ecosystems and energy flow. energy transfer primary producers primary producers the trophic level...
TRANSCRIPT
Ecosystems and Energy Flow
Energy Transfer Primary producers
• the trophic level that supports all others
• autotrophs Primary consumers
• herbivores Secondary/ tertiary/
quaternary consumers• carnivores
Detrivores/decomposers• special consumers that derive
nutrition from non-living organic matter
Decomposers
Break down/recycle organic matter
Fungi Bacteria Some
invertebrates (worms, etc)
Productivity Primary productivity- amount of light energy converted to chemical
energy by autotrophs• Gross (GPP): total energy • Net (NPP): represents the storage of energy available to consumers
• R: energy used for respiration
NPP = GPP - R Biomass: primary productivity reflected as dry weight of organic
material Secondary productivity: the rate at which an ecosystem's
consumers convert chemical energy of the food they eat into their own new biomass
Global NPP
Energy Flow Ecological efficiency
• % of E transferred from one trophic level to the next (10%)
Pyramid of productivity• multiplicative loss of
energy in trophic levels Biomass pyramid
• trophic representation of biomass in ecosystems
Pyramid of numbers• trophic representation of
the number of organisms in an ecosystem
• Follows “rule of 10”
Chemical Cycling
Biogeochemical cycles: the various nutrient circuits, which involve both abiotic and biotic components of an ecosystem• Water• Carbon• Nitrogen• Phosphorus
Pollution Water pollution
• Sewage/agricultural runoff• Excess nitrogen causes eutrophication
algal blooms kill fish• Creates “dead zones”
Air pollution• Burning of wood, coal,
chemicals, fossil fuels, etc.• Smog
respiratory problems• Acid precipitation
crop damage structural damage to
buildings/statues
Biological Magnification
Trophic process in which retained substances become more concentrated at higher levels• Buildup of toxins in
predatory fish• DDT Causes egg shells of
predatory birds to become fragile
Greenhouse Effect Warming of planet due to
atmospheric accumulation of carbon dioxide• Burning of fossil fuels• Deforestation
CO2 traps heat from sunlight like a greenhouse
Results in • Increased ocean temps
death of coral reefs• Increased global temps
melting of polar ice caps/ raised ocean levels/changes in weather patterns
Ozone Depletion Effect of chlorofluorocarbons
(CFC’s) released into the atmosphere• Takes ~50 years for results
to be seen after release of CFC’s (ie. the worst is yet to come)
Depletion of ozone increased UV rays skin cancer, crop damage, etc.