1. KEY CONCEPT Matter cycles in and out of an ecosystem.

2. Water cycles through the environment.
The Hydrologic or water cycle is the circular pathway of water on Earth. 70% of Earth is water.
Organisms all have bodies made mostly of water.
60-70% Human Body composition
precipitation
condensation
transpiration
evaporation
water storage
in ocean
surface
runoff
lake
groundwater
seepage

3. Elements essential for life also cycle through ecosystems.
A biogeochemical cycle is the movement of a particular chemical through the biological (living) and geological (nonliving) parts of an ecosystem.
Ex. Oxygen, carbon, nitrogen, or phosphorus
96% human body is composed of oxygen, carbon, nitrogen, and hydrogren.

4. The main processes involved in the oxygen cycle are photosynthesis and respiration.
Oxygen cycles indirectly through an ecosystem by the cycling of other nutrients such as carbon dioxide.
oxygen
respiration
carbon
dioxide
photosynthesis

5. Carbon is emitted by the burning of fossil fuels.
Carbon is the building block of life.Needed to form carbonhydrates, proteins, fats, and Nucleic Acids.
The carbon cycle moves carbon from the atmosphere, through the food web, and returns to the atmosphere.
Carbon is emitted by the burning of fossil fuels.
Some carbon is stored for long periods of time in areas called carbon sinks.
Ex. Forest
(cellulose in wood)
fossil fuels
photosynthesis
carbon dioxide
dissolved in water
decomposition
of organisms
respiration
carbon
dioxide
in air
combustion

6. The nitrogen cycle mostly takes place underground.
Some bacteria convert gaseous nitrogen (N2) into ammonia (NH3) through a process called nitrogen fixation. 78% of air
Some nitrogen-fixing
bacteria live in nodules
on the roots of plants
such as Legumes.
Others live freely in the soil or aquatic
Environments
Convert Gaseous
Nitrogen into Ammonia (NH3)
nitrogen in
atmosphere
animals
denitrifying
bacteria
nitrifying
ammonium
ammonification
decomposers
plant
nitrogen-fixing
bacteria in soil
bacteria in roots
nitrates
nitrites

7. Nitrifying bacteria change the ammonium (NH4+) into nitrate (NO3-).
Ammonia released into the soil is transformed into ammonium when added with Hydrogen ions (H+) in acidic soil.
Nitrifying bacteria change the ammonium (NH4+) into nitrate (NO3-).
Nitrogen moves through
the food web and returns to the soil during decomposition.
Plants take up
Nitrogen to make
amino acids and
proteins.
nitrogen in
atmosphere
animals
denitrifying
bacteria
nitrifying
ammonium
ammonification
decomposers
plant
nitrogen-fixing
bacteria in soil
bacteria in roots
nitrates
nitrites

8. Phosphate is released by the weathering of rocks.
The phosphorus cycle takes place at and below ground level. Does not occur in the atmosphere. Needed for ATP, bones, teeth, etc.
Phosphate is released by the weathering of rocks.
Phosphorus moves through the food web and returns to the soil during decomposition.
geologic uplifting
rain
weathering of
phosphate from rocks
runoff
sedimentation
forms new rocks
leaching
phosphate in solution
animals
plants
decomposers
phosphate
in soil
Phosphorus leaches into groundwater from the soil and is locked in sediments.
Both mining and agriculture add phosphorus into the environment.