1. Semester 2, Day 2
Ecosystem & Energy

2. Agenda Turn in Cornell Notes & Question Responses Biodiversity Quiz
Ecosystem Lecture
4 Minute Break
Reading/Work Time
Hand Quizzes back and review

3. Turn in Cornell Notes and Question Responses
Order
Cornell Notes 34.1
Cornell Notes 34.2
Cornell Notes 34.3
Cornell Notes 34.4
Responses to Section and Chapter 34 Review
Make sure that your name is on your notes/responses
Initial each following page
Keep the papers together, fold the corner if not stapled

4. Biodiversity Quiz Complete the quiz silently
When you are finished, place quiz facedown on desk
When everyone is finished, pass quizzes forward

5. Ecosystem Changes How do certain changes affect an ecosystem?
Climate Changes
Temperature, flooding, global warming, freezing
Can eliminate entire biological communities
New communities will repopulate the area  NEW ECOSYSTEM!
From natural resources (volcanoes)

6. Ecosystem Changes How do certain changes affect an ecosystem?
Human Activity
Human-caused global warming, pesticides, deforestation, urban encroachment, endangered species, acid rain, water contamination, fossil fuels, dams for hydroelectricity, radioactive waste, oil spills, air pollution, soil erosion, salting roads, crop irrigation
All of these can kill populations, resulting in the entire ecosystem being disrupted

7. Ecosystem Changes How do certain changes affect an ecosystem?
Human Activity (cont.)
Smallmouth Bass
Dies from Lack
of Food
EFFECT
Spirogyra
Population
Explodes
EFFECT
Daphnia
Kill with
Pesticides
CAUSE
Bluegill
Dies from
Lack of Food
EFFECT

8. Ecosystem Changes How do certain changes affect an ecosystem?
Introduction of Non-Native / Invasive Species
Harmful
No predators
Displace native species
Carry disease
Population Size
Caused by humans
Example: Too many predators, prey die out, then predators die, and plants the prey ate grow out of control.

9. Population Size in Ecosystem
BIRTH
IMMIGRATION
EMIGRATION
DEATH
Rates that increase
population size
Rates that decrease
population size
Organisms enter ecosystem
Organisms enter ecosystem

10. Population Size in Ecosystem
Graph of Births and Deaths. Look at the gap between births and deaths.
Births
Gap gets bigger
Therefore, population INCREASES
Number of Organisms
Deaths
Time

11. Population Size in Ecosystem
Graph of Births and Deaths. Look at the gap between births and deaths.
Births
Gap gets smaller
Therefore, population INCREASES
Number of Organisms
Deaths
Time

12. Population Size in Ecosystem
Graph of Births and Deaths. Look at the gap between births and deaths.
Births
Gap stays the same
Therefore, population INCREASES
Number of Organisms
Deaths
Time

13. Energy Flow in an Ecosystem
Autotrophs: produce their own food. 2 types:
Autotrophs make ENERGY available for all other organisms in the ecosystem.
Phototrophs
Chemotrophs
Organisms with chlorophyll
Chlorophyll absorbs light energy for photosynthesis
Converts light energy to food energy
When sunlight is unavailable
Hydrogen sulfide (H2S) or carbon dioxide (CO2) converted to organic (“life”) molecules.
“self”
“Light”
“Chemical”

14. Energy Flow in an Ecosystem
Heterotrophs: get energy by consuming other organisms.
Note: Decomposers: secrete enzymes to break down dead matter & then absorb the nutrients (bacteria and fungi)
Herbivore
Carnivore
Omnivore
Detritivore
Organisms that consume dead matter (any).
Tend to be bugs.
Organisms that consume only plants
Organisms that consume only other heterotrophs
Organisms that consume both autotrophs and heterotrophs
AKA “Consumers”

15. Energy Flow in an Ecosystem
Decomposers & Detritivores are similar, BUT
DECOMPOSERS Secrete enzymes to break down Absorb nutrients Bacteria, Fungi
DETRITIVORES Eat & digest Bugs (generally)
*Note: Scavengers technically eat dead organisms, but will also eat live organisms
Dead Matter

16. Arrow shows direction of ENERGY
Energy Flow: Food Webs
Food Chain: simple model; one-way energy flow
Primary Producer  Primary Consumer  Secondary Consumer  Tertiary Consumer
*Note:
All primary producers are autotrophs
All primary consumers are herbivores (a type of heterotroph)
Higher consumers can be omnivores OR carnivores
Arrow shows direction of ENERGY

17. Energy Flow: Food Web
Food Web: Interconnected food chains; complex

18. Energy Flow: Ecological Pyramids
Ecological pyramids: show relative amounts of energy, biomass, or # of organisms.
Tertiary Consumer
Secondary Consumer
Primary Consumer
Primary Producer
Trophic Levels
Template

19. Energy Flow: Ecological Pyramids
Pyramid of Energy
0.1%
1% Energy
10% Energy
100% Energy
Energy Lost as Heat (90%)
Available
Energy
Decreases

20. Energy Flow: Ecological Pyramids
Pyramid of Biomass (total mass of each level)
1.5 g/m2
11 g/m2
37 g/m2
809 g/m2
Note: Mass/Area
Available
Biomass
Decreases

21. Energy Flow: Ecological Pyramids
Pyramid of Numbers (# of Organisms)
10,000
90,000
200,000
1,500,000
Population
Size
Decreases

22. 4 Minute Break Stay on this floor, otherwise privilege will be revoked
Be back in the class by ______.

23. Reading / Work Time Read Chapter 2
Do the Chapter 2 Assessment Questions #1-15, 17-24
Come show me your responses when you are finished.
If you don’t finish, it is homework!

24. Reminder
dp.davincischools.org/staff/blarkin