1. Changes in Ecosystems: . Ecological Succession

2. Do all ecosystems stay the same all the time?
What are some things that cause changes to ecosystems?
Natural and unnatural (Quickly and slowly)

3. Ecological succession
Natural, gradual changes in the types of species that live in an area; can be primary or secondary
The gradual replacement of one plant community by another through natural processes over time

4. Ecological succession
Series of predictable changes that occur in a community over time. Caused by:
Physical environment
Natural disturbance
Human disturbance

5. Primary Succession Begins in a place without any soil
Sides of volcanoes
Landslides
Glacier melting
Starts with the arrival of living things such as lichens that do not need soil to survive, called PIONEER SPECIES.

8. Pioneer species
Lichens

10. Primary Succession
Pioneer species: Lichens, don’t need soil to grow
They die and adding organic material.
Simple plants like mosses and ferns can grow in the new soil
The simple plants die, adding more organic material
The soil layer thickens, and grasses, wildflowers and other plants begin take over.
This plant die and add more nutrients to the soil
Shrubs and trees can survive now
Insects, small birds, and mammals have begun to move in
What was once bare rock now supports a variety of life

11. Reaching a mature community can take CENTURIES.

12. Secondary Succession
Begins in an area where the ecosystem has been disturbed, but where soil and organisms still exist.
Occurs faster and has different pioneer species than primary succession

13. Succession following a disturbance that destroys a community without destroying the soil
Fires Forest clearing Natural Human disturbance
Hurricane - Farming

18. Secondary succession
Unlike primary succession, secondary succession occurs in a place where and ecosystem currently exists.
And occurs more rapidly than primary succession.

21. Climax Community
A stable group of plants and animals that is the end result of the succession process
Does not always mean big trees
Grasses in prairies
Cacti in deserts

22. Think-Pair-Share Shoulder Partners
PAGE
PRIMARY SUCCESSION
SECONDARY SUCCESSION

23. References:
Science explorer Prentice Hall. Environmental Science

24. Succession in Marine Ecosystems
Deep and dark
Can succession happen?
1987 dead whale off of California
Unique community of organisms living in remains
Represents stage in succession in an otherwise stable, deep-sea ecosystem
Whale-fall community

26. Whale-Fall Succession
Begins when large whale dies
Sinks to barren ocean floor
Scavengers and decomposers flock to carcass , our first community
Amphipods
Hagfish
sharks
After a year, most tissues have been eaten
Now, second small community of organisms live here
Body is decomposing, releasing nutrients into the water
Small fishes
Crabs
Snails
worms
Only skeleton remains…
Third community moves in
Heterotrophic bacteria
Decompose oil in bones release of chemical compounds
Who uses these chemical compounds?
Chemoosynthetic autotrophs
In come the crabs, clams, and worms that feed on this bacteria