ch 18b biosphere

8/6/2019 Ch 18b Biosphere

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The BiosphereThe Biosphere


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OutlineOutline

Climate and the BiosphereClimate and the Biosphere Terrestrial CommunitiesTerrestrial CommunitiesAquatic CommunitiesAquatic Communities

Life ZonesLife Zones LakesLakes

EstuariesEstuaries

SeashoresSeashores OceansOceans


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Effectof Solar RadiationEffectof Solar Radiation

Distribution of solar energy due to aDistribution of solar energy due to a

spherical planetand the rotation and path ofspherical planetand the rotation and path ofthe Earth around the sun affecthow thethe Earth around the sun affecthow thewind blows and the amountof rainfallwind blows and the amountof rainfallvarious regions receive.various regions receive.


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Formation of a Rain ShadowFormation of a Rain Shadow


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Terrestrial CommunitiesTerrestrial Communities

Biome has aBiome has a particular mix of plants,particular mix of plants,animals and other organismsanimals and other organisms adapted toadapted to

living under certain environmental conditions.living under certain environmental conditions. Often delineated by climate.Often delineated by climate.

Temperature and precipitation varies according to latitudeTemperature and precipitation varies according to latitudeand altitude.and altitude.


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Biome DistributionBiome Distribution


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Climate and BiomesClimate and Biomes


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TundraTundra

Arctic tundra encircles Earth justsouth of iceArctic tundra encircles Earth justsouth of ice--

covered polar seas in Nor

thern Hemisphere.covered po

lar seas in Nor

thern Hemisphere. Covers 20% of Earths land surface.Covers 20% of Earths land surface.

Trees are not found in the tundra because growingTrees are not found in the tundra because growingseason is too short.season is too short.

Roots cannotpenetrate permafrost.Roots cannotpenetrate permafrost.


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TundraTundra


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Coniferous ForestsConiferous Forests

TaigaTaiga typifies coniferous forestwith conetypifies coniferous forestwith cone--bearing trees.bearing trees.

Trees we ll adapted to cold.Trees well adapted to cold. Leaves and bark have thick covering.Leaves and bark have thick covering.

NeedleNeedle--like leaves can withstand weightof heavylike leaves can withstand weightof heavysnowfall.snowfall.

Temperate RainforestTemperate Rainforest (Old(Old--Growth Forests)Growth Forests)of Pacific Northwest.of Pacific Northwest.

Evergreen forest.Evergreen forest.


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Temperate Deciduous ForestsTemperate Deciduous Forests

Found south oftaiga in eastern NorthFound south oftaiga in eastern NorthAmerica, eastern Asia, and much ofAmerica, eastern Asia, and much of

Europe.Europe. Well defined season with long growingWell defined season with long growing

seasons.seasons.

Tallesttrees form a canopy.Tallesttrees form a canopy. GroundGround--life is plentiful.life is plentiful.


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Temperate Deciduous ForestTemperate Deciduous Forest


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TropicalForestsTropicalForests

Found in equatorial regions.Found in equatorial regions. Plentiful rainfall.Plentiful rainfall.

Mostanimals live in trees.Mostanimals live in trees.Abundant insectlife.Abundant insectlife.

Epiphytes grow in many areas.Epiphytes grow in many areas.

Soils are nutrientSoils are nutrient--poor.poor.

Rapid recycling of nutrients.Rapid recycling of nutrients. Swidden agriculture successful butdestructive.Swidden agriculture successful butdestructive.


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GrasslandsGrasslands

Grasslands occur where annual rainfall isGrasslands occur where annual rainfall isgreater than 25 cm, butgenerallygreater than 25 cm, butgenerally

insufficientto supporttrees.insufficientto supporttrees. Grasses well adapted to changingGrasses well adapted to changing

environment.environment.

Temperate GrasslandsTemperate Grasslands SavannasSavannas


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Temperate GrasslandTemperate Grassland


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SavannaSavanna


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DesertsDeserts

Usually found atlatitudes of about30Usually found atlatitudes of about30oo ininboth north and south hemispheres.both north and south hemispheres.

Descending winds lack moisture.Descending winds lack moisture.Annual rainfallless than 25 cm.Annual rainfallless than 25 cm.

Large temperature differential between dayLarge temperature differential between day

and night.and night.


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DesertsDeserts


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Aquatic CommunitiesAquatic Communities

LakesLakes Bodies of water classified by their nutrientBodies of water classified by their nutrient

status.status. OligotrophicOligotrophic -- NutrientNutrient--poor.poor. EutrophicEutrophic -- NutrientNutrient--rich.rich.

Lake StratificationLake Stratification

In temperate zones, deep lakes are stratified in theIn temperate zones, deep lakes are stratified in thesummer and winter.summer and winter.


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Life ZonesLife Zones Plankton are importantcommunityPlankton are importantcommunity

components in fresh water and saltwater.components in fresh water and saltwater.

PhytoplanktonPhytoplankton -- AlgaeAlgae

ZooplanktonZooplankton -- AnimalsAnimals Life ZonesLife Zones

Littoral zone:Littoral zone: Closestto shore.Closestto shore.

Limnetic zone:Limnetic zone: Sunlitareas.Sunlitareas. Profundal zone:Profundal zone: Below lightpenetration.Below lightpenetration.

Benthic zone:Benthic zone: SoilSoil--Water interface.Water interface.


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Zones of a LakeZones of a Lake


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Coastal CommunitiesCoastal Communities

EstuariesEstuaries Partially enclosed bodies of water where freshPartially enclosed bodies of water where fresh

water and seawater meetand mix.water and seawater meetand mix. Organisms mustbe able to adaptto changingOrganisms mustbe able to adaptto changing

salinity.salinity.

Estimated over half of all marine fishes develop inEstimated over half of all marine fishes develop in

protective environmentof estuaries.protective environmentof estuaries.


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Estuary Structure and FunctionEstuary Structure and Function


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SeacoastsSeacoasts


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OceansOceans

Major ocean currents move heat from theMajor ocean currents move heat from theequator to cooler parts ofthe biosphere.equator to cooler parts ofthe biosphere.

Gulf Stream warms eastcoastof NorthGulf Stream warms eastcoastof NorthAmerica and parts of Europe.America and parts of Europe.

El Nino Southern OscillationEl Nino Southern Oscillation

Cold upwelling off westcoastof South AmericaCold upwelling off westcoastof South Americasubsides.subsides.


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Ocean CurrentsOcean Currents


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ch 18b biosphere

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