1. Part I: Nitrogen and Phosphorus
Cycles
Part I: Nitrogen and Phosphorus

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

3. Elements essential for life cycle through ecosystems.
A biogeochemical cycle is the movement of a particular chemical through the biological and geological parts of an ecosystem.
Incl. Water, Oxygen, Carbon, Nitrogen, & Phosphorus

4. The Phosphorus Cycle
The element phosphorus (P)is released in the form of ionic phosphate (PO43-)
Weathering of rock, mining, some detergents and fertilizers
Phosphate is taken up by plants and fungi
Consumers absorb phosphate from plants
Decomposers return phosphate to soil
Phosphate leaches into water supply
May form new phosphate containing rock

5. The phosphorus cycle takes place at and below ground level.
Phosphate is released by the weathering of rocks.
Phosphorus moves through the food web and returns to the soil during decomposition.
Phosphorus leaches into groundwater from the soil and is locked in sediments.
Both mining and agriculture add phosphorus into the environment.
geologic uplifting
rain
weathering of
phosphate from rocks
runoff
sedimentation
forms new rocks
leaching
phosphate in solution
animals
plants
decomposers
phosphate
in soil

7. The Nitrogen Cycle Bacteria fix nitrogen from the air
Consumers and producers incorporate nitrogen into their tissues
Nitrogen can be fixed industrially from the air
Production of ammonia
Decay processes return nitrogen to the air
Nitrogen from fertilizers may contaminate water sources

8. The nitrogen cycle mostly takes place underground.
Some bacteria convert gaseous nitrogen into ammonia through a process called nitrogen fixation.
Some nitrogen-fixing bacteria live in nodules on the roots of plants; others live freely in the soil.
nitrogen in
atmosphere
animals
denitrifying
bacteria
nitrifying
ammonium
ammonification
decomposers
plant
nitrogen-fixing
bacteria in soil
bacteria in roots
nitrates
nitrites

9. Ammonia released into the soil is transformed into ammonium.
Nitrifying bacteria change the ammonium into nitrate.
Nitrogen moves through the food web and 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

11. Aquarium Nitrogen Cycle