Ecology Interactions

Types of ecological interactions competition predation parasitism mutualism commensalism symbiosis

Competition – two species share a requirement for a limited resource  reduces fitness of one or both species

Predation – one species feeds on another  enhances fitness of predator but reduces fitness of prey herbivory is a form of predation

Parasitism – one species feeds on another  enhances fitness of parasite but reduces fitness of host

Mutualism – two species provide resources or services to each other  enhances fitness of both species

Commensalism – one species receives a benefit from another species  enhances fitness of one species; no effect on fitness of the other species

Symbiosis – two species live together  can include parasitism, mutualism, and commensalism

Organizing ecological interactions effect on species 1 + 0 - predation herbivory parasitism + - commensalism mutualism effect on species 2 competition

Video Elements of Biology: Ecosystems: Organisms and Their Environment http://www.pbs.org/wnet/nature/lessons/symbiotic-strategies/video-segments/1496/ Assignment: Ecological Interactions Quiz

13.2 Research Questions Name two ways in which members of the same species interact. In what ways do members of different species interact? Think of a biological community near you, and give an example of how population has affected another. Explain how symbiotic relationships are similar to and different from predator-prey interactions.