1. SECTION 13.5 : Biogeochemical Cycles
Hydrologic cycle (water cycle)
Carbon cycle
Nitrogen cycle
Phosphorus Cycle
In an ecosystem, material is constantly cycled among organisms and the environment.
Most food & oxygen is produced by primary producers through photosynthesis
Energy is not cycled in the biosphere

2. Precipitation -- Groundwater Condensation -- Evaporation
1. Hydrologic cycle
Vocabulary:
Precipitation -- Groundwater
Condensation Evaporation
Transpiration Aquifers
precipitation
condensation
transpiration
evaporation
water storage
in ocean
surface
runoff
lake
groundwater
seepage

3. Photosynthesis -- Cell. Respiration Combustion -- Decomposition
2. Carbon cycle
Vocabulary:
Photosynthesis -- Cell. Respiration
Combustion -- Decomposition
Fossil Fuels
fossil fuels
photosynthesis
carbon dioxide
dissolved in water
decomposition
of organisms
respiration
carbon
dioxide
in air
combustion

4. Nitrogen fixing bacteria convert nitrogen gas (N) into ammonia (NH3)
3. Nitrogen cycle
Nitrogen fixation:
Nitrogen fixing bacteria convert nitrogen gas (N) into ammonia (NH3)
These bacteria on the roots of plants or in the soil.
Legumes are a
special kind of
vegetable plant
-decomposers
are important
to this process
nitrogen in
atmosphere
animals
denitrifying
bacteria
nitrifying
ammonium
ammonification
decomposers
plant
nitrogen-fixing
bacteria in soil
bacteria in roots
nitrates
nitrites

5. Nitrogen is taken in by plants/animals to make protein & nucleotides.
(Ammonification)
Nitrogen returns to the soil during decomposition.
nitrogen in
atmosphere
animals
denitrifying
bacteria
nitrifying
ammonium
ammonification
decomposers
plant
nitrogen-fixing
bacteria in soil
bacteria in roots
nitrates
nitrites

6. Phosphate is released by the weathering of rocks.
4. Phosphorus cycle
Phosphate is released by the weathering of rocks.
P moves into plants (producers) and then into consumers.
P returns to the soil during decomposition.
P flows from the soil into groundwater and is trapped in rocks.
geologic uplifting
rain
weathering of
phosphate from rocks
runoff
sedimentation
forms new rocks
leaching
phosphate in solution
animals
plants
decomposers
phosphate
in soil