1. Ecology Chapters 34-38

2. What is ecology?  Study of how organisms interact with each other and their physical environment  Greek origin “oikos”  meaning house

3. Key Terms  Biosphere – part of planet in which all life exists (includes water, land, air)  Ecosystem – most complex system a biologist studies  Consists of a community and a habitat  Community – populations of different species that live in one area  Ex: animals, plants, fungi, etc. in a forest  Habitat – physical location where a community lives  Ex: soil and water that make up a forest

4. Different factors that shape ecosystems…  Biotic factors – living influences on ecosystems  Interactions with birds, trees, mushrooms, etc.  Abiotic factors – non-living influences on ecosystems  Temperature, precipitation, wind, humidity

5. Energy Flow  Food Chains  Shows simplest feeding relationships between organisms  Grass  mouse  snake  hawk

6. Energy Flow, cont’d.  Food Webs  Complex diagram showing how ALL organisms are connected in a habitat

7. Trophic Levels  Number of steps away from the sun in food chains/webs  Level 1 = Plants/producers  Level 2 = Primary consumer/herbivore  Level 3 = Secondary Consumer/ carnivore  Level 4 = Tertiary Consumer/ top carnivore

8. Trophic Level Example Level 1 Level 2 Level 3 Level 4 Level 5