Lecture 24: Community Ecology

CC types of interactions

What is competition in ecology?

When two or more species compete for the same limited resources, such as food, water or space.

What is the outcome of competition?

Both species are negatively impacted because they are fighting for limited resources.

Example of competition

Lions and hyenas competing for the same prey.

What is predation?

When one organism kills and consumes another

Example of predation

A wolf hunting a dear.

What is symbiosis?

A close and long-term interaction between two different species

What are the possible outcomes of symbiosis?

Outcomes vary depending on the type: mutualism, commensalism, or parasitism

What is parasitism?

A symbiotic relationship where the parasite benefit and the host is harmed (rarely killed)

What is the interaction sign for parasitism?

+/- (one benefits, one is harmed)

Example of parasitism

A tick feeding on a dogs blood, where the tick benefits and the dog loses blood.

What is mutualism?

A symbiotic relationship where both species benefits, often depending on each other.

What is the interaction sign for mutualism?

+/+ (both benefit)

Example of mutualism

Bees pollinating flowers, bees gets nectar and flowers are pollinated to reproduce.

What is commensalism?

A symbiotic relationship where one species benefits and the other is unaffected.

What is the interaction sign for commensalism?

+/0 (one benefits, one is neutral)

Example of commensalism

Barnacles attaching to a whale for housing and food access while the whale is not affected.