Ecosystems Types and Human Impacts. Ecosystems l Biomes and their Distribution –Biome - a terrestrial region with characteristic types of natural, undisturbed

EcosystemsEcosystems

Types and Human ImpactsTypes and Human Impacts


Biomes and their DistributionBiomes and their Distribution– Biome - a terrestrial region with Biome - a terrestrial region with

characteristic types of natural, characteristic types of natural, undisturbed plant communities adapted undisturbed plant communities adapted to the climate of an areato the climate of an area


Biomes and their DistributionBiomes and their Distribution– Climate - condition of the atmosphere Climate - condition of the atmosphere

over a long period of time in a over a long period of time in a geographic localegeographic locale


Biomes and their DistributionBiomes and their Distribution– Climatic FactorsClimatic Factors» Temperature (MAT)Temperature (MAT)» Precipitation (MAP)Precipitation (MAP)

The limiting factor in determining the type and The limiting factor in determining the type and distribution of biome(s)distribution of biome(s)

Effects of Earth’s Tilted AxisEffects of Earth’s Tilted Axis

Global Air CirculationGlobal Air Circulation

Convective Heat Transfer in AtmosphereConvective Heat Transfer in Atmosphere

Global Air Circulation and BiomesGlobal Air Circulation and Biomes

Hadley CellsHadley Cells


Desert BiomesDesert Biomes– Desert - an area where evaporation Desert - an area where evaporation

exceeds precipitation and in which MAP exceeds precipitation and in which MAP < 10 inches< 10 inches

MAT and MAP in the Desert BiomeMAT and MAP in the Desert Biome


Desert BiomesDesert Biomes– TypesTypes» Tropical Desert Tropical Desert

Southern Sahara Southern Sahara High year-round temperaturesHigh year-round temperatures Little variation in MAT and MAPLittle variation in MAT and MAP


Desert BiomesDesert Biomes– TypesTypes» Temperate Desert Temperate Desert

MojaveMojave High daytime summer temperaturesHigh daytime summer temperatures Cold daytime winter temperaturesCold daytime winter temperatures Higher MAP than tropical desertsHigher MAP than tropical deserts


Desert BiomesDesert Biomes– TypesTypes» Polar Desert Polar Desert

Gobi Gobi Cold winters; warm summersCold winters; warm summers Low MAP Low MAP


Desert BiomesDesert Biomes– Survival StrategiesSurvival Strategies» PlantsPlants

Needle-type leaves with wax coatings (creosote)Needle-type leaves with wax coatings (creosote) Deep tap roots (mesquite)Deep tap roots (mesquite) Fleshy stems and shallow root systems (cacti)Fleshy stems and shallow root systems (cacti) Store biomass in seeds during dry periodsStore biomass in seeds during dry periods


Desert BiomesDesert Biomes– Human ImpactsHuman Impacts» Livestock overgrazingLivestock overgrazing» Off-road activitiesOff-road activities» Rapid urban growthRapid urban growth» Irrigation - salinizationIrrigation - salinization» Groundwater depletionGroundwater depletion


Grassland BiomesGrassland Biomes– Grassland - areas where MAP is Grassland - areas where MAP is

sufficient to support grasses and small sufficient to support grasses and small plants, but not enough to support large plants, but not enough to support large stands of treesstands of trees

MAT and MAP in the Grassland BiomeMAT and MAP in the Grassland Biome


Grassland BiomesGrassland Biomes– TypesTypes» Tropical Grasslands Tropical Grasslands

High MATHigh MAT Low-moderate MAPLow-moderate MAP Prolonged dry seasonProlonged dry season


Grassland BiomesGrassland Biomes– TypesTypes» Tropical Grasslands Tropical Grasslands

SavannaSavanna– Deciduous shrubs and small treesDeciduous shrubs and small trees– Two prolonged dry spellsTwo prolonged dry spells– Grazers (e.g. Wildebeests)Grazers (e.g. Wildebeests)– Browsers (e.g. Giraffes)Browsers (e.g. Giraffes)


Grassland BiomesGrassland Biomes– TypesTypes» Temperate Grasslands Temperate Grasslands

Cold wintersCold winters Hot, dry summersHot, dry summers Drought and fireDrought and fire Deep, nutrient-rich soilsDeep, nutrient-rich soils Thick, intertwined root systemsThick, intertwined root systems Agricultural Agricultural breadbasketbreadbasket


