Organization of Ecosystem

1
Organization of Ecosystem

• Two principal concepts
• Flow of Energy
• Cycling of Matter

2
Energy Flow Cycling of Matter
3
Flow of Energy

• The earth receives about one one-billionth of the
  of the suns energy output. Describe the
  relative portions of this energy reflected, used
  to power physical processes, and available for
  living processes (lecture).

4
Solar Energy

• 28 reflected by atmosphere sea surface,
• 71 powers physical processes
• heating soil, air, water
• wind,
• ocean currents,
• evaporation, etc.
• lt 1 trapped by photosynthesis (available to
  life).

5
Input to Ecosystem light E. via Photosynthesis

• CO2 H2O light ? sugar O2
• Occurs in plants, algae (producers)
• Energy (potential) stored in covalent bonds of
  sugar molecules.
• Movement (Flow) from organism to organism by
  feeding.

6
Transfer of Energy by Aerobic Respiration

• C6H12O6 (sugar) O2 ? CO2 H2O energy (work
  lost heat)
• Occurs in animals (consumers, some detritivores)
• Occurs in bacteria, fungi (decomposers
  detritivores)

7
Trophic levels

• Food chain
• Tertiary consumer (higher carnivores)
• Secondary consumers (carnivores)
• Primary consumers (herbivores)
• Producers (plant)
• Decomposer/detritivore

8
Trophic levels

• Food web
• Tertiary consumer (higher carnivores)
• Secondary consumers (carnivores)
• Primary consumers (herbivores)
• Producers (plants, algae, cyanobacteria)
• Decomposers/detritivores

9
Apply Laws of Thermodynamics

• 1. Energy can be transferred and transformed.
• 2. At transfer/transformation energy lost
• (low grade heat/infrared radiation to space).

10
Trophic levelsPyramid of Energy

• 10 J
• 100 J
• 1000 J
• 10,000 J

11
Trophic levelsPyramid of Numbers

• 10 tertiary consumers
• 130 secondary consumers
• 2000 primary consumers
• 50,00 producers

12
Trophic levelsPyramid of Biomass

• 25 g/ hectare
• 250 g/ hectare
• 2500 g/ hectare
• 25000 g/ hectare
• 4 kcal/gram biomass

13
Cycling of Matter

• Producers take up matter
• Photosynthesis
• CO2 from air H2O from water/soil ? glucose
  O2
• Movement of matter through ecosystem
• Return of matter to inorganic form
• Aerobic respiration
• glucose O2 ? CO2 to air H2O to water/air
• Reservoirs/stores of matter

14
Carbon cycle

• Fluxes
• Photosynthesis
• Respiration decomposition
• Reservoirs
• Atmosphere
• Oceans
• Fossil fuels
• Carbonate rocks

15
Hydrologic cycle

• Fluxes
• Precipitation
• Evaporation
• Transpiration
• Reservoirs
• Atmosphere
• Oceans
• Groundwater

16
Nitrogen cycle

• Fluxes
• Nitrogen fixation
• Denitrification
• Weathering erosion
• Reservoirs
• Atmosphere
• Rock soil
• Organisms