What is a community?

1. What is a community? The study of more than one species living in a particular area (ecosystem)

2. Types of interactions • Competition (interspecific and intraspecific) • Predation • Symbiosis (mutualism, commensalism, and parasitism)

3. Competition (interspecific) • Two or more different species competing for the same resource. This means that the two species have the same niche • Niche- role or job in the environment

4. Competition (intraspecific) • Fits more under the population level • Organisms of the same species are competing for the same resource

5. Predation • One organism hunts, kills, and consumes the other organism • The hunter is the predator • The hunted is the prey • Also called a predator/prey relationship

6. Symbiosis • Close relationship between two or more different species • Believed to have evolved together

7. Symbiosis (mutualism) • Both species benefit from the relationship

8. Symbiosis (commensalism) • One species benefits and the other is not harmed nor benefits

9. Symbiosis (parasitism) • One species benefits (parasite) and the other is harmed (host) but is *usually not killed • Endoparasitism- internal parasite • Ectoparasitism – external parasite • Brood parasitism- one organism (parasite) uses another organism(host) to raise young harming the young of the host species

10. Pictures of parasitism

11. Brood parasitism pictures

12. Succession • Gradual and sequential replacement or addition of communities over a period of time.

13. Primary succession • Succession where there has never been life • Lava rock forming new land • Glaciers exposing land never occupied before

14. Secondary succession • Succession on land that has been occupied before but something wipes out the original community. • Sometimes the same species come back. Sometimes new species occupy the area. • Logging • Volcanic eruption (Mt. St. Helens) • flood

15. Secondary succession pictures