1. Principles of Ecology
See New Kent PPT for SOL questions and string food web activity

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.
Biosphere – portion of earth that supports life!

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.
Mutualism – coral. Coral protects, algae provides nutrients!

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?

9. Wood louse decomposing dead plants!

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

13. How do the two relate?

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! Continuing from last class…
What are the names of these processes? Precipitation, Condensation, Evaporation, Transpiration, Percolation, Runoff (movement of water on the land)

17. Carbon Cycle
All living things contain carbon!

18. Nitrogen cycle
Nitrogen fixation – bacteria and lighting so plants can use.
Ammonification – bacteria convert organic to ON to ammonia when animals die.
Nitrification – most plants cannot use ammonium as a form of nitrogen.
Denitrification – back into the atmosphere

19. Phosphorous Cycle
Again, sources and sinks

20. Energy Pyramids – Instructions
Pick a food chain and go to page 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!
RAM JAM!!!

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