1. Please take out your Chapter 3 Reading Assignment (Module 6 is due)
APES 10/2
Please take out your Chapter 3 Reading Assignment (Module 6 is due)

2. Unit One Test Results Multiple Choice Short Answer A = 24.5-27
B =
C = 19-21
D =
Class Average = 21.07, 21.79
Retakes for scores of 18 and below are available this week during Power Hour
Class Average = 7.2, 7.8 Retakes for scores of 6.5 and below Retakes can improve your score up to a 70% You can take one or both sections

3. Check your work!
Module 6: 1. A 2. D 3. A 4. C 5. B 6. E GPP – Respiration = NPP

4. Chapter 3 Quality Check 6, 11, 12b.
WRITE THEM DOWN WORD-FOR-WORD. NO CHANGES!

5. EcoColumns Time Today: Finish construction
Rinse water through the column twice
Add leaf litter, bugs, seeds to the top

6. Food Webs and Energy

7. Levels of Organization
Biosphere
Biomes
Ecosystems
Communities
Populations
Individuals
Cells/
Tissues
Living things
can be studied
at many levels:
In Ecology,
we will study
everything
above
individuals

8. Levels of Organization
Biosphere: Our earth!
Biome: areas of biosphere that have similar climate, plants, and animals
Ecosystem: collection of living and non-living things that make up an environment
Desert
Biome
Old Growth Forest Ecosystem
Biosphere

9. Levels of Organization
Community: populations of different species living together (ex: humans and bacteria living together)
Population: group of one species living together
Species: a group of organisms that can only breed with each other
Population of prairie dogs
(a species)
Community of macaws, grasses, insects…

10. Energy Flow Through Ecosystems Section 3.2

11. What do Ecosystems Need?
For ecosystems to thrive, its members need energy and matter
Matter = liquid, solid, and gas ‘stuff’
Energy moves in a one-way flow, while matter recycles.
Today’s focus = energy

12. Energy for Ecosystems
The sun provides the initial energy for ecosystems
Plants harvest sunlight and turn light energy into chemical energy (glucose)
This is called photosynthesis
CO2 + H2O + light glucose + O2
In an ecosystem, we call plants producers

13. Energy for Ecosystems
Chemical energy (glucose) stored in plants is passed on to herbivores, which eat the plants
Chemical energy in herbivores (protein, fat, sugar) is passed on to carnivores, which eat the herbivores
This forms a food chain/web.

14. ENERGY ALWAYS FLOWS THE SAME WAY THROUGH AN ECOSYSTEM:
Sun Producers Consumers
Energy does not recycle. It is lost as heat when organisms burn it off!

15. How is the chemical energy used?
Plants AND consumers use the energy in sugar for cellular respiration.
Glucose + O2
CO2 + H2O + ATP
It’s converted to a smaller, more useable molecule called ATP, which is converted to kinetic energy.

16. Players in the Food Web
Plants are called producers, and also autotrophs
Autotroph = makes own food using sunlight
First level consumers eat producers
Second level consumers eat first level consumers, and so on
Consumers are also called heterotrophs
(get food/energy from outside source)

17. Practice Time Watch the Planet Earth video clip
Make a food web on your whiteboard
Label producers (P), 1st, 2nd, 3rd level consumers, detritivores, decomposers (inferred)
Put a star next to heterotrophs

18. Other Players
Detritivores (mites, snails, and worms) feed on dead matter
Decomposers (bacteria and fungi)
break down dead matter

19. Trophic Levels
Each step along a food chain or web is called a trophic level
Producers are the first trophic level
Consumers make up the second, third, and higher trophic levels
Also called primary, secondary, tertiary consumers

20. Energy Pyramids
The energy that producers and consumers can possibly make and pass on can be represented in an energy pyramid
Because producers photosynthesize and are numerous, they are on the bottom of the pyramid

21. Pyramid of Energy Example
-Students jot down this pyramid of energy in notes (don’t need pictures). Important to include trophic level labels (producer, primary consumers, etc.)
-The “J” stands for joules. Joules are a measure of energy. Calories are another measure of energy.
-Ask students: Quantitatively, what do you notice about how the amount of energy decreases each step through the food chain?
-Notice that each trophic level generally gets ~10% of energy from previous trophic level. This is called the 10% rule.

22. Measures of Energy in Ecosystems
Gross Primary Productivity (GPP) = total solar energy captured by plants (ONLY ABOUT 1%)
Net Primary Productivity (NPP) = total energy captured minus the energy used by producers for their own respiration (what’s left over for consumers!)
NPP = GPP – Respiration by Producers

23. Practice Problem
A forest has an NPP of 1.4 kg C/m2/year and the rate of cellular respiration is 2.4 kg C/m2/year. What is the GPP?
NPP = GPP – Respiration
1.4 = GPP – 2.4
GPP = = 3.8 kilograms of Carbon per square meter per year

24. Biomes Differ in NPP

25. Ecological Efficiency
Proportion of energy that is passed between trophic levels, after cellular respiration
10% on average!
-Students copy this definition
-Ask students to think: why do you think this happens? Think of the game from yesterday. (go to next slide as you talk about this)

26. 10% rule...
10%
90% lost as heat

27. How much energy is at each level?
1000 Cal
? Cal

28. How much energy is at each level?
9 Cal as heat
1000 Cal
100 Cal
10 Cal
1 Cal
90 Cal as heat
900 Cal as heat

29. Pyramid of Biomass At which level is the most biomass located?
Biomass= total mass of living matter in an area
At which level is the most biomass located?

30. Pyramid of Biomass Same as pyramid of energy
1000 grams
600 grams
200 grams
100 grams
Same as pyramid of energy
More mass in bottom trophic levels

31. Due Next Time
Wetlands FRQ