1. What Shapes an Ecosystem?
Ecology
CHAPTER 3
What is Ecology?
Energy Flow
Cycles of Matter
What Shapes an Ecosystem?
How Populations Grow?

2. What is Ecology?
Ecology – study of interactions among organisms and between organisms & their environment
All living things depend on each other to survive
CIRCLE OF LIFE IDEA

3. Levels of Organization
Scientists study Ecology by examining interactions on every level
Species – organisms that are so similar to one another that they can breed and produce offspring
Populations
Communities
Ecosystems
Biome – group of ecosystems that have the same climate & similar dominant communities
Biosphere – extends 8 km above the surface & 11 km below the surface of the ocean

4. Energy Flow
Every organism needs to interacts with the environment to get energy to survive
Without a constant source of energy, living systems cannot function
Sunlight is the main energy source for life on Earth.

5. Producers/Autotrophs
Organisms that can use sunlight or inorganic chemicals to make their own food
Plants, Some Algae, Certain Bacteria
Are the base of all food chains & webs

6. Photosynthesis Process of converting sunlight into energy
CO H2O CHO O
Carbon dioxide + water >>> carbohydrates + Oxygen ↑
sunlight
Main Autotrophs that use photosynthesis:
1. land = plants
2. water = algae
3. wet ecosystems = cyanobacteria
(photosynthetic bacteria)

7. Chemosynthesis Hydrogen Sulfide + Oxygen = sulfur compounds
Process of converting chemicals into energy
Hydrogen Sulfide + Oxygen = sulfur compounds
↓↓↓
Chemical Energy
bacteria make CHO using carbon dioxide from sea water
Chemosynthetic Bacteria perform this process
Found in very remote places
1. volcanic vents on the deep ocean floor
2. hot springs in Yellowstone Park (Old Faithful)

8. Consumers/Heterotrophs
Organisms that rely on other organisms for their energy and food
Many different types:
1. herbivores – eats only plants
2. carnivores – eats only animals
3. omnivores – eats plants & animlas
4. detritivores – eat plant & animal remains & other dead matter
5. decomposers – breaks down organic matter

9. Feeding Relationships
When an organism eats another energy moves from the eaten to the eater
Energy flows in one direction thru an ecosystem
Sun or inorganic chemicals>> autotrophs >>> heterotrophs
Food Chain – a series of steps in which organisms transfer energy by eating and being eaten
Food Webs – a network of complex feeding interactions between many organisms
- links all the food chains in an ecosystem together

10. Trophic Levels Each step in a food chain or food web
Producers/Autotrophs ALWAYS make up the 1st level
Consumers make up all other levels
Each comsumer depends on the trophic level below it for energy

11. Food Chain

12. Food Web Top level consumer 3rd level consumer (carnivores)
2nd level consumer
(carnivores)
1st level consumer
(herbivores)
autotrophs

13. Ecological Pyramids
Diagram that represents the amounts of energy or matter contained within each trophic level in a food chain or food web
3 types:
1. Energy Pyramid
2. Biomass Pyramid
3. Pyramid of Numbers

14. Energy Pyramids
Shows the amount of energy available at each trophic level
Organisms use about 10% of this energy for life processes
The rest is lost to heat (90%)
The more levels the less energy is available for top consumers

15. Biomass Pyramids
Biomass – the total amount of living tissue within each trophic level
Represents the amount of potential food available for each trophic level in an ecosystem
Typically, the greatest biomass is available at the base of the pyramid (producers)

16. Pyramid of Numbers
Shows the number of individual organisms at each trophic level
If ecosystem has fewer producers than consumers, the pyramid would look more like a diamond

17. Ecological Pyramids Pyramid of Numbers Energy Pyramid Biomass Pyramid
Section 3-2
Pyramid of Numbers
Energy Pyramid
Biomass Pyramid
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