Ecology

• What does Ecology study

  The relationship between living and non-living environment
• Biosphere

  Narrow area around the globe that can support life

  10 km up in the atmosphere to 10 km down in the ocean
• Atmosphere


  All the gases
• Hydrosphere 


  All the water (solid and liquid)
• Lithosphere (aka Geosphere) 


  All the soil and rock
• Biotic 


  living

  can be found in all 3 zones
• Abiotic 


  non-living

  can be found in all 3 zones
• System 


  A set of parts that all function together to perform a task
• Open system


  allows both energy and matter to enter and exit freely

  Ex. Forest
• Closed System 


  Energy can come in and out freely but matter in finite and must be recycled

  Ex. Earth
• How much energy do we get from the sun?

  99%
• Where does the other 1% of energy come from

  geothermal and tidal
• Albedo Effect 


  Reflectivity of a surface

  high albedo = high reflectivity
• 30% of energy is reflected back into space
• 18% of energy is absorbed by gases

  (drives the H2O cycle and therefor weather)
• 50% of energy heats up the earths surface
• 1-2% of energy is captured by pants for photosynthesis
• Once the suns energy comes into the biosphere only plants can use it to make food > Producers (Autotrophs) through photosynthesis
• consumers > Herbivore (eats producers)

  consumers > Carnivore (eats herbivores)

  consumers > carnivore (eats other carnivores)
• Decomposers are also consumers and can be found at any feeding level (omnivores)
• Trophic level


  The position of an organism in a food chain
• Laws of thermodynamics


  1st Law - Energy cannot be created or destroyed it can only be transformed or transferred
• 2nd law of thermodynamics

  No transfer/ transformation of energy is ever 100% efficient (some energy is always lost)
• Rule of 10


  As we move through trophic levels in a food chain, only 10% of the energy from one level is passed in to the next
• Why the loss of energy?

  Organisms consume energy for metabolic activities, moving, reproduction, warmth…
• Pyramid of Biomass


  Biomass is the amount of living tissue of all the organisms found at a particular trophic level
• Pyramid of Energy


  measures the energy transfer from one trophic level to the next

  Due to the rule of 10 this pyramid is never inverted
• Sometimes pyramids can be used to show human impact on a food chain
• Once organic materials are locked up in sinks (living organisms, debris, rock layers, ocean sediment) they must be returned to the cycles via either slow or rapid cycling
• Rapid Cycling 


  Relatively quicker

  Materials returned to cycles via:

  Waste deposition

  Decomposition

  Cellular respiration
• Slow Cylcing


  Much slower

  Materials returned to cycles via:

  Burning of fossil fuels

  volcanic eruptions

  mining

  geological uplifting
• The role of H2O

  H2O is fundamental to the cycling of mater > transports nutrients (C, N, P, S…), it is a solvent in many reactions, and it is a reactant in photosynthesis thus essential to life
• Parts of the H2O Cycle

  1. Evaporation/ Transportation
  2. Water storage in the atmosphere
  3. Condensation
  4. Precipitation
  5. Infiltration into soil
  6. Run off
  7. Water storage in both hydrosphere (lakes, rivers) and lithosphere (glaciers)
• Oxygen 


  21% of our atmosphere

  photosynthesizers produce O2 as a waste product
• Carbon 


  In the atmosphere as CO2 and CH4 (methane)

  In organisms, carbon is part of carbs, proteins, and lipids in tissues

  Returned to atmosphere through both rapid and slow cycling
• Greenhouse effect 


  Natural occurence that is necessary for life on Earth. Greenhouse gases are like CO2, methane and H2O vapour creat a blanket that traps the suns rays (heat) in the atmosphere > keeps the temp of the Earth ideal for living things
• The Sulfur Cycle

  • Major component of proteins and vitamins
  • Plants absorb sulfur in its water soluble form SO4 (sulfate), incorporate it into their tissues
  • Animals get sulfur by consuming other organisms
  • Decomposers return sulfur to the soil or to the air as H2S (hydrogen sulfide > rotten egg gas)
  • If the sulfur becomes part of the sediment then it enters slow cycling. Ex. mining, erosion, burning fosil fuels
• The Nitrogen Cycle

  • Nitrogen is needed for proteins and nucleic acids (DNA/RNA)
  • 78% of the earths atmosphere
  • Plants use nitrogen in its H2O soluble form NO2 and NO3 > Soil bacteria converts it for plants
• Why do homeowners aerate their lawns in Spring?

  Denitrifying bacteria like anaerobic conditions.

  By introducing O2 into the soil, denitrification stops therefore nitrogen remains in the soil and feeds the lawn
• The Phosphorus Cycle

  • Needed for DNA/RNA and ATP
  • Does not circulate through the atmosphere
  • Found in the soil and rock sediments and it enters cycling through weathering/ erosion and H2O run off
  • As it mixes with H2O, it becomes PO4 (phosphate) and it gets absorbed by plants
  • Returned to the sediment via waste decomposition