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