energy in an ecosystem for your warm-up, answer these… where is energy in an ecosystem? where does...
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Energy in an Ecosystem
For your warm-up, answer these…
Where is energy in an ecosystem?Where does it come from initially?Where does it go to / end up?What form is it in?
You have 3 minutes – tick – tock – tick – tock
Organisms cannot exist without matter & energy
• All living things are made of water.
• All living things are made of the same matter as non-living things (carbon, hydrogen, nitrogen, phosphorus).
• All living things use energy (cell theory).
Biotic and abiotic factors are
interdependentLiving factors depend on non-living
factors as a source of nutrients. Non-living factors depend on living
factors to cycle matter.
Energy is transferred not recycled!
Energy Transfer = Food Chain
SUN AUTOTROPHS
HERBIVORES CARNIVORES
Trophic Level# of energy transfers from sun to organism
(i.e. each step in a food chain)
TROPHIC LEVELS IN A CHAIN
• 1st trophic level is the producer
• 2nd trophic level is the primary consumer or herbivore
• 3rd level is the secondary consumer or carnivore
• 4th level is the tertiary consumer or carnivore feeding on other carnivores.
FOOD WEB
a network of
connected food chains
Energy Flow is Inefficient
Energy stored as fat (~17%)
E lost as HEAT (~48%)
Organic Wastes (~35%)
So…10% Law
Only 10% of energy from previous trophic level is available to next level as
food or biomass.
Pyramid of EnergyPYRAMID OF ENERGY
BIOMASS amount of energy converted to mass of living tissue that
can be used by the next trophic level.
PYRAMID OF NUMBERS
CYCLEGEO
CHEMICAL
BIO
Matter is cycled! Molecules are simply
rearranged as they are made and broken
down.
Water Cycle• Precipitation/Condensation
• Absorption (roots, groundwater/soil, plant leaves)
• Transpiration (through stomata in plant leaves).
• Evaporation (heat)
Carbon Cycle• CO2 absorbed by plants• Carbohydrate made
(glucose)• Death and decomposition• Fossil fuels (combustion)
releases C into atmosphere.
Nitrogen Cycle• Assimilation - N from
atmosphere is gained by soil through nitrogen fixation by bacteria.
• Ammonification (from excretory wastes).
• Denitrification converts NH3 back to N2.
