Ecology Chapter 2

The Nonliving Environment

Cycles of Matter

•      What is the law of conservation of matter?

•      All mass is recycled in nature

•      Earth has a finite amount of matter

Water Cycle

Water Use

Nitrogen Cycle

The Carbon Cycle

Converting Energy

•      What is the law of conservation of energy?

•      All mass is transferred in nature

•      Most energy starts with the sun and then ends up as heat

Converting Energy

•      Photosynthesis (process in which plants convert solar energy to chemical energy) requires carbon dioxide.

•          - carbon dioxide + water + (solar energy) --> oxygen + food (sugar)

•       Respiration (process in which organisms convert chemical energy in food into mechanical energy)  requires oxygen

•          - food(sugar) + oxygen --> carbon dioxide + water + (mechanical energy)

 

Converting Energy

•      Some organisms perform chemosynthesis, which is the production of energy-rich nutrient molecules from chemicals.

–    Done instead of photosynthesis

–    Generally done by animals that live near hydrothermal vents

 

Respiration

Energy Transfer

•      Law of conservation of energy - energy cannot be created or destroyed, only transferred

•      Organisms transfer energy to each other through feeding relationships

Energy Transfer

•      A food chain is a way of showing how matter and energy pass from one organisms to another

–   A diagram                                                  showing what                                                 eats what

Energy Transfer

•      A food web is a model that shows all the possible feeding relationships among the organisms in a community

–   Combination of food                                     chains in an ecosystem

Energy Pyramids

•      Food chains rarely have more than five links

–   Why?

•      The amount of energy available is reduced as you move from one level to the next in a food chain.

–   Organisms use some energy to live

–   Much of energy is converted to heat

•      10% Rule - organisms only get about 10% of the energy from an organism they eat

Energy Pyramids

•      An energy pyramid shows the amount of energy available at each feeding level in an ecosystem

•      The bottom layer of the pyramid (producers) is the largest

•      As you move up the pyramid, each level becomes smaller (by about 10%)