E N E R GY I N E C O S Y S T E M S

ENERGY

Energy is transferred from one form to another

In any energy conversion, some energy is lost. E goes from high to low qualityHigh Quality is highly organized and compactLow quality is dispersed

2nd Law of Thermodynamics

Everything has a cost

Entropy: Without energy to organize the system, it falls to disorder

Endergonic reaction

Potential E

Potential E

Free E

Free E

H2O + CO2 > C6H12O6 + O2

Free E

Free E

Potential EPotential E

Exergonic reaction

C6H12O6 + O2 > H2O + CO2

Ecosystems depend on the ability of organisms to convert inorganic compounds into food

• Initial energy comes from the sun or chemicals – Autotrophs/producers • Convert inorganic compounds into organic compounds

– Photosynthesis– Chemosynthesis

– Energy is transferred through trophic levels• Producer>primary consumer > secondary > tertiary

Energy flow through an ecosystem

ENERGY in ecosystems Hydrothermal vents

Chemosynthesis • Tubeworms mine for sulfide in the carbonate

substrate with their roots• Bacteria living in the tubeworm metabolizes

the sulfide and produce chemosynthetic energy that sustains them both

• CO2 + H2O + 4H2S + -> CH20 + 4S + 3H2SO4

•

Photosynthesis • 6CO2 + 6H2O > C6H12O6+ 6O2

• 50% of sunlight reaches earth’s surface

• 43 percent of the total radiant energy from the Sun is in the visible parts of the spectrum

• Most of the visible light that plants use is in the 420-680 nm range

• 1 man eats• 300 trout for a year eat• 90,000 frogs that eat• 27,000,000 grasshoppers that

consume• 1,000 tons of grass

Ecological pyramidsBiomass & numbers pyramids

10%

10%

10%90%90%

Producer

SecondaryPrimary Consumer

1,000 lbs100 lbs10 lbsTertiary1 lb

90%

Energy Pyramid

1. 2nd Law of Thermodynamics2. There is a limit to the size of animals. 3. Unusable tissue4. Productivity of producers

Aquatic : Nutrients(P) Terrestrial Nutrients(N), Temp. & Climate

There is a limit to the links in a food chain