Principles of Ecology

1. Principles of Ecology

2. Ecology – what is it? • Scientific discipline that studies the relationships of organisms with each other and their environments. Ecologists perform experiments to understand why these relationships might occur.

3. Biotic v. Abiotic Factors • Biotic factors – living things! • Other organisms • Abiotic factors – non-living things… • Temperature • Air or water currents • Sunlight • Soil type • Nutrients • Still important for survival!

4. Levels of Organization • Organism – bear • Population (of one species) – group of bears • (biological) Community (interacting, living populations) – bears and other organisms that live nearby • Ecosystem (living and non-living) – woodland ecosystem • Biome (many ecosystems – similar climate) – temperate forest • Biosphere (all biomes on earth) – earth

5. Ecosystems and Their Energy

6. Ecosystem Interactions • Competition (resources) v. predation (plants too!) • Due to competition, chances for survival are increased when any one species uses the available resources in different ways. • Niche – role or position that an organism has in its environment • Habitat – area where an organism lives

7. Symbiotic Relationships • All examples of symbiosis – two (or more) species living closely together • Mutualism – two or more organisms that benefit from each other. • Commensalism – one organisms benefits, the other neither benefits nor is harmed (Nemo!). • Parasitism – one organism benefits, the other is harmed.

8. Flow of Energy in an Ecosystem • Autotroph – collects energy from the sun to produce food • Heterotroph – gets its energy by consuming other organisms • Herbivore • Carnivore • Omnivores • Scavengers – hyena • Detritivores or decomposers – eat and break down parts of dead organisms and retain their nutrients so they can be reused • What would happen if detitivores didn’t exist?

10. Models of Energy Flow • Food chains and food webs • Have different trophic levels • Where does energy begin? • Producers, Consumers (Primary, Secondary, Tertiary) • Each step in the food chain/web • Arrows represent the flow of energy • Why would we use webs instead of chains?

12. Energy and Biomass Pyramids

14. Nutrient Cycles

15. Nutrient cycles • Nutrients are chemical substances that an organism must obtain from its environment to sustain life and undergo life processes. • These nutrients are recycled so they can be reused! • Water cycle • Carbon cycle • Nitrogen cycle • Phosphorous cycle

16. Water cycle – review!

17. Carbon Cycle

18. Nitrogen cycle

19. Phosphorous Cycle

20. Energy Pyramids – Instructions • Pick a food chain and go to page 72-73 in your textbook (4 extras) • Trophic Level – using the appropriate term • Example – drawing (include word if not clear) • Side three • Numbers – how many organisms? (given for you) • Energy (Joules – unit of energy) and Biomass (total mass for one trophic level) – you are given base level, how will you find the rest? • Color, Cut, Fold, Affix, and you’re done!

21. cut here fold here Flow of energy: Example Pyramid 10,000n kg (biomass) 1,000n kg 100n kg 10n kg 10,000 J (energy) 10 J 100 J 1,000 J 3 40 250 6000 (numbers) Example food chain MAY NOT USE this one fold here fold here