Grassland BiomesGrassland Biomes– TypesTypes» Temperate Grasslands Temperate Grasslands

North America -tNorth America -tall-grass, short-grass prairiesall-grass, short-grass prairies South America - South America - pampaspampas Africa- vAfrica- veldteldt Europe/Asia - steppeEurope/Asia - steppe


Grassland BiomesGrassland Biomes– TypesTypes» Polar Grasslands (Tundra)Polar Grasslands (Tundra)

Low MAT and MAPLow MAT and MAP Most precipitation falls as snowMost precipitation falls as snow Long, dark wintersLong, dark winters PermafrostPermafrost Spongy mat of grasses, mosses, shrubsSpongy mat of grasses, mosses, shrubs Most plant growth occurs in 6-8 week summerMost plant growth occurs in 6-8 week summer Bogs and marshes form when permafrost meltsBogs and marshes form when permafrost melts


Grassland BiomesGrassland Biomes– Human ImpactsHuman Impacts» Conversion to agricultural landConversion to agricultural land

Releases COReleases CO22

Soil erosionSoil erosion

» Overgrazing and soil compactionOvergrazing and soil compaction» Oil exploration in tundraOil exploration in tundra


Forest BiomesForest Biomes– ForestForest - - areas where MAP is sufficient areas where MAP is sufficient

to support growth of various species of to support growth of various species of tress and smaller forms of vegetationtress and smaller forms of vegetation

MAT and MAP in the Forest BiomeMAT and MAP in the Forest Biome


Forest BiomesForest Biomes– TypesTypes» Tropical Rain Forests Tropical Rain Forests

High MAP and MATHigh MAP and MAT Evergreen broadleafsEvergreen broadleafs Leaves have large surface areas to maximize Leaves have large surface areas to maximize

photosynthesisphotosynthesis


Forest BiomesForest Biomes– TypesTypes» Tropical Rain Forests Tropical Rain Forests

Soil nutrient level is limiting factorSoil nutrient level is limiting factor High biodiversityHigh biodiversity Stratification of plant and animal niches to Stratification of plant and animal niches to

minimize interspecific competitionminimize interspecific competition


Forest BiomesForest Biomes– TypesTypes» Temperate Deciduous ForestsTemperate Deciduous Forests

Long, warm summersLong, warm summers Cold wintersCold winters Abundant precipitation that is evenly distributed Abundant precipitation that is evenly distributed Broadleaf deciduous treesBroadleaf deciduous trees

– OakOak– MapleMaple– HickoryHickory


Forest BiomesForest Biomes– TypesTypes» Temperate Deciduous ForestsTemperate Deciduous Forests

Drop leaves in fall to survive winter temperaturesDrop leaves in fall to survive winter temperatures Thick litter layer on forest floorThick litter layer on forest floor


Forest BiomesForest Biomes– TypesTypes» Polar Evergreen Coniferous Forests Polar Evergreen Coniferous Forests

(Taigas)(Taigas) Long, cold, dry wintersLong, cold, dry winters Little sunlightLittle sunlight Short summersShort summers


Forest BiomesForest Biomes– TypesTypes» Evergreen Coniferous Forests (Taigas)Evergreen Coniferous Forests (Taigas)

Spruce, Pine, HemlockSpruce, Pine, Hemlock Needle-shaped leaves with waxy coatings to Needle-shaped leaves with waxy coatings to

withstand intense winter cold and droughtwithstand intense winter cold and drought Low plant diversityLow plant diversity


Grassland BiomesGrassland Biomes– Human ImpactsHuman Impacts» Clearing for agriculture, urban growth, Clearing for agriculture, urban growth,

export logging, grazingexport logging, grazing Soil erosionSoil erosion Plant nutrient depletionPlant nutrient depletion Water pollutionWater pollution Loss of biodiversityLoss of biodiversity


Grassland BiomesGrassland Biomes– Human ImpactsHuman Impacts» Clearing of temperature deciduous forests Clearing of temperature deciduous forests

for timber, agriculture, urban developmentfor timber, agriculture, urban development > 99% original stands have been cleared> 99% original stands have been cleared


Aquatic EcosystemsAquatic Ecosystems– Classified based on salinityClassified based on salinity

