of secondary succession
• An event kills an area of growth.
• Small seeds from surrounding life are
planted in the newly destroyed area.
• Organisms that feed on the new growth
begin to move in carrying more complex
seeds.
• As more complex organisms die, others
may take their place.