Ecological Succession

1. Ecological Succession Mr. Lux Earth and Environmental Science

2. Objectives • The students will be able to define primary and secondary succession. • The students will be able to compare and contrast primary and secondary succession. • The students will be able to identify the progressive steps which occur during the succession process.

3. The Life Cycle of a Forest Succession is an integral part of the balance in an ecosystem. This dynamic change in the environment is due to many variables. In the end, it can be looked upon as one of the many life cycles present in the environment.

4. Succession is an ecological term for the orderly and progressive replacement of one community by another until a relatively stable community occupies a particular area. This area could be a small woodlot, the side of a volcanic mountain, or even an overturned stone in a stream.

5. Primary succession can be defined as succession that occurs on areas which are devoid or unchanged by organisms. Secondary succession can be defined as succession that occurs on areas where organisms are already inhabiting and are present. Two Types of Succession

6. Primary Succession • A primary succession occurs on substrate which is free from all organisms and can be viewed as: “MOTHER NATURE’S CLEAN SLATE”

7. Newly exposed rocks and cliffs. Rocks and boulders in a stream bed or tidal area. Sand dunes produced from major beach erosion (as in a hurricane). Ecological Clean Slates

8. When a newly exposed substrate is introduced into the environment, colonizing species attach themselves and begin to grow and develop. An example of this would be a type of moss or fungi.

9. The new colony inhabits the substrate until another more complex organism overtakes it and the process continues until the substrate is disturbed and the “SLATE” is incidentally “cleaned”. This type of succession usually occurs very rapidly and the colonies usually do not get a long time to develop the substrate.

10. Primary succession occurred on all continents during the beginning of Earth’s history. Each organism which came to live on dry land had to participate in the succession process.

11. Question #1 What type of substrate does primary succession occur on? • A forest • A rock in a streambed • The middle of the interstate

12. Sorry, Please Try Again… The forest floor is a major component of secondary succession. It, however, already has organisms which inhabit it.

13. YES, Good Job!!! Yep, a rock in a streambed is constantly getting disturbed and this allows for primary succession to take place.

14. Sorry, Please Try Again… You might want to review the last couple of slides before you try and answer the question again…

15. Secondary Succession A secondary succession occurs on substrate which has been or is presently occupied by organisms and the substrate is capable of harboring some form of life.

16. The cycle which occurs in a temperate forest and most biomes is one in which the complexity and development of the inhabitants increases until a climax community is reached. Stable climax community  Large shrubs and trees  Small shrubs and grasses  Mosses and lichens  Recently disturbed area of land Steps of Development

17. The stable climax community will continue to grow and proceed until an event alters the state of the community. Examples of events could be: • A forest fire • A major flood or volcano • The clear cutting of a forest for farm use

18. Early stages of secondary succession are characterized by: • Few species • Low source of nutrients • Short food chains • Low biomass

19. Late stages of secondary succession are characterized by: • High diversity • Large amount of nutrients • High biomass • Large, complex food chains

20. Cleaning the Slate • Forest fires are an important event in the life cycle of a forest. They allow the forest to be revived and reborn, cleaning off the slate, so to speak. This is a healthy occurrence for the forest and allows the cycle of succession to restart and begin again. Without them a forest would reach the climax stage and remain there for a tremendous amount of time.

21. Question #2 What stage of succession is characterized by low biomass and a low number of species? • The Early Stages • The Middle Ages • The Late Stages

22. Outstanding Work!!! Yes, the early stages of secondary succession are indicated by these types of characteristics.

23. Sorry, Please Try Again… Sorry, the Middle Ages were not discussed in this tutorial. The knights probably did witness succession in their forests, though.

24. Sorry, Please Try Again… The late stages of secondary succession are indicated by the large amount of diversity and large amount of biomass present in the particular area.

25. Question #3 A forest fire is beneficial to the forest in what way? • It allows the forest to die forever. • It allows the forest to be reborn and replenishes the soil with nutrients. • It allows the animals to roast marshmallows by the fire.

26. Sorry, Please Try Again… No, the forest is not gone forever, if it was, there wouldn’t be that much forest left in the world.

27. Sorry, Please Try Again… No, the animals would not hang around if a forest fire was in the area. They can sense immediate danger and would either evacuate or perish in the fire. By the way, how would the animals get the money to buy the marshmallows???

28. Great Job, Keep up the Good Work!!! Congrats!! You have successfully completed this tutorial on the section on primary and secondary succession. Try and remember all that you have learned, it will be important one day…