ENERGY IN ECOSYSTEMS ENERGY

Energy is transferred from one form to another In any energy conversion, some energy is lost. E goes from high to low quality High Quality is highly organized and compact Low 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 Free E H 2 O + CO 2 > C 6 H 12 O 6 + O 2

Free E Potential E Exergonic reaction C 6 H 12 O 6 + O 2 > H 2 O + CO 2

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 CO 2 + H 2 O + 4H 2 S + -> CH S + 3H 2 SO 4

Photosynthesis 6CO 2 + 6H 2 O > C 6 H 12 O 6 + 6O 2 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 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 pyramids Biomass & numbers pyramids

10% 90% Producer Secondary Primary Consumer 1,000 lbs 100 lbs 10 lbs Tertiary 1 lb 90% Energy Pyramid

1.2 nd Law of Thermodynamics 2.There is a limit to the size of animals. 3.Unusable tissue 4.Productivity of producers Aquatic : Nutrients(P) Terrestrial Nutrients(N), Temp. & Climate There is a limit to the links in a food chain