1. Notes: Ecosystem Structure

2. Objectives
Explain how biotic and abiotic factors influence an ecosystem
Identify the interactions that occur within communities
Describe how ecosystems recover from a disturbance

3. biotic
Living factors of an environment

4. abiotic
The non-living factors of an environment
Ex.) water, soil, air

5. Biotic and Abiotic
Together, biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives

6. Habitat
Where an organism lives

7. Squirrel in tree

8. Fish in stream

9. Niche The role an organisms plays in its environment
A niche is what the organism eats, what organisms eat it, what interactions in has with other organisms and its environment.
No two species can share the same niche in the same habitat

11. Community Interactions
Community interactions, such as competition, predation, and various forms of symbiosis, can powerfully affect an ecosystem.

12. Competition
Competition occurs when organisms of the same or different species attempt to use an ecological resource in the same place at the same time
Direct competition in nature often results in a winner and a loser—with the losing organism failing to survive

13. Competitive exclusion principle
States that no two species can occupy the same niche in the same habitat at the same time

14. Predation When one organism captures and feeds on another organism
The organism that does the killing and eating is called the Predator, and the food organism is the Prey.

15. Symbiosis Any relationship in which two species live closely together
Biologists recognize three main classes of symbiotic relationships in nature

16. Mutualism When both members benefit
Examples: Cats and Humans or Dogs and Humans

17. Lichens: close association between
algae and fungi

18. Ant – Acacia Tree

19. Commensalism
When one member benefits and the other is neither helped nor harmed
Example: birds nesting in trees

20. Clownfish – Sea Anemone

22. Parasitism When one member benefits and the other is harmed
Show Body Invader Video

23. Humans - Tapeworms

24. Ecological Succession
Ecosystems are constantly changing in response to natural and human disturbances. As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the community.
The series of predictable changes that occurs in a community over time

25. Primary Succession
Succession that occurs on new land where no soil exists
Ex.) volcanic islands, bare exposed rock when glaciers melt

26. Pioneer species The first species to populate an area
Ex.) lichen, algae, mosses

28. Secondary Succession
When a disturbed area grows back to normal. For example
natural disaster areas (Fire on Mt. Lemmon)

29. Closure Share with your partner !!!
In your own words, summarize what you learned about each of the following:
Biotic and abiotic factors in ecosystems
Habitat and Niche
Competitive Exclusion Principle
Types of community interactions
Primary and secondary succession
Share with your partner !!!