Ecology- Day 2- Interactions

1. Ecology- Day 2- Interactions Biology- Miss Schwippert

2. II. General Information • There are 5 types of biotic interactions in most ecosystems • The more relationships there are in an ecosystem, the more stable the system tends to be • If an ecosystem has many links in it, then altering one link has a lower effect on the rest of the system.

3. III. Commensalism • An interaction where one organism benefits and the other is neither benefited or harmed.

4. IV. Mutualism • An interaction where both organisms benefit and neither are harmed.

5. Ecological Succession • Ecosystems are constantly changing in response to natural and human disturbances • Ecological Succession- A series of predictable changes that occur in a community over time • Primary succession- no soil exists- primary species (1st species to populate new area • Secondary succession- land that was cleared or plowed for farming is abandoned

6. V. Parasitism • Parasitism is a special type of predation. • Parasites use another organism for energy but usually the organism does not die, they are weakened or injured. • In this relationship, the parasite benefits and the other organism is harmed.

8. Habitat vs. Niche • Habitat- the area where an organism lives • Includes both biotic and abiotic factors • Niche- the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions

9. VI. Competition • An interaction where two or more organisms must use the same food, space, mates, or another resource to survive. • Competition- occurs when organisms of the same or different species attempt to use an ecological resource in the same place at the same time • Competitive exclusion principle- no two species can occupy the same niche in the same habitat at the same time

10. https://www.youtube.com/watch?v=E5nfVsZcjDc

11. VII. Predation http://www.battleatkruger.org/ • Predation is the act of one organism killing and consuming another for its nutrients. • Predator/Prey relationships are rarely static, they tend to fluctuate.

12. D. Because the predator-prey relationship is so complex, most predators will actually have several prey items to choose from. E. Why?