1. Chapter 10 Ecosystems p

2. What is an ecosystem?
A community of living organisms interacting with one another and with non-living parts of the environment they live in
Individual population community ecosystem
Examples: forest, lake, island, mountain

3. Trophic relationships
Feeding connections among living organisms in an ecosystem
Can be represented by a food chain (p.319)
3 trophic levels:
Producers
Consumers
Decomposers

4. Producers Plants Autotrophic (self feeding)
Convert carbon dioxide to glucose with help of solar energy
Beginning of food chain, they introduce energy to an ecosystem

5. Consumers Heterotrophic (feed on other living organisms) 4 types:
Primary or 1st order (herbivores), feed on producers (plants)
2nd, 3rd, 4th order consumers, eat consumers of preceding order (usually carnivores, can also be omnivores)

6. Decomposers
Organisms that feed on waste and remains of other living organisms (dead leaves, wood, animal remains, excrement, etc.)
Examples are worms, fungi, bacteria, some insects

7. Trophic networks More than one food chain is possible in an ecosystem
This means there are many trophic relationships
A trophic network illustrates all of them

8. Material flow and chemical recycling
Matter an energy are constantly exchanged between organisms
Matter is recycled when decomposers break down organic matter into inorganic matter
This allows an endless cycle of exchange in an ecosystem

9. Flow of inorganic matter Flow of organic matter
Decomposers
Detritus
Consumers
Producers
Environment
Flow of inorganic matter
Flow of organic matter

10. Energy Flow
From one trophic level to another energy is lost (waste, movement, growth, reproduction, heat)
Only 10% of energy is available at next level
Energy IS NOT recyled, we need a constant supply from the sun (p.325)

11. Primary productivity in ecosystems
The amount of new biomass generated by producers (energy available from plants)
limits the # of organisms that can live in an ecosystem
Influenced by:
Sunlight
Water
Nutrients
Temperature

12. Disturbances Events that damage an ecosystem
Can lead to elimination of organisms or can alter the availability of resources
2 types:
Natural, such as storms, flooding, forest fires, volcanic eruptions, drought, etc.
Human, such as litter, logging, oil spills, etc.

13. Ecological succession
Series of changes that occur in ecosystems after a disturbance.
Continue until a balance is restored