major ecosystems/biomes of the world. earth’s major biomes o biome a large, relatively distinct...
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Major Ecosystems/Biomes of the Major Ecosystems/Biomes of the WorldWorld
Earth’s Major BiomesEarth’s Major Biomes
o BiomeBiome• A large, relatively distinct terrestrial region with a A large, relatively distinct terrestrial region with a
similar climate soil, plants, and animals, regardless similar climate soil, plants, and animals, regardless of where it occurs in the worldof where it occurs in the world
• Nine major biomes Nine major biomes
o Location of each biome is Location of each biome is primarily determined by:primarily determined by:• Temperature (varies with both latitude and Temperature (varies with both latitude and
elevation)elevation)• PrecipitationPrecipitation
o Biomes can also be defined byBiomes can also be defined by• Winds, rapid temperature changes, fires, floods, Winds, rapid temperature changes, fires, floods,
etc.etc.
Vertical ZonationVertical Zonation
o Increasing Increasing in elevation in elevation has similar has similar effect on effect on
ecosystem ecosystem as traveling as traveling
to higher to higher latitudeslatitudes
Tropical RainforestTropical Rainforesto Lush, species-rich Lush, species-rich
biome that occurs biome that occurs where climate is where climate is warm and moist warm and moist throughout the yearthroughout the year
o PrecipitationPrecipitation• 200-450 cm/yr200-450 cm/yr
o Very productive Very productive biomebiome
o Most species-rich Most species-rich biomebiome
Tropical RainforestTropical Rainforesto Ancient, weathered, Ancient, weathered,
nutrient-poor soilnutrient-poor soil• Nutrients tied up in Nutrients tied up in
vegetation, not soilvegetation, not soil
o VegetationVegetation• 3 distinct canopy 3 distinct canopy
layerslayers
o AnimalsAnimals• Most abundant insect, Most abundant insect,
reptiles and reptiles and amphibians on earthamphibians on earth
DesertsDesertso Biome where lack of Biome where lack of
precipitation limits precipitation limits plant growthplant growth
o TemperatureTemperature• Can very greatly in Can very greatly in
24-hr period, as well 24-hr period, as well as yearly (based on as yearly (based on location)location)
o PrecipitationPrecipitation• < 25 cm/yr< 25 cm/yr
DesertsDesertso Soils low in nutrients, high in saltsSoils low in nutrients, high in saltso Vegetation sparseVegetation sparse
• cactus and sagebrushcactus and sagebrusho Animals are very small to regulate Animals are very small to regulate
temperaturetemperatureSonoran Desert
Temperature Temperature Deciduous ForestsDeciduous Forests
o Forest biome that occurs Forest biome that occurs in temperate areas with in temperate areas with a moderate amount of a moderate amount of precipitationprecipitation
o PrecipitationPrecipitation• 75-150 cm/yr75-150 cm/yr
o TemperatureTemperature• SeasonalitySeasonality• Hot summers and cold Hot summers and cold
winterswinters
Temperate Deciduous Temperate Deciduous ForestForest
o Topsoil is rich in organic material and Topsoil is rich in organic material and underlain by clayunderlain by clay
o Vegetation is primarily Vegetation is primarily deciduousdeciduous• Oak, maple, beechOak, maple, beech
o AnimalsAnimals• Deer, bear and small animalsDeer, bear and small animals
o Most of this biome land area Most of this biome land area has been regenerated after has been regenerated after farming & timber harvestfarming & timber harvest
GrasslandGrasslando Grasslands with hot Grasslands with hot
summers, cold winters and summers, cold winters and too little precipitation to too little precipitation to support treessupport trees
o PrecipitationPrecipitation• 25-75 cm/yr25-75 cm/yr
o Tall grass prairiesTall grass prairieso Short grass prairiesShort grass prairieso 90% of this biome has 90% of this biome has
been lost to farmlandbeen lost to farmland
GrasslandGrasslando Soil has thick, organic materialSoil has thick, organic material
rich organic horizon.rich organic horizon.o Periodic fires keep the dominant Periodic fires