1. LG: How Do Ecosystems Recover from a Disturbance?
January 2013 Regents food web question

2. ECOLOGICAL SUCCESSION It can occur on LAND or in AQUATIC ecosystems.
is the series of changes that occur in an ecosystem over time.
It can occur on LAND or in AQUATIC ecosystems.
Steps and stages to achieve in order to achieve success in something.

3. There are TWO types of succession on LAND.
1. PRIMARY
2. SECONDARY

4. Primary succession occurs on BARE ROCK.
is the sequence of communities that form in an originally lifeless habitat.
Primary succession occurs on BARE ROCK.
READ THE 1ST PARAGRAPH IN PRIMARY SUCCESSION> p. 92
Primary Succession is the sequence of communities that form in an originally lifeless habitat. Primary Succession os an orderly and predictable process. It follows the same general pattern in most ecosystems.
Primary succession occurs on bare rock – newly exposed surfaces such as volcanic rock and ash. Oceanic volcanoes create islands when they erupt. Volcanic eruptions destroy the previous ecosystem that existed by covering it with lava that cools and turns into rock.
The first organisms to appear are LICHENS. Lichens are fungus and algae living in a mutualistsic relationship. lichens can live on bare rock. Why couldn’t plants live on bare rock?
Lichens secrete acids that break down the rock and form organic material by photosynthesis. Rocks are also broken down by weathers from wind and water. Lichens and weathering break down the rock and form a thin layer of soil of time.
The lichen community is called a pioneer community.

5. What could occur to give us bare rock in a place that had already had plants living?

6. The first organisms (pioneer organism) to appear are LICHENS.
Primary Succession
The first organisms (pioneer organism) to appear are LICHENS.
Lichen is a FUNGUS and ALGAE living in a MUTUALISTIC relationship.
Lichens grow on bare rock and break down the rock.
When the lichens die they form a thin layer of soil.

7. The first living things to grow successfully on a newly formed sand dune are known as a. saprophytes b. pioneer organisms c. carnivorous plants d. heterotrophs

8. Lichens grow on bare rock and break down (weather) the rock to form a thin layer of soil.

9. The lichen make up a PIONEER COMMUNITY.
Primary Succession
The lichen make up a PIONEER COMMUNITY.
A pioneer community is the first one in a new habitat.

10. Base your answer on the diagram below, which shows the sequence of plant communities that have occupied land that was left barren 300 years ago, and on your knowledge of biology.
Which plant species represent pioneer organisms?
a. broomsedge and pine seedlings
b. ragweed and aster
c. crabgrass and horseweed
d. oak and hickory trees

11. Lichens & Mosses

12. Crevice Community

13. 2.Lichens & mosses (pioneer)
THE STAGES OF PRIMARY SUCCESSION
1.Bare rock
2.Lichens & mosses (pioneer)
3.Grasses and shrubs
4.Trees (climax community)

14. Base your answer on the diagrams below of four stages of a biological process and on your knowledge of biology What would most likely be the predominant life form found in stage I? a. ferns b. tracheophytes c. mushrooms d. pioneer species

15. A Typical New York State Succession

16. A slab of bare rock is covered with lichens
A slab of bare rock is covered with lichens. In time, mosses cover the rock, followed by grasses, and finally by small shrubs and tree saplings. In this example, the lichens represent a. a climax community b. a dominant species c. secondary consumers d. pioneer organisms

17. A CLIMAX COMMUNITY
is a diverse and mature community that does not go through more succession.
should be able to withstand disruption better than earlier ecosystems, causing succession to stop
Climax communities are often highly diverse and can survive even severe disturbances. Climax communities are MATURE ECOSYSTEMS that will change very little over time.

18. ECOSYSTEM STABILITY
During succession, the stability of an ecosystem changes
Stability is the ability of an ecosystem to remain constant in the face of disturbance

19. Which organism is one of the first autotrophs to appear in this succession? a. frog b. aquatic plant c. tree d. fish

20. As the diversity of an ecosystem increases, the stability increases
A more diverse ecosystem contains a more complex food web
This means an organism is more likely to find an alternate food source if need be.

21. Changes in an ecosystem over a long period of time are shown in the diagram below These changes will most likely lead to a a. stable ecosystem that can last for many years b. loss of heterotrophs that cannot be recovered c. long-term rise in environmental temperatures d. forest consisting of only producers and decomposers

22. Base your answer on the diagram below, which shows the sequence of plant communities that have occupied land that was left barren 300 years ago, and on your knowledge of biology Dominant plant species in the climax community include a. pine trees b. hickory trees c. mosses d. lichens

24. www.educeth.ch/stromboli/ perm/msh/life-en.html
The great eruption of Mount St. Helens on 18. May 1980 is one of the best documented cataclysmic eruptions in historic times.
Life returns ( )
In July 2001 we visited Mount St. Helens for the second time and tried to locate as many places as possible where we had taken photos previously in Due to the rapid growth of vegetation this was sometimes more difficult than we had anticipated. Using triangulation techniques for a first, rough localisation and then the position of individual stones or logs to finally pinpoint the precise location of the camera. perm/msh/life-en.html
perm/msh/life-en.html

27. The diagram below shows various ecological communities that occupied an area over a period of 300 years Which statement best describes the diagram? a. Community A is the most stable community. b. Community B replaced community C after a period of 100 years. c. Community C developed into community A after a period of 75 years. d. Community D modified the environment, making it more suitable for community E

28. SECONDARY SUCCESSION
occurs where an existing community has been cleared by some disturbance but the soil is not destroyed.
Secondary succession often occurs after human disturbance. (abandoned farm field, vacant lots in urban areas even)
Fire may kill many plants but leave the soil in place. living organisms quickly re-colonize the soil after a fire. There are certain trees that need fire inorder to release their seeds. PINE BUSH. Pitch and jack pine.

29. Secondary Succession
DEFORESTATION and FIRE are disturbances that will clear the existing community but not destroy the soil.

30. Secondary Succession

32. Over a long period of time, the stages represented in the diagram below were each present in a particular ecosystem After a forest fire, what is the most likely order in which these stages appeared? a. D C A B b. B D C A c. A B C D d. B C D A

33. Aquatic HABITATS are in WATER.
Aquatic Succession
Aquatic HABITATS are in WATER.
Over long periods of time ponds fill in slowly with sediments and plants.

35. Aquatic Succession

37. The ponds fill in over time to become a marsh, a meadow or eventually a forest.

38. Which statement best describes one of the stages represented in the diagram below? a. The mature forest will most likely be stable over a long period of time. b. If all the weeds and grasses are destroyed, the number of carnivores will increase. c. As the population of the shrubs increases, it will be held in check by the mature forest community. d. The young forest community will invade and take over the mature forest community.