1. Communities

2. Communities Community: Different populations that live together in the same area. Includes an animals niche and/or habitat

3. Habitat vs. Niche Habitat = all aspects of the area in which an organism lives. biotic factors abiotic factors Niche = niche includes all of the factors that a species needs to survive, stay healthy, and reproduce. food abiotic conditions Behavior

4. Communities The types of interactions that occur within a community, both between and within populations, can powerfully affect an ecosystem.

5. Community Interactions 3 Types of Interactions: 1.Competition 2.Predation 3.Symbiosis

6. Community Interactions - Competition Competition: When organisms of the same or different species attempt to use the same ecological resource in the same place at the same time In nature, competition usually results in a winner (who survives) and a loser (who dies)

7. Community Interactions - Competition Competitive exclusion keeps two species from occupying the same niche. One species is better suited to the niche and the other will either be pushed out or become extinct. The niche will be divided. The two species will further diverge.

8. Community Interactions - Competition Intraspecific Competition between the same species Ex. Tigers over food Interspecific: Competition between 2 or more different species Ex. Hyenas and Lions

9. Community Interactions - Predation Predation: When one organism captures and feed on another organism. The predator eats the prey

10. Community Interactions - Symbiosis Symbiosis = Any relationship in which two species live closely together. The term literally means “living together”

11. Community Interactions - Symbiosis What are the 4 main types of symbiotic relationships? 1.Mutualism 2.Commensalism 3.Amensalism 4.Parasitism

12. Community Interactions - Symbiosis Mutualism = both species benefit. +/+

13. Commensalism = one member benefits, but the other is neither harmed nor helped +/o Human Our eyelashes are home to tiny mites that feast on oil secretions and dead skin. Without harming us, up to 20 mites may be living in one eyelash follicle. Demodicids Eyelash mites find all they need to survive in the tiny follicles of eyelashes. Magnified here 225 times, these creatures measure 0.4 mm in length and can be seen only with a microscope. + Organism benefits + Ø Ø Organism is not affected Commensalism

14. Community Interactions - Symbiosis Amensalism = one species impedes or restricts the success of the other, but remains unaffected -/o algal blooms can lead to the death of many species of fish, however the algae do not benefit from the deaths of these individuals.

15. Community Interactions - Symbiosis Parasitism = one organism lives on or inside another organism and harms it +/- Organism benefits 0 _ Organism is not affected Hornworm caterpillar The host hornworm will eventually die as its organs are consumed by wasp larvae. Braconid wasp Braconid larvae feed on their host and release themselves shortly before reaching the pupae stage of development. _ Parasitism + 0