1. What is Ecology?
The study of how organisms interact with each other and their environment.
Environmental conditions include:
Biotic factors (living)
Abiotic factors (nonliving)

2. Levels of Organization

3. - All of a species in an area - All biotic factors in an area
Definitions:
- One organism
- All of a species in an area
- All biotic factors in an area
- All biotic and abiotic factors in an area
- A major region
- All regions of the Earth where life exists
forest, grassland, freshwater, marine, desert, and tundra

4. Sunlight is the main energy source for life on earth.
Energy Flow
Sunlight is the main energy
source for life on earth.

5. Autotroph
An organism that is able to capture energy from sunlight or chemicals and use it to produce its own food
Also called a producer
Who: all plants, some algae and bacteria

6. Heterotroph
An organism that obtains food by consuming other living things
Also called a consumer
Herbivore: eat plants
Carnivore: eats animals
Omnivore: eats both plants and animals

7. Detritivore: scavengers that feed on remains and other dead matter
Ex. Mites, earthworms,
snails, crabs
Decomposer: break down organic matter
Ex. Bacteria, fungi

8. Feeding Relationships
Energy flows through an ecosystem in one direction.
Trophic level: each step in a food chain or food web
Food chain: a series of steps in which organisms transfer energy by eating and being eaten

10. Food Web
Network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem

11. Also called: Tertiary Consumers ----- Secondary Consumers
Primary Consumers
Autotrophs
*The arrows mean energy transfer; the arrrow go towards the organism eating
G here

12. Ecological Pyramid
An illustration of the relative amounts of energy or matter contained within each trophic level in a given food chain or food web
Energy
Biomass
Numbers

13. Pyramid of Energy
Organisms consume others to gain energy for life processes (respiration, movement, reproduction)
Only about 10% of the energy consumed is stored in their tissues and available for the next trophic level

14. Where Does That Energy Go?

16. Pyramid of Biomass The total amount of living tissue at each level
D here

17. Pyramid of Numbers
The number of individual organisms at each level

18. Biogeochemical Cycles
Matter is recycled.
A process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another
Nutrients and water may be outside or inside organisms.

19. Water Cycle Water moves between oceans, atmosphere, and land.
Transpiration: loss of water from a plant through its leaves

20. Carbon Cycle Primary source of carbon in our atmosphere???
Photosynthesis
Cellular Respiration
Burning fossil fuels
Decomposition of
dead matter
Primary source of carbon in our atmosphere???

21. Which 3 processes
return carbon to the
environment?
Respiration
Burning fossil fuels
decomposition
What process removes carbon from the environment and incorporates it into living things?

22. The dangerous Greenhouse effect
CO2 is a gas that hold in heat
Too much CO2 (combustion, respiration, and decomposition) increases CO2
traps more heat
global warming 

23. Nitrogen Cycle Primary source of nitrogen? Atmosphere! 78% is nitrogen
Bacteria are essential to obtaining nitrogen from the atmosphere.
Primary source of nitrogen? Atmosphere! 78% is nitrogen

24. Primary source of nitrogen? Atmosphere! 78% is nitrogen

25. Nitrogen fixation
Certain kinds of bacteria can convert nitrogen gas into nitrogen compounds (ammonia) that plants can absorb and use
These bacteria live in the soil and on the roots of legumes
Denitrification: soil bacteria that reverse this process