Transcript Primary Succession - Effingham County Schools

Succession
• Ecosystems are NOT static, they are constantly
changing
– Natural forces and human activity disturb them
• Ecological succession - series of changes that
occur over time in an ecosystem
• Organisms occupy a site & change the environment
so that other organisms can come in
• Two Types:
– Primary succession
– Secondary succession
Primary Succession
• Primary succession - happens on
surfaces where no soil exists (lifeless
ground).
• Examples
– after a volcanic eruption
– after a glacier melts
Primary Succession Steps
1. Pioneer species arrive (lichens): don’t need soil
to survive
2. Lichens die & decompose  organic matter
mixes with rock to start making soil
3. Mosses & ferns can grow in new soil  die &
add more nutrients to soil
4. Grasses & wildflowers can move in  die & add
more nutrients to soil
5. Shrubs & trees can survive
6. End in Climax community
Pioneer species
• First set of species to
establish themselves
• Grow rapidly
• Short lived
• Do well in bright sunlight
where nutrients are
abundant
• Seeds are widely and
rapidly disbursed
Climax Community
• lots of hardwood
• shade-loving trees
Secondary Succession
• Secondary succession – ecosystem is disturbed
but soil is not removed (previous ecosystem
remains)
• Examples
– cleared farming fields
– forest fires
– flood
– tornado
• Soil & seeds still present, so takes shorter amount of
time
• Start with grasses  herbs, shrubs, small trees 
hardwood trees (climax community)
Succession Time Line
Primary Succession
Secondary Succession
1. Start with a picture that
represents a natural
occurrence that would wipe
out top soil. EX: erosion,
glacier movement, volcanic
eruption.
2. Rocks or Earth’s crust with no
top soil.
3. Pioneer Species
4. Small shrubs/bushes
5. Pines
6. Mature hard woods
1. Start with a picture that
represents a natural
occurrence that would wipe
out top soil. Ex: fire,
mudslide, deforestation
2. Start with weeds
3. Shrubs/ bushes
4. pine
5. mature hardwoods
***Be sure to label each picture
When finished, write 2 paragraphs on your construction
paper to describe the following:
• Paragraph # 1: Primary Succession
• Explain the steps of succession.
• What traumatic events would cause this re-growth to occur?
• What are pioneering plants? What are some examples of these?
• Explain why this type of succession takes longer than secondary.
• Paragraph #2: Secondary Succession
• Explain the steps of secondary succession.
• What traumatic events would cause this re-growth to occur?
• Why would pioneer plants not be needed?
• What do secondary successions have that primary successions do
not?