1. Nutrient Cycles in Ecosytems

2. Review - Energy Flow Energy enters ecosystems as sunlight.
Review - Energy Flow
Energy enters ecosystems as sunlight.
Some of the energy is absorbed and stored by autotrophs.
It is gradually used as it moves up trophic levels.
Eventually all energy will be changed to other forms which cannot be passed on.
So, energy is NOT recycled through an ecosystem.
The Earth gets a constant flow of sunlight to it. And light and heat radiates out.
But, nutrients (matter) do not enter or leave the Earth. So, they must be recycled through ecosystems.

3. The most common (95%) ATOMS found in most organisms are:
OXYGEN
CARBON
HYDROGEN
NITROGEN
The same molecules are passed around
again and again within the biosphere in
___________________________
BIOGEOCHEMICAL CYCLES

4. The 4 main cycles! p. 1196 The water cycle (H2O)
The nitrogen cycle (N)
The Phosphorous Cycle (P)
The carbon cycle (C)

5. WATER CYCLE - water is essential to life!

6. WATER CYCLE 1. What is the biological importance of water?
2. What forms of water are available to life?
3. What are the main reservoirs of water?
4. What are the key processes?
Evaporation Transpiration Precipitation Runoff
Groundwater

7. 9 NITROGEN CYCLE NH3 NO3- and NO2- N2 in Atmosphere Section 3-3
BIOLOGY; Miller and Levine; Prentice Hall; 2006

8. NITROGEN CYCLE 1. What is the biological importance of nitrogen?
2. What forms of nitrogen are available to life?
3. What are the main reservoirs of nitrogen?
4. What are the key processes?
Atmospheric nitrogen Assimilation Fertilizers
Decomposition Nitrogen fixing
Denitrifying

9. Image from: Pearson Education Inc; Publishing as Pearson Prentice Hall
PHOSPHORUS CYCLE

10. 7 CARBON CYCLE CO2 in ocean
BIOLOGY; Miller and Levine; Prentice Hall; 2006

11. CARBON CYCLE 1. What is the biological importance of carbon?
2. What forms of carbon are available to life?
3. What are the main reservoirs of carbon?
4. What are the key processes?
Combustion Photosynthesis Respiration Decomposition
Fossil fuels Volcanoes Burning Forests

12. The importance of biogeochemical cycles is:
The main point:
The importance of biogeochemical cycles is:
To make available nutrients that living organisms need to survive.
copyright cmassengale

13. Who recycle nutrients? Decomposers!
Detritivores - ingest parts of dead plants or animals (e.g. earthworms, insects).
Saprotrophs - absorb organic molecules (e.g. fungi, bacteria).

14. Carbon Cycle Draw and label a diagram of the carbon cycle. Include:
photosynthesis
respiration of autotrophs
respiration of heterotrophs
fossil fuels
combustion
dissolving in oceans
burning forests
volcanoes

15. Analyze the changes in concentration of atmospheric carbon dioxide.

16. CLOSURE
What is the main difference between energy flow in an ecosystem, and nutrient flow in an ecosystem?