1. Energy Flow in Ecosystems
Chapter 3

2. The capacity to do work Thermodynamics is the study of energy.

3. 1st Law of Thermodynamics
When energy is converted from one form to another in a physical or chemical change, no energy is created or destroyed

4. 2nd Law of Thermodynamics
Whenever energy is changed from one form to another, we end up with lower-quality or less usable energy than we started with

5. Initial Energy in Ecosystems
Sun – Photosynthesis
Chemical – Chemosynthesis
Energy is converted by producers(autotrophs)
Basis for energy transfer (food chain)

6. 6CO2 + 6H2O —> C6H12O6 + 6O2 carbon water glucose oxygen dioxide
Photosynthesis
6CO2 + 6H2O —> C6H12O6 + 6O2 carbon water glucose oxygen dioxide

7. Chemosynthesis
Video in picture

8. Primary Productivity
The fabrication of carbon compounds through photo or chemo- synthesis
Gross Primary Productivity
Rate at which producers can convert solar energy into biomass
Net Primary Productivity
Rate at which producers make & store products while accounting for the producers own energy requirements
GPP – Respiration = NPP (mg/L/day) or (Kcal/day)

9. Net Primary Productivity

10. Trophic Levels
Feeding Levels

11. Trophic Level Organisms
Organisms are identified by the food they consume 2nd trophic level and above

12. Eat producers Primary consumers Example: Deer, rabbits, cows
Herbivores
Eat producers Primary consumers Example: Deer, rabbits, cows

13. Carnivores
Eat meat (other animals) Secondary+ consumers Example: Lion, frog, ladybug

14. Eat plants & meat Secondary+ consumers Example: Raccoon, bear, human
Omnivores
Eat plants & meat Secondary+ consumers Example: Raccoon, bear, human

15. Other consumers…. Scavengers Decomposers Detritivores
Eat dead organisms
Decomposers
Break down & recycle dead organisms
Detritivores
Live off detitrus
Detritus – dead parts & waste from organisms

16. Food Webs Arrows represent energy flow
Food webs can be disrupted by many factors
Keystone species
Invasive species