How Ecosystems WorkHow Ecosystems Work

Chapter 5Chapter 5

Energy flow in the Energy flow in the EcosystemEcosystem

• Life depends on the sun in a process Life depends on the sun in a process called photosynthesiscalled photosynthesis

• Plants, algae and some bacteria Plants, algae and some bacteria capture solar energy and with Carbon capture solar energy and with Carbon Dioxide CODioxide CO22 and Water H and Water H22O make O make Oxygen OOxygen O22 and sugar or glucose and sugar or glucose CC66HH1212OO66

• 6CO6CO22 + 6H + 6H22O + sun = CO + sun = C66HH1212OO66 + 6O + 6O22

• All organisms ultimately get their All organisms ultimately get their energy from the sunenergy from the sun

•Begins with the Begins with the SUNSUN

•PhotosynthesisPhotosynthesis

6CO2 + 6H2O + sunlight & chlorophyll C6H12O6 + 6O2

Energy Flow Through an Ecosystem

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Producers Producers use use most of the most of the energy they energy they

makemake for for themselves.themselves.

PRODUCERSOrganisms Organisms that can that can make make glucose glucose during during photosyntphotosynthesis are hesis are calledcalled

The The energy that is not energy that is not used by producersused by producers

can be passed on to can be passed on to organisms that organisms that

cannot make their cannot make their own energy.own energy.

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Organisms that Organisms that cannot make their cannot make their

own energyown energy

CONSUMERCONSUMERSS

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Most of the Most of the energy is used energy is used

by the consumer by the consumer but somebut some of the of the energy moves energy moves

into the into the atmosphere as atmosphere as

heat.heat.

Consumers Consumers eat eat producersproducers to to get energy:get energy:

Herbivores- eat plantsOmnivores – eat Plants and animalsCarnivores – eat animals

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An Exception to the Rule:An Exception to the Rule:

• Deep Ocean EcosystemsDeep Ocean Ecosystems

• Hydrothermal VentHydrothermal Vent

• Bacteria use Hydrogen Bacteria use Hydrogen

Sulfide from the hot Sulfide from the hot

water to make their water to make their

own foodown food

• Thus they are producers!Thus they are producers!http://www.naturalhistorymag.com

DecomposersDecomposersBreaks down deadBreaks down dead

organisms in an organisms in an ecosystemecosystem

and returns and returns

nutrients to nutrients to

soil, water and soil, water and airair

Bacteria and FungiBacteria and Fungi

http://soils.usda.gov/sqi/concepts/soi

Cellular Cellular RespirationRespiration

Burning the FuelBurning the Fuel

CELLULAR CELLULAR RESPIRATION RESPIRATION is the is the chemical reaction chemical reaction that releases the that releases the energy in glucoseenergy in glucose

Excess energy is Excess energy is stored as fatstored as fat

6O2 + C6H12O6 -->> 6H2O + 6CO2 + energy

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Food Webs:Food Webs:•Are Are

interconnecteinterconnected food chainsd food chains

•They show the They show the feeding feeding relationships relationships in an in an ecosystemecosystem

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FOOD CHAIN – shows the FOOD CHAIN – shows the transfer of energytransfer of energy from the from the sunsun to to producerproducer to primary to primary consumer then to higher consumer then to higher

order order consumersconsumers

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Food Chains Show Food Chains Show Available EnergyAvailable Energy

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TrophicLevels

Energy Energy PyramidPyramid

• Amount of available Amount of available energy energy decreasesdecreases for for higher consumershigher consumers

• Amount of available Amount of available energy energy decreasesdecreases down down the food chainthe food chain

• It takes a It takes a large number large number of producersof producers to support a to support a small number of primary small number of primary consumersconsumers

• It takes a It takes a large number large number of primary consumersof primary consumers to to support a small number support a small number of secondary consumersof secondary consumershttp://sps.k12.ar.us/massengale/biology

Envi Sci 1/19/11Envi Sci 1/19/11

• Stamp then go over food Stamp then go over food chain/web worksheetchain/web worksheet

• Case Study page 130-131Case Study page 130-131

• Finish up notes…Finish up notes…

• Tomorrow Library. Biome Tomorrow Library. Biome Project!!Project!!

Carbon CycleCarbon Cycle

• Cycled between the atmosphere, land, Cycled between the atmosphere, land, water and organismswater and organisms

• Carbon is the basic building block for all Carbon is the basic building block for all living organismsliving organisms

• It is moved through the atmosphere by It is moved through the atmosphere by plants/animals in COplants/animals in CO22/O/O22 exchange exchange through breathing and photosynthesisthrough breathing and photosynthesis

• Large carbon deposits exist in the oceans Large carbon deposits exist in the oceans and soil from dead organisms in the form and soil from dead organisms in the form of carbonates or carbon sinks of limestoneof carbonates or carbon sinks of limestone

