AP Biology Ecosystems
AP Biologybiosphere
ecosystem
community
population
Studying organisms in their environment
organism
AP Biology
Essential questions! What limits the production in ecosystems?
! How do nutrients move through theecosystem?
! How are humans disrupting the biosphere?
AP Biology
Ecosystem! All the organisms in a community plus abiotic
factors" ecosystems are transformers of energy
& processors of matter
! Ecosystems are self-sustaining" what is needed?
! capture energy! transfer energy! cycle nutrients
AP Biologybiosphere
Ecosystem inputs
constant inputof energy
energy flowsthrough
nutrients cycle
nutrients can only
cycle
inputs! energy! nutrients
Don’t forgetthe laws of Physics!
Matter cannotbe created or
destroyed
AP Biology
consumers
decomposers
abioticreservoir
nutrientsmade availableto producers
geologicprocesses
Nutrientcycling
consumers
consumers
producers
decomposers
abioticreservoir
nutrientsmade availableto producers
geologicprocesses
Decompositionconnects all
trophic levels
AP Biology
Carbon cycleCO2 in
atmosphere
Diffusion RespirationPhotosynthesis
Photosynthesis
Plants and algae
PlantsAnimals
Industry and home
Combustion of fuels
Animals
Carbonates in sediment
Bicarbonates
Deposition ofdead material
Depositionof deadmaterial
Fossil fuels(oil, gas, coal)
Dissolved CO2
AP Biology
Birds
Herbivores
Plants
amino acids
CarnivoresAtmospheric
nitrogen
loss to deep sediments
Fish
Plankton withnitrogen-fixingbacteria
Nitrogen-fixingbacteria
(plant roots)
Nitrogen-fixingbacteria
(soil)
Denitrifyingbacteria
Death, excretion, feces
Nitrifying bacteria
soil nitrates
excretion
Decomposing bacteria
Ammonifying bacteria
Nitrogen cycle
AP Biology
Phosphorus cycle
Loss to deep sediment
Rocks andminerals
Soluble soilphosphate
Plants andalgae
Plants Urine
Land animals
Precipitates
Aquaticanimals
Animal tissueand feces
Animal tissueand feces
Decomposers(bacteria and
fungi)
Decomposers(bacteria & fungi)
Phosphatesin solution
Loss indrainage
AP Biology
Lakes
Runoff
Percolation in soil
Evaporation
Transpiration
Precipitation
Oceans
Solar energy
AquiferGroundwater
Water cycle
Water vapor
AP Biology
Breaking the water cycle! Deforestation breaks the water cycle
" groundwater is not transpired to theatmosphere, so precipitation is notcreated
forest → desert
AP BiologyWangari Maathai
Repairing the damage! The Greenbelt Movement
" planting trees in Kenya
" restoring a sustainable ecosystem
" establishing democracy
" empowering women
Nobel Peace prize 2004
AP Biology
Effects of deforestationC
on
cen
trat
ion
of
nit
rate
(m
g/l
)
1965 1966Year
2
0
4
40
80
1967 1968
Deforestation
nitrate levels
40% increase in runoff" loss of water
! 60x loss in nitrogen
! 10x loss in calcium
loss into surface water
AP Biology
Energy flows through ecosystems
sun
producers (plants)
loss of energy
loss of energy
secondary consumers(carnivores)
primary consumers(herbivores)
AP Biology
! Feeding relationships" start with energy
from the sun
" 1st level of all foodchains is plants
" most food chainsusually go uponly 4 or 5 levels
" all levels connect todecomposers
Food chains
Fungi
Level 4
Level 3
Level 2
Level 1
Decomposers
Producer
Primary consumer
Secondary consumer
Tertiary consumer
top carnivore
carnivore
herbivore
Sun
Bacteria
AP Biology
Food webs
! Food chains arelinked together intofood webs
! Who eats whom?" a species may
weave into web atmore than one level! bears! humans
# eating meat?# eating plants?
AP BiologyTertiary
consumerPrimary
consumerPrimary producer
Secondaryconsumer
Trophic structure! Food chains
" feeding relationships" food chain usually 4 or 5 links
! trophic levels
" length of food chain limited byinefficiency of energy transfer! how much energy lost from one level to next
sun
AP Biology
Energy transfer! Loss of energy between levels of food chain
" To where is the energy lost? The cost of living!
only this energymoves on to the
next level in the food chain
17%growth
50%waste (feces)
33%cellularrespiration
energy lost todaily living
energy lost todaily living
sun
AP Biology
Ecological pyramid! Loss of energy between levels of food chain
" can feed fewer animals in each level
1,000,000,000
100,000
100
1
Numbers
sun
Humans in food chains! Dynamics of energy through ecosystems have
important implications for human populations" how much energy does it take to feed a human?
! if we are meat eaters?! if we are vegetarian?
AP Biology
Nutrients & trophic levels! Energy flows through
but nutrients cycle
" must be recycled to beavailable for the nextgeneration
" decomposers returnnutrients to the soilafter creatures die! fungi
! bacteria
nutrients
decomposers
Top Related