1. Ecology

2. Ecology
Ecology is the study of interactions between different kinds of living things and their environment.

3. Why is Ecology Important?

4. Why care about ecology?
Ecological research provides us with the necessary info. to resolve many of the environmental problems that surround us.

5. We are dependent upon the world’s ecosystems, therefore, we must learn how to keep the environment safe for all living organisms.

6. Biosphere The portion of Earth that supports life
Several kilometers below ocean’s surface and several kilometers into the atmosphere

7. Biotic Factors Living things with which an organism interacts
Animals, plants, fungi, & microorganisms

8. Abiotic Factors Nonliving factors in an organism’s environment
Temperature, rainfall, sunlight
Air or water currents
Type & acidity of soil
Availability of nutrients

9. Population
A group of a single species that lives in a given area at the same time
Ex: school of fish
Compete for same resources

10. Biological Community
A group of interacting populations that occupy the same geographic area at the same time

11. Ecosystem
A biological community AND all of the abiotic factors that affect it.

12. Biome
A large group of ecosystems that share the same climate and have similar types of communities
We’ll cover more in Ch. 3

13. Habitat
An area where an organism lives.
Ex: Tree or a grove of trees

14. Niche The role or position that an organisms has in its environment
How the organism meets its needs for food, shelter and reproduction.

15. Predation One organism consuming another organism for food
Predator eats the prey
Ex: Cougar eats a rabbit

16. Symbiotic Relationships
Symbiosis - Close relationship that exists when two or more species live together
Mutualism, Commensalism, Parasitism

17. Mutualism Both organisms benefit Ex: Lichens - between fungi and algae
Algae provides food for fungi and fungi provide a habitat for the algae

18. Commensalism
One organism benefits, the other is neither helped nor harmed
Ex: Clownfish and sea anemones
sea anemones protect & provide food for the clownfish
clownfish neither benefits nor harms the sea anemones

19. Parasitism One organism benefits at the expense of another
Ex: Dogs & heartworms, ticks, fleas, tapeworms
Do not always kill the host - harm it

20. Plants are primary producers
Energy in an Ecosystem
Plants are primary producers
Producers are also called autotrophs (self-feeding)
Produces its own food by collecting energy from sunlight or inorganic substances

21. Consumers Consumers cannot collect energy directly from the sun
Consumers must eat other organisms in order to obtain energy
Animals and bacteria are consumers
Animals are also called heterotrophic because they must feed on other organisms to obtain energy

22. Heterotrophs Must consume other organisms to get its energy Herbivores
Carnivores
Omnivores
Parasites
Decomposers
Detritivores

23. Herbivores Herbivores obtain energy by eating autotrophs (plants)
= Primary (1o) consumers

24. Carnivores Carnivores obtain energy by eating other animals
Secondary (2o) or Tertiary (3o) consumers
heterotrophs that prey on other heterotrophs

25. Omnivores
Omnivores are animals that eat both plants and animals

26. Detritivores
Eats fragments of dead matter in an ecosystem, and returns nutrients to the environment
Ex: worms, aquatic insects on stream bottoms

27. Decomposers
Decomposers break down dead organisms by releasing digestive enzymes
Ex: Fungi & bacteria

29. Energy Flow
The source of energy (for most ecosystems) is the sun
Energy and nutrients are passed from organism to organism through the food chain

30. Ultimately, energy will be LOST as HEAT
It does not continuously cycle
Black arrows
Nutrients, however, continuously CYCLE through food webs and through the geological world.
White arrows

31. Trophic Levels
Feeding level in the flow of food energy from producers to the highest level of consumers
Primary (1o), secondary (2o) & tertiary (3o) consumers
See ecological pyramids on p. 44

32. Only 10% of the energy in one trophic level is passed on to the next level
The rest is used by the organism or lost as heat

33. Biomass - combined mass of all the organisms in that trophic level
As the trophic level increases, biomass decreases
not everything in the lower levels gets eaten
not everything that is eaten is digested
energy is always being lost as heat

34. Food Chain
A simple, straight-line sequence of organisms consuming other organisms
Grass grasshopper  mouse  hawk

35. Food Web
Complex feeding relationships that result from interconnecting food chains
See p.43

37. Review
What factors are included in an ecosystem that are not included in a community?
Describe how ecosystems and biomes differ.
How is a habitat different from a niche? Example?
Compare/contrast food chains and food webs.