ECOLOGY- DAY 2- INTERACTIONSBiology- Miss Schwippert

II. General InformationA. There are 5 types of biotic interactions

in most ecosystemsB. The more relationships there are in an

ecosystem, the more stable the system tends to be

C. If an ecosystem has many links in it, then altering one link has a lower effect on the rest of the system.

III. Commensalism

A. An interaction where one organism benefits and the other is neither benefited or harmed.

IV. MutualismA. An interaction where both organisms

benefit and neither are harmed.

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

V. ParasitismA. Parasitism is a special type of

predation.B. Parasites use another organism for

energy but usually the organism does not die, they are weakened or injured.

C. In this relationship, the parasite benefits and the other organism is harmed.

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

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

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

VII. Predation

A. Predation is the act of one organism killing and consuming another for its nutrients.

B. Predator/Prey relationships are rarely static, they tend to fluctuate.

http://www.battleatkruger.org/

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

E. Why?