1. What do the solid arrows represent?
What do the dashed arrows represent?
Can you trace a food chain from one of the producers to the bobcat?
Why is a food web a more accurate representation of feeding relationships in an ecosystem than a food chain?
Even though only one organism is shown in the food web, it represents all the individuals of the species.

2. Ecological Pyramids
Shows the relative amount of energy contained within each trophic level in a food chain

3. Trophic Levels Trophic – Greek “trophe” Producers= 1st trophic level
Food or nourishment
Producers= 1st trophic level
Consumers= 2nd level and higher

4. Trophic Levels Read from the bottom to the top of pyramid
1st trophic level- producers/autotrophs
Ex: Plants
2nd trophic level- primary consumers
Ex: Herbivores or omnivores
3rd trophic level- secondary consumers
Carnivores or omnivores
4th + trophic levels- tertiary or quad consumers
Ex: top predators- carnivores

5. Types of Pyramids “The 10% Rule” 1. Energy Pyramids
10% energy transferred up to next level as organisms feed on one another.
The rest is lost as HEAT.
“The 10% Rule”

6. Types of Pyramids 2. Biomass Pyramids
Biomass – total amount of organic matter present in a trophic level

7. Number of organisms at each trophic level. Higher # at LOWER levels.
Types of Pyramids
3. Pyramid of numbers
Number of organisms at each trophic level.
Higher # at LOWER levels.