1. Environmental Science
Chapter 5 – How Ecosystems Work

2. Photosynthesis
Plants use energy from the sun to make their own food… carbohydrates

3. Producer
An organism that makes its own food through photosynthesis or chemical sources; also called an autotroph.

4. Consumers
An organism that gets its energy by eating other organisms, either producers or consumers; also called a heterotroph.
Therefore, consumers get their energy indirectly.

5. Herbivores
Obtain their energy only from producers.

6. Carnivores
Obtain their energy only from other consumers.

7. Eating Insects

8. Omnivores
Obtain their energy from both producers & consumers.

9. Decomposers
Fungi & bacteria break down organisms in an ecosystem & returns nutrients to soil, water, & air

10. Trophic Level
Each step through which energy is transferred in a food chain
If a fish eats a plant, and then a bird eats the fish, only about 10% of the energy from the original plant is available for the bird.

11. Nitrogen & Nitrogen Fixing Bacteria
Makes up approximately 78% of our atmosphere
Only certain kinds of bacteria found in the roots of legumes can transfer nitrogen from the atmosphere into chemical compounds suitable to build proteins

12. Succession
Is possible because newer species make environment less suitable for previous species.

13. Primary Succession Begins where there is no soil
Examples: new islands created by volcanoes, rocks exposed by glacial retreat, or any other surface that has not previously supported life
Much slower than Secondary Succession

14. Lichen Often a pioneer species in primary succession
Breaks rock down into soil

15. Secondary Succession More common than Primary Succession
Occurs on a surface where an ecosystem previously existed but is disrupted by humans, animals, or natural processes
Examples: Storms, Floods, Earthquakes, Forest Fires, Volcanoes

16. Benefits of Forest Fires & Prescribed Burns
Fires benefit some forest communities by allowing some trees to release seeds, clearing away deadwood, & encouraging new growth.

17. Climax Community
Final & Stable Community that develops during succession.

18. Old Field Succession Occurs when farmland is abandoned.
Taller grasses eventually replace pioneer weeds.
After approximately 150 year, a tall mature oak forest is likely to form.

19. Where would a scientist be least likely to study primary succession?
New Volcanic Island
Gravel Filled Valley
Abandoned Parking Lot
Tropical Rain Forest

20. Where would a scientist be least likely to study primary succession?
New Volcanic Island
Gravel Filled Valley
Abandoned Parking Lot
Tropical Rain Forest

21. Where would a scientist be most likely to study secondary succession?
Breaking Down of Bare Rock by Lichen
Pioneer plants Growing in a Glacial Valley
Appearance of Weeds in Concrete Cracks
A Forest Burned Down By Fire

22. Where would a scientist be most likely to study secondary succession?
Breaking Down of Bare Rock by Lichen
Pioneer plants Growing in a Glacial Valley
Appearance of Weeds in Concrete Cracks
A Forest Burned Down By Fire

23. Carbon Cycle
Process by which carbon is cycled between the atmosphere, land, water, & organisms.

24. Carbon Cycle
Humans impact the carbon cycle by burning fossil fuels that release carbon dioxide into the air. (Global Warming)

25. Carbon Cycle
Plants impact carbon cycle by enabling carbon to enter ecosystem through photosynthesis.