biosphere

ecosystem

community

population

Studying organisms in their environment

organism

Essential questions• What limits the production in ecosystems?

• How do nutrients move in the ecosystem?

• How does energy move through the ecosystem?

Ecosystem• All the organisms in a community plus abiotic

factors– Transform energy & process matter

• Ecosystems are self-sustaining– what is needed?

capture energy transfer energy cycle nutrients

capture energy transfer energy cycle nutrients

biosphere

Ecosystem inputs

constant inputof energy

energy flowsthrough

nutrients cycle

Nutrientscycle

inputs energy nutrients

inputs energy nutrients

Don’t forgetthe laws of

Physics!

Matter cannotbe created or

destroyed

Generalized Nutrient cycling

Decompositionconnects all

trophic levels

Lakes

Runoff

Percolation in soil

Evaporation

Transpiration

Precipitation

Oceans

Solar energy

AquiferGroundwater

Water cycle

Water vapor

abiotic reservoir: surface & atmospheric

waterenter food chain: precipitation & plant

uptakerecycle: transpiration

return to abiotic: evaporation & runoff

abiotic reservoir: surface & atmospheric

waterenter food chain: precipitation & plant

uptakerecycle: transpiration

return to abiotic: evaporation & runoff

Breaking the water cycle• Deforestation breaks the water

cycle– groundwater is not transpired.

Precipitation is not created.

forest desert

desertification

Repairing the damage• The Greenbelt Movement

– planting trees in Kenya

– restoring a sustainable ecosystem

– establishing democracy

– empowering women

Wangari MaathaiNobel Peace prize 2004Nobel Peace prize 2004

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

abiotic reservoir: N in atmosphere

enter food chain: nitrogen fixation by

soil & aquatic bacteriarecycle: decomposing &

nitrifying bacteriareturn to abiotic: denitrifying bacteria

abiotic reservoir: N in atmosphere

enter food chain: nitrogen fixation by

soil & aquatic bacteriarecycle: decomposing &

nitrifying bacteriareturn to abiotic: denitrifying bacteria

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

abiotic reservoir: rocks, minerals, soil

enter food chain: erosion releases

soluble phosphate uptake by plants

recycle: decomposing bacteria

& fungireturn to abiotic: loss to ocean

sediment

abiotic reservoir: rocks, minerals, soil

enter food chain: erosion releases

soluble phosphate uptake by plants

recycle: decomposing bacteria

& fungireturn to abiotic: loss to ocean

sediment

Phosphorus cycle

CO2 inatmosphere

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

abiotic reservoir: CO2 in atmosphere

enter food chain: photosynthesis =

carbon fixation in Calvin cycle

recycle: decomposition

return to abiotic: respiration combustion

abiotic reservoir: CO2 in atmosphere

enter food chain: photosynthesis =

carbon fixation in Calvin cycle

recycle: decomposition

return to abiotic: respiration combustion

Carbon cycle

Carbon Cycle

Most of the carbon on earth is locked up in the crust in limestone rocks: CaCO3

Some of the rest is in fossil fuels: coal, crude oil and natural gas.

Coal = carbonMethane = CH4

Some is in the atmosphere as CO2

A lot is dissolved in seawater as carbonate (CO32-),

bicarbonate (HCO3-), carbonic acid (H2CO3) and carbon dioxide

(CO2)

And of course some is in living & dead biological tissue (Biomass)

PHOTOSYNTHESIS (plants and Algae):6CO2 + 6H2O C6H12O6 + 6O2

(sunlight)

Where:C6H12O6 = sugarO2 = oxygenCO2 = carbon dioxideH2O = water

RESPIRATION (all life)C6H12O6 + 6O2 6CO2 + 6H2O (+ energy!)

Carbon Cycle getting started…

CO2

CO2

LimestoneCaCO3

Photosynthesis:

CO 2 + H 2

O sugar + O 2

Respiration:

Sugar + O 2

CO 2 + H 2

O

The main thing is to present it as a CYCLE

That means every place with carbon has at least one arrow coming in and one arrow going out!