Topic G.2

Highest energy is in the producers who get their energy from the sun (NOT!!!!). Make that sunlight!

What happens to the energy as it is passed from one trophic level to the next? 80-95% is lost as heat or used by the organism in that trophic level for maintenance.

Energy in excreted waste is transferred to decomposers as is energy in bodies of dead organisms

Units should be kJm-2yr-1

Gross production – the total amount of energy trapped in the organic matter produced by plants per area per time (kJ)

Net production – gross production minus energy lost in respiration (the cellular type!)

Gross – respiration = net production

Biomass – the dry weight of an organism measured in gm-2yr-1

Use the information at the bottom of page 565 to create a pyramid of energy.

After completing the pyramid, check the top of page 566 to be sure you included all relevant items.

See page 566This similar to the pyramid of

energy (pg. 563) and a pyramid of numbers (how many of each organism are present)

gm-2

The change in abiotic and biotic factors in an ecosystem over time.

Seen when one species replaces another in an area

Two types:Primarysecondary

Occurs on previously barren areas such as a new volcanic island

Typically there is no soil presentLichens are pioneer plants which

breakdown rock. Also, as they die they contribute to a thin layer of soil.

Moss usually follows lichensAs time goes on seeds are brought to

the area in bird droppings or by the sea

An area is recolonized following a natural or artificial disaster.

Some soil is presentSeeds and roots may be present as

well

Describe succession on a glacial moraine.

See chart on page 568

Includes storms, fires, floods, volcanoes

What type of disturbances are common inTerrestrial environmentsLakes streams, pondsMarine environmentsVolcanic islands

Not all disturbance is negative.Ex.) Yellowstone fires

Increase amount of organic matter due to plant and animal death and decay

Soil depth increases as organic matter builds up

Plant roots reduce erosionAddition of humus (organic matter),

improves soil quality and allows it to hold moisture as well as aerate

Mineral recycling takes place