1. Interdependence
Species Interactions
20.1

2. The relationship between plants, fungi, and animals that interact with one another is called INTERDEPENDENCE.
There are many different types of interdependence. In some of these relationships both organisms benefit, and in others only one organism benefits

3. Ways organisms interact with each other
Symbiosis: a relationship where at least one member benefits by the relationship
Predation (Predator/Prey) (+, -)
Mutualism (+ ,+)
Parasitism (+, -)
Commensalism (+, 0)
Competition

4. Predator/Prey
A relationship where one organism, a consumer called a predator, eats or ingests another organism, the prey. The prey in this case is also some type of consumer.
Ex– fox and rabbit

5. Producer/Consumer
A relationship where one organism, the consumer (typically an animal), eats or ingests a plant, the producer.
A type of “predator/prey”

6. Mutualism
A relationship in which two different species benefit and are dependent upon the relationship.
Ex. Ants and the acacia tree
Ants get a home & food, and the tree gets protection

7. Parasitism
A relationship between two species in which one species, the parasite, nourishes itself to the harm of the other species, the host.
Humans and tapeworms
Heartworm in dogs
Athletes foot

8. Commensalism
A relationship in which one species derives food, shelter, or protection from another species without harming that organism or providing any benefits in return.
The cattle egret benefits when the ox walks and kicks ups bugs
The ox isn’t helped or hurt by the birds

9. Competition Competition—two or more species use same limited resources
Results
Reduction of both species
Elimination of one of the competitors: Competitive Exclusion
Example
Lions and hyenas both compete for zebra