1. Chapter 11: Ecosystems & Resources
11.3: Energy flows through ecosystems
United streaming video: The_Science_of_Plants__Grades_06_08__Environmental_Enclaves

2. Review
Serena puts a small amount of water in a saucer and leaves it on a sunny windowsill for several hours.
What happens to the water? Why?
The water evaporates. Heat from the Sun changes liquid water into vapor, which escapes into the air. After several hours the saucer may be completely dry.

3. Living things capture and release energy
All of our life processes require energy
The energy we use is chemical energy, from the food we eat (chemical bonds of sugars break and release energy)
While running, we use energy, and some is lost as heat (through sweating)
Most energy comes directly or indirectly from the __________ .
Living things must capture this energy and store it in a usable form
Sun

4. Producers
Producer: an organism that captures energy and stores it in food as chemical energy
Make energy available to the rest of the ecosystem
Energy usually enters the ecosystem through photosynthesis
Produce sugars, and chemical energy is released when these are broken down

5. Producers Plants are the most common producers on land
Photosynthetic bacteria and algae are the most common in waters
Sun provides most energy stored in food
Bacteria in the deep ocean perform chemosynthesis: they produced food using heated chemicals from hydrothermal vents
Producers: “produce food for themselves and for the rest of
the ecosystem”

6. Consumers
Consumers: organisms that get their energy by eating, or consuming, other organisms
Classified by their position in a feeding relationship: Producer primary consumer secondary consumer  etc.
Used to study how energy flows through an ecosystem

7. Decomposers
Decomposers: organisms that break down dead plant and animal matter into simpler compounds
Clean-up crew
Leaves left on a forest floor, dead roots and branches, animal remains and waste materials
All broken down by fungi and bacterial that live in th soil
A pinch of soil may contain almost ½ million fungi and billions of bacteria
Energy gets used as it flows from organism to organism
Decomposers
release the last bit of energy from once-living matter
return matter to soil or water to be used again

10. Ocean Ecosystem

11. Models help explain feeding relationships
Used to show the feeding relationships that transfer energy from organism to organism
Food chains and food webs
Food chain: links that are connected one by one
Describes the feeding relationship between a producer and a single chain of consumers in an ecosystem
Arrows represent the flow of energy
Food web: feeding relationships between many different consumers and producers
More complex feeding relationships
Both show how different organisms receive their energy and how they depend on one another

13. Food chain vs Food web

14. Available energy decrease as it moves through an ecosystem
Energy pyramid: show the amount of energy available at each feeding level of an ecosystem

17. ` Pt I: (below) Pt II: (on right)
Construct a Food web using the following animals. 
This ecosystem represents a farm area. 
The corn is the main source of food for many of the herbivores in the area.
SNAKE,  CORN , CATERPILLAR, DEER, CROW, MOUSE, COUGAR, SQUIRREL, MICROORGANISMS (decomposers)