1. 13.1 KEY CONCEPT Ecology is the study of the relationships among organisms and their environment.

2. Ecologists study environments at different levels of organization.
Ecology is the study of the interactions among living things, and between living things and their surroundings.
Example: Salmon
Over 140 species eat salmon
Important for economy
Important for health of river systems

3. An organism is an individual living thing, such as an alligator.

4. A population is a group of the same species that lives in one area.
Organism

5. A community is a group of different species that live together in one area.
Population
Organism

6. An ecosystem includes all of the organisms as well as the climate, soil, water, rocks and other nonliving things in a given area.
Ecosystem
Community
Population
Organism

7. Biome
A biome is a major regional or global community of organisms characterized by the climate conditions and plant communities that thrive there.
Ecosystem
Community
Population
Organism

8. Concept Check: Organism, Population, Community, Ecosystem, Biome
Desert
Cricket
River
Barrel of monkeys
Decayed Log
In your notes, give an example of each of the five levels. They should build on each other!

9. 13.2 KEY CONCEPT Every ecosystem includes both living and nonliving factors.

10. Create 2 columns in your notes, one labeled Biotic, the other Abiotic
Create 2 columns in your notes, one labeled Biotic, the other Abiotic. Classify each thing below.
Water
Fish
Paper
Glass
Aluminum
Wooden ruler
Sand
Clouds
Snail
Air
Steak
Salad
Bread
Hair
Finger nails
Pipe
Cotton fabric
Gold
Plastic
Grapes

11. An ecosystem includes both biotic and abiotic factors.
Biotic factors are living things.
plants
animals
fungi
bacteria
plants

12. Abiotic factors are nonliving things. moisture temperature wind
sunlight
soil
moisture
sunlight
What is the first level of organization that includes abiotic factors?
Populations
Biome
Ecosystem
Community

13. Changing one factor in an ecosystem can affect many other factors.
Biodiversity is the assortment, or variety, of living things in an ecosystem.
Rain forests have more biodiversity than other locations in the world, but are threatened by human activities.
Only 7% of the world’s surface
50% of the world’s plant and animal species

14. A keystone species is a species that has an unusually large effect on its ecosystem.

15. Keystone species form and maintain a complex web of life.
Examples: Beaver, Salmon
creation of
wetland
ecosystem
increased waterfowl
Population
increased fish
population
nesting sites for birds
keystone species

16. 13.3 KEY CONCEPT Life in an ecosystem requires a source of energy.

17. Producers provide energy for other organisms in an ecosystem.
Producers - energy from non-living resources.
Producers are also called autotrophs…why?
Basis for EVERY ecosystem!
Dark green = heavy forestation, a lot of producers
Yellow = very few producers

18. Producers provide energy for other organisms in an ecosystem.
Consumers - energy by eating
Consumers are also called heterotrophs…why?

19. Almost all producers obtain energy from sunlight.
Photosynthesis in most producers uses sunlight as an energy source.
How do we, as humans, get the energy from the sun?
Chemosynthesis in prokaryote producers uses chemicals as an energy source.
carbon dioxide + water +
hydrogen sulfide + oxygen
sugar + sulfuric acid

20. 13.4 KEY CONCEPT Food chains and food webs model the flow of energy in an ecosystem.

21. Choose any three organisms and use them to fill in the food chain below
Producer
Herbivore/Omnivore
Carnivore/Omnivore
Grass
Cow
Human
Plankton
Whale
Shark

22. A food chain links species by their feeding relationships.
A food chain is a model that shows a sequence of feeding relationships.
A food chain links species by their feeding relationships.
A food chain follows the connection between one producer and a single chain of consumers within an ecosystem.
REMEMBER…Arrows show the direction the ENERGY moves!!
DESERT COTTONTAIL
GRAMA GRASS
HARRIS’S HAWK

23. Consumers are not all alike. Herbivores eat only plants.
Carnivores eat only animals.
Omnivores eat both plants and animals.
Detritivores eat dead organic matter.
Decomposers are detritivores that break down organic matter into simpler compounds.
carnivore
decomposer

24. Specialists are consumers that primarily eat one specific organism or a very small number of organisms.
Generalists are consumers that have a varying diet. Do not have a single source of food.

25. Trophic levels are the nourishment levels in a food chain.
Primary consumers are herbivores that eat producers.
Secondary consumers are carnivores that eat herbivores.
Tertiary consumers are carnivores that eat secondary consumers.
Omnivores, such as humans that eat both plants and animals, may be listed at different trophic levels in different food chains.

26. A food web shows a complex network of feeding relationships.
An organism may have multiple feeding relationships in an ecosystem.
A food web emphasizes complicated feeding relationships and energy flow in an ecosystem.