1. Communities & Ecosystems
10/ p 🔺
Communities & Ecosystems
Living Organisms Interacting with Each Other & Their Environments

2. Main Idea:
Organisms both cooperate and compete to increase the chances of survival and reproduction.

3. Two key processes of ecosystems: Energy flows & chemicals cycle
Energy flows within food chains from the sun, through plants, animals and decomposers; most is lost as heat (calories).
Chemicals are recycled among air, water, soil and organisms.
36.8

4. Food Chains A food chain is the stepwise flow of energy and nutrients:
Plants: producers
Herbivores: primary consumers
Carnivores: secondary & tertiary consumers
Food Chains

5. Food Web Several food chains connected make a food web
*Note the direction of the arrows:

7. Decomposers
The break down of organic compounds to inorganic compounds is called “decomposition”.
“Detritivores” or “Recyclers” (animal scavengers, fungi and bacteria) decompose waste matter and recycle nutrients.

9. Energy supply limits the length of food chains.
Productivity: what organisms
do with the energy they get.
Secondary
Primary

10. Where does the energy go?
Used through:
cellular respiration
heat
10% or less of the energy is stored at each trophic level and available to the next level.
energy loss limits most food chain to three to five levels.

11. An energy pyramid explains why meat is a luxury for humans.
Because the energy pyramid tapers so sharply, a field of corn or other plant crops can support many more vegetarians than meat-eaters. 1%
10%
10%
100%
100%
36.12

12. 10/15-16 ⭐ Food Web Simulations p.17
Website #1:
Run the simulation with a change to one population.
Construct a data table in your notebook showing what you changed, and the final effects on each population.
Repeat the simulation again with a new change and record results in your data table.
Website #2:
Play the food web game.
Diagram your completed food web in your notebook (you can use names in your diagram).
Show Mr. Beckstead your score before you exit the game