Two basic processes must occur in an ecosystem

Two basic processes must occur in an ecosystem: 1. A cycling of chemical elements. 2. Flow of energy. Energy flows through systems while materials circulate around systems.

Thermodynamics is the study of the energy transformations that occur in a system. • It is the study of the flow of energy through nature. • Within a system energy cannot be re-used.

1 st Law of Thermodynamics • States that energy can be transferred and transformed, but it CANNOT be created nor destroyed. • Law of Conservation of • Energy of the universe Energy. is constant.

2 nd Law of Thermodynamics • States that every transformation results in a reduction of the FREE ENERGY (useable energy). • Energy transfers and transformations increase ENTROPY (disorder, randomness or chaos). • Law of Entropy. • Energy always tends to go from a more usable (higher quality) form to a less usable (lower quality) form.

• Any conversion is less than 100% efficient and therefore some energy is lost or wasted. • Usually this energy is lost in the form of HEAT (= random energy of molecular movement). (photosynthesis) Waste heat Mechanical energy Chemical energy (food) Chemical energy Solar energy Waste heat (moving, thinking, living) Waste heat

Only 25% of chemical “E” stored in gasoline is transformed in to motion of the car and 75% is lost as heat!!

Without adding energy to a system, the system will break down.