Cycles of Matter

Matter cycles in and out of an

ecosystem.

What is a cycle?

continuously repeating event

or process

2 Types of Cycles • Hydrologic Cycle: also known as the water

cycle, is the circular pathway of water on Earth.

• Biogeochemical Cycle: is the movement of a particular chemical through the biological and geological parts of an ecosystem. – 4 Biogeochemical Cycles:

• Oxygen Cycle

• Carbon Cycle

• Nitrogen Cycle

• Phosphorus Cycle

Hydrologic Cycle (aka The Water Cycle)

Water cycles from the

atmosphere, to Earth’s surface, below ground

and back.

Hydrologic Cycle

precipitation

condensation

transpiration

evaporation

water storage

in ocean

surface

runoff

groundwater

lake

Rain, snow, sleet or hail

Gas changing to a liquid

Evaporation of water from plant leaves

Gas changing to a liquid

Liquid changing to

a gas

Biogeochemical Cycle: The Oxygen Cycle

• The main processes involved in the oxygen cycle are photosynthesis and respiration.

Biogeochemical Cycle: The Oxygen Cycle

• Oxygen flows into the atmosphere as a byproduct of photosynthesis.

• Organisms breath in the oxygen and then release it as carbon dioxide through respiration.

oxygen

respiration

carbon

dioxide

photosynthesis

Biogeochemical Cycle: The Carbon Cycle

• Carbon is the building block of life because ALL living things are made of carbon molecules.

• The 4 carbon-based molecules:

– Carbohydrates

– Lipids

– Proteins

– Nucleic acids

Biogeochemical Cycle: The Carbon Cycle

• Carbon can be found in solid, liquid and gaseous states.

• Sources of carbon include: – CO2 (Carbon dioxide) in the

atmosphere

– Fossil fuels (underground deposits of oil, natural gas and coal)

– Dead organic matter in the soil

Biogeochemical Cycle: The Carbon Cycle

• The carbon cycle

moves carbon

from the

atmosphere,

through the food

web, and returns

to the

atmosphere.

carbon

dioxide

in air

photosynthesis

combustion

respiration

photosynthesis

carbon dioxide

dissolved in water

fossil fuels

decomposition

of organisms

respiration

Biogeochemical Cycle: The Nitrogen Cycle

• Nitrogen is found in proteins and nucleic acids.

• Our breathable air contains about 78% nitrogen in the form of nitrogen gas (N2).

Biogeochemical Cycle: The Nitrogen Cycle

• Takes place mostly underground

• The nitrogen cycle is the pathway for the movement of nitrogen among Earth’s living organisms, waters, rocks and minerals, and atmosphere.

• Some bacteria convert gaseous nitrogen into ammonia through a process called nitrogen fixation.

– Ammonia is a form of nitrogen that is easily absorbed by the roots of plants.

• In low oxygen conditions, bacteria convert ammonia back to N2 for use in the atmosphere in a process known as denitrification.

Biogeochemical Cycle: The Nitrogen Cycle

Biogeochemical Cycle: The Phosphorus Cycle

• Takes place at and below ground level

• One of the slowest biogeochemical cycles

• Phosphorus can be found in water, soils and rocks.

– Phosphate is released by the weathering of rocks.

– Phosphorus moves through the food web and returns to the soil during decomposition.

Biogeochemical Cycle: The Phosphorus Cycle

rain geologic uplifting

weathering of

phosphate from rocks

runoff

phosphate in solution

leaching

phosphate

in soil

animals

plants

decomposers sedimentation

forms new rocks