Nutrient CyclesNutrient Cycles

Water Cycle

Water Cycle

• Circulate fresh water between the atmosphere and the earth

• Ensures that the supply of water is replenished

Basic steps of the water cycle

1. Precipitation falls into lakes, water, ocean and runoff

2. Sun provides energy to heat water up3. EVAPORATION Water evaporates due to the

heat (water vapor)

Basic steps of the water cycle

4. TRANSPORATION from plants send water vapor in the air

5. RESPIRATION from people and animals 6. The water vapor is then moved by wind and

ocean currents

Basic steps of the water cycle

7. CONDENSATION Water cools to form clouds8. Clouds become saturated with water vapor and

become PRECIPTATION

Carbon Cycle

Carbon Cycle

• Cycling of carbon between carbon dioxide and organic molecules

Basic Steps of the Carbon Cycle

1. Plants use CO2 and energy to perform photosynthesis

2. Animals eat plants and CO2 pass through their tissues

3. Carbon returns to the earth through respiration, excretion or decomposition

4. Some carbon returns to the earth through the burning of fossil fuels– The fossil fuels come from organisms the did not

decompose but are buried

Nitrogen Cycle

• Transforms nitrogen into ammonia, nitrite and finally nitrate so it can be used by organisms

• Changing of nitrogen between inorganic and organic states

Nitrogen Cycle

Nitrogen Cycle

• Increases the amount of usable nitrogen in soil– Important because plants use nitrate to synthesize

nucleic acids and proteins

• Nitrogen fixation is occurring– The conversion of nitrogen gas into nitrate by

several types of bacteria (NITROGEN FIXERS)

Steps of the Nitrogen Cycle

1. Nitrogen is converted into ammonia (NH3) by nitrogen fixers

2. The nitrogen fixers convert ammonia into nitrite (NO2)

3. Nitrite is converted into nitrate (NO3)4. Organisms eat plants that have nitrate5. Decomposers release ammonia as they break down

plant and animal remains6. Bacteria converts waste from organisms to nitrogen

gas

Phosphorous Cycle

Phosphorous Cycle

• important in cycling of phosphorus because it only exists as part of an organism, dissolved in water or an element in a rock

Steps of the Phosphorous cycle

1. Phosphates (PO4) introduced into the soil from weathering, or breakdown of sedimentary rocks.

2. Plants & fungi absorb phosphate ions from the soil

3. Animals consume plants or fungi4. Phosphorous returns to soil as waste or

decomposed material.

Nutrient CycleNutrient Cycle

Page 203-206 In the EOCT Workbook

Page 82 (Textbook)