1. Energy Flow in Ecosystems
Spring 2018

2. Question
Why are food chains generally limited to three or four levels? ANSWER There is not enough energy at the top of a food chain to support another trophic level.

3. Energy Flow In Ecosystems
Energy flows through an ecosystem in ONE direction
From the sun or chemical compounds
To autotrophs (aka producers)
Then to various heterotrophs (aka consumers)

4. Food Chains Food chains-
Shows how matter and energy move through an ecosystem in a series of steps
Shows which organisms transfer energy by eating and being eaten.
Each organism in a food chain represents a feeding step or trophic level.
The feeding step represents the transfer of matter and energy,

5. Examples of a Marine Food Chain
Zooplankton
Phytoplankton
Fish
Squid
Shark

6. Food webs- models that show all possible feeding relationships.
Shows relationships at each trophic level in a community.
Links all food chains in an ecosystem together.
Ecological pyramid- diagram that shows various amounts of energy or matter at each trophic level.
There are 3 different types

7. Energy Pyramid Snake 10KCal Mice 100 KCal Insects 1,000KCal
Producers 10,000 KCal

8. Biomass Pyramid
Human 80 grams
Chickens 800 grams
8,000 grams Grain

9. Pyramid of Numbers
1 Fox
26 Birds
250 Grasshoppers
3000 Grasses