»FreshwaterFreshwater»MarineMarine


Aquatic Life ZonesAquatic Life Zones– Benefits of living in aquatic Benefits of living in aquatic

environmentsenvironments» Buoyancy provides physical supportBuoyancy provides physical support» Limited temperature fluctuationsLimited temperature fluctuations» Abundant nutrientsAbundant nutrients


Aquatic Life ZonesAquatic Life Zones– Marine EcosystemsMarine Ecosystems» Open OceanOpen Ocean» Coastal ZoneCoastal Zone


Aquatic Life ZonesAquatic Life Zones– Marine EcosystemsMarine Ecosystems» Open OceanOpen Ocean

Regulates Earth’s climateRegulates Earth’s climate– Distribution of heat in currentsDistribution of heat in currents– Evaporation - Hydrologic CycleEvaporation - Hydrologic Cycle

Reservoir for COReservoir for CO22

Habitat for > 250,000 species of plants and Habitat for > 250,000 species of plants and animalsanimals


Aquatic Life ZonesAquatic Life Zones– Marine EcosystemsMarine Ecosystems» Coastal ZoneCoastal Zone

Warm, nutrient-rich watersWarm, nutrient-rich waters Contains > 90% of marine speciesContains > 90% of marine species High NPPHigh NPP



Estuary - partially-enclosed area where seawater Estuary - partially-enclosed area where seawater mixes with fresh water (brackish water)mixes with fresh water (brackish water)

Coastal WetlandsCoastal Wetlands– Habitat for waterfowlHabitat for waterfowl– Remove toxic chemicals, sediment, nutrientsRemove toxic chemicals, sediment, nutrients– Absorb and store floodwaters Absorb and store floodwaters



Mangrove swampsMangrove swamps– Found along warm, tropical coastsFound along warm, tropical coasts– Salt-tolerant mangrove treesSalt-tolerant mangrove trees– Protect shoreline from erosionProtect shoreline from erosion



Rocky Shorelines (Pacific Northwest, USA)Rocky Shorelines (Pacific Northwest, USA) Sandy Shorelines (Gulf Coast)Sandy Shorelines (Gulf Coast) Barrier Islands(Atlantic Coast; Gulf Coast)Barrier Islands(Atlantic Coast; Gulf Coast)

– Thin offshore islands parallel to shorelineThin offshore islands parallel to shoreline– Protect mainland from erosionProtect mainland from erosion– Atlantic City, Miami Beach Atlantic City, Miami Beach



Coral ReefsCoral Reefs– ““Rainforests” of the oceanRainforests” of the ocean– Polyps - soft-bodied organisms that secrete a Polyps - soft-bodied organisms that secrete a

protective shell of calcium carbonateprotective shell of calcium carbonate– Mutualistic relationship between Mutualistic relationship between

photosynthetic algae and polypsphotosynthetic algae and polyps


Aquatic Life ZonesAquatic Life Zones– Marine EcosystemsMarine Ecosystems» Human ImpactsHuman Impacts

Open OceanOpen Ocean– DumpingDumping– Oil drillingOil drilling



Coastal ZonesCoastal Zones– DevelopmentDevelopment– Dredging and filling of wetlands Dredging and filling of wetlands – Discharge of raw sewage and heavy metals in Discharge of raw sewage and heavy metals in

estuariesestuaries



Coastal ZonesCoastal Zones– Cutting of mangroves for timberCutting of mangroves for timber– Coral reef destructionCoral reef destruction


Aquatic Life ZonesAquatic Life Zones– Freshwater EcosystemsFreshwater Ecosystems» Lake - large, natural body of standing fresh Lake - large, natural body of standing fresh

waterwater OriginsOrigins

– Glaciers (Lake Michigan)Glaciers (Lake Michigan)– Depressions in lithosphere Depressions in lithosphere – Volcanic activity (Crater Lake, Oregon)Volcanic activity (Crater Lake, Oregon)– Dams (every lake in Texas!)Dams (every lake in Texas!)


Aquatic Life ZonesAquatic Life Zones– Freshwater EcosystemsFreshwater Ecosystems» LakesLakes

Classified based on nutrient content and NPPClassified based on nutrient content and NPP– OligotrophicOligotrophic– EutrophicEutrophic

Temperate Zone LakesTemperate Zone Lakes

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Ecosystems Types and Human Impacts. Ecosystems l Biomes and their Distribution –Biome - a terrestrial region with characteristic types of natural, undisturbed