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

2. Elements essential for life also cycle through ecosystems.
A biogeochemical cycle is the movement of a particular chemical through the biological and geological parts of an ecosystem.

3. The hydrologic, or water cycle is the circular pathway of water on Earth from the atmosphere, to the surface, below ground, and back
Evaporation
Cloud formation
Precipitation
Transpiration (loss of H2O from plants)
Condensation
Runoff

4. Hydrologic Cycle
Precipitation: rain or snow falls to ground
Water seeps into ground, ponds, streams, swamps, wetlands, lakes, etc.
Empty into oceans
Evaporation: water reenters atmosphere
Transpiration: water vapor released by plants
Condensation: water vapor in atmosphere creates clouds

5. oxygen photosynthesis respiration carbon dioxide
Oxygen cycles indirectly through an ecosystem by the cycling of other nutrients.
oxygen
respiration
carbon
dioxide
photosynthesis

6. Oxygen Cycle
Plants release oxygen as waste during photosynthesis
Animals breathe in oxygen
Animals release carbon dioxide during cellular respiration
Plants take in carbon dioxide

7. Carbon is the building block of life.
The carbon cycle moves carbon from the atmosphere, through the food web, and returns to the atmosphere.
Carbon Dioxide in air
Burning of
Fossil fuels
Photo-
synthesis
Carbon
Dissolved
In water
respiration
decomposition

8. Carbon Cycle
Plants use energy from the sun to convert carbon dioxide into sugar that become part of the plant’s structure
Moves to animals as they eat plants and as one organism eats another
Carbon is returned to the atmosphere by:
1. respiration
2. decomposition of dead organisms
3. Burning of fossil fuels and wood
4. Emissions from factories/cars
5. Methane emission from wetlands/landfills/livestock

9. The nitrogen cycle mostly takes place underground.
nitrogen in
atmosphere
animals
denitrifying
bacteria
nitrifying
ammonium
ammonification
decomposers
plant
nitrogen-fixing
bacteria in soil
bacteria in roots
nitrates
nitrites

10. Nitrogen Cycle
Bacteria turns gaseous nitrogen into ammonia
Ammonia released into the soil is transformed into ammonium by materials in the soil
Nitrifying bacteria change the ammonium into nitrate
Nitrate is taken up by plants
Plants convert the nitrate into amino acids and proteins
Nitrogen moves through the food web as animals eat plants and/or other animals
Nitrogen returned to soil as decomposers break down animal excretions or dead animals
Denitrifying bacteria use nitrate as an oxygen source, releasing nitrogen gas into the atmosphere as a waste product

11. 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