Moving Energy and Nutrients Through Ecosystems

Abiotic factors• The non-living parts of the environment,

including the climate determine what can live where.

• Temperature• Available water• Soil type• Light Intensity• Wind• pH

Biotic Factors

• Include all the organisms as well as how they interact with the abiotic factors.– Examples of interactions?

Ecosystems (without humans)

• Consist of Biotic (Organisms) and Abiotic factors

• BOTH move energy through the ecosystem

• How is energy moved?

Organisms

• Producers– Convert environmental energy to carbon

bonds

• Consumers– Get energy from carbon bonds

• Herbivores• Carnivores• Omnivores• Detritivores (Decomposers)

Energy Flow Through the Ecosystem

A more biological view:

• Arrows show how energy flows - producer to consumer.

Energy Does NOT recycle!

• When we “use” food, we are actually breaking bonds between carbon atoms.

• This releases energy which can be used by an organism OR can be lost as heat.

• LOOK back at the diagram. What is the source of energy used by organisms?

Inorganic Nutrients

• Do NOT contain C-C bonds.

• Include:– Phosphorus (bones, teeth, cellular

membranes– Nitrogen (from protein)

– Water and CO2 (products of cellular respiration)

How Do Inorganic Nutrients Travel?

• Autotrophs take inorganic nutrients from the environmental reservoir and incorporate into molecules.– Generally from the soil or water surrounding the

autotroph

• Heterotrophs consume autotrophs and acquire the inorganic nutrients.– When organisms die, they become detritus (food

for decomposers)

• Decomposers return inorganics into the soil, water and air.

Summary

• The ultimate source of energy is _______• All energy is ultimately lost as _________• Energy is passed from organism to

organism through _____________• ___________ remove the last energy from

the remains of the organism (detritus)• _____________ nutrients are cycled but

_______________ is not.

Biogeochemical Cycles

• Inorganic nutrients can cycle through organisms, land, air, and water

• Inorganic nutrients are CHEMICALS (molecules) that CYCLE through BIOlogical and GEOlogical world

Terms to know

• Reservoir – parts of a cycle where a chemical is held for a long time

• Exchange pools – parts of a cycle where a chemical is held for a short time

• Residence time – length of time held in either a reservoir or an exchange pool.

Reservoir or exchange pool?

• Ocean

• Cloud

• Water movement through a plant

• Consumed food

• Rock

Four important cycles

• Water

• Carbon (and oxygen)

• Nitrogen

• Phosphorus

Carbon Cycle

The carbon cycle

CO2 inAtmosphere

CO2 in Ocean

Nitrogen Cycle

The nitrogen cycle

N2 in Atmosphere

NH3

NO3-

and NO2-

Phosphorus Cycle

The take home message:

• How does energy move?

• How do inorganic nutrients move?