The Cycling of Materials

How Humans Affect the Carbon How Humans Affect the Carbon CycleCycle• When we burn fossil fuels we release When we burn fossil fuels we release

carbon into the atmospherecarbon into the atmosphere• In 2000 1/3 of all carbon dioxide emitted In 2000 1/3 of all carbon dioxide emitted

in the US was from motor vehiclesin the US was from motor vehicles• 6 Billion metric tons of carbon a year 6 Billion metric tons of carbon a year

released as COreleased as CO22 into the atmosphere into the atmosphere• 50% of this remains in the atmosphere 50% of this remains in the atmosphere

which contributes to global warmingwhich contributes to global warming• 1 Billion metric tons of CO1 Billion metric tons of CO22 are dissolved are dissolved

into the ocean – carbon sinkinto the ocean – carbon sink• Plants absorb the remaining COPlants absorb the remaining CO22

Carbon Cycle

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Nitrogen CycleNitrogen Cycle• Although the atmosphere is Although the atmosphere is

78% organisms cannot utilize 78% organisms cannot utilize nitrogen in that form nitrogen in that form

• Nitrogen Fixing Bacteria – Nitrogen Fixing Bacteria – alter the Nitrogen to make it alter the Nitrogen to make it usable for all organismsusable for all organisms

• This bacteria lives on nodules This bacteria lives on nodules of rootsof roots

• Nitrogen is essential for plant Nitrogen is essential for plant growth, obtained through soilgrowth, obtained through soil

• Nitrogen can be found in all Nitrogen can be found in all waste products of animalswaste products of animals

Nitrogen Cycle

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Phosphorous CyclePhosphorous Cycle

• Phosphorous is stored in rocks and soilPhosphorous is stored in rocks and soil

• Phosphorous is then moved through Phosphorous is then moved through the rock and water cycle the rock and water cycle

• Plants and animals take in Plants and animals take in phosphorousphosphorous

Phosphorous Cycle

http://www.ikzm-d.de/abbildungen/59_phosphoruscycle.gif

Acid PrecipitationAcid Precipitation

• When fuel is burned, large amounts of When fuel is burned, large amounts of nitric oxide is release into the nitric oxide is release into the atmosphere.atmosphere.

• In the air, nitric oxide can combine with In the air, nitric oxide can combine with oxygen and water vapor to form nitric oxygen and water vapor to form nitric acid.acid.

• Dissolved in rain or snow, the nitric acid Dissolved in rain or snow, the nitric acid falls as acid precipitation.falls as acid precipitation.

Fertilizers and the Nitrogen Fertilizers and the Nitrogen and Phosphorus Cyclesand Phosphorus Cycles

• Excess fertilizer causes excess Excess fertilizer causes excess nitrogen and phosphorus can cause nitrogen and phosphorus can cause rapid growth of algae.rapid growth of algae.

• Excess algae can deplete an aquatic Excess algae can deplete an aquatic ecosystem of important nutrients ecosystem of important nutrients such as oxygen, on which fish and such as oxygen, on which fish and other aquatic organisms depend.other aquatic organisms depend.

• Ecological successionEcological succession is a gradual is a gradual process of change and replacement of process of change and replacement of the types of species in a community.the types of species in a community.

• Primary succession Primary succession is a type of is a type of succession that occurs on a surface succession that occurs on a surface where no ecosystem existed beforewhere no ecosystem existed before

• Secondary succession Secondary succession occurs on a occurs on a surface where an ecosystem has surface where an ecosystem has previously existed. can occur in previously existed. can occur in ecosystems that have been disturbed ecosystems that have been disturbed or disrupted by humans, animals, or or disrupted by humans, animals, or by natural process such as storms, by natural process such as storms, floods, earthquakes, or volcanic floods, earthquakes, or volcanic eruptions.eruptions.

• A A pioneer speciespioneer species is a species that is a species that colonizes an uninhabited area and colonizes an uninhabited area and that starts an ecological cycle in that starts an ecological cycle in which many other species become which many other species become establishedestablished

• A A climax communityclimax community is the final, is the final, stable community in equilibrium with stable community in equilibrium with the environment.the environment.

Ecological Ecological SuccessionSuccession

Succession CollageSuccession Collage•Create a scenario:Create a scenario:

–Primary Succession – initial growth Primary Succession – initial growth (new volcano, island, receding (new volcano, island, receding sea)sea)

–Secondary Succession – calamity, Secondary Succession – calamity, disaster natural or man madedisaster natural or man made

•Cut out pictures of your area to Cut out pictures of your area to represent each stage of successionrepresent each stage of succession

•Describe each stage and give a Describe each stage and give a rationale for itrationale for it

Ecological SuccessionEcological Succession• Primary succession can occur Primary succession can occur

• on new islands created by volcanic eruptionson new islands created by volcanic eruptions• in areas exposed when a glacier retreatsin areas exposed when a glacier retreats• any other surface that has not previously any other surface that has not previously

supported lifesupported life• Primary succession is much slower than Primary succession is much slower than

secondary succession. This is because it secondary succession. This is because it begins where there is no soil.begins where there is no soil.

• The first pioneer species to colonize bare The first pioneer species to colonize bare rock will probably be bacteria and lichens, rock will probably be bacteria and lichens, which can live without soil. which can live without soil.

• The growth of lichens breaks down the The growth of lichens breaks down the rock, which with the action of water, rock, which with the action of water, begins to form soil.begins to form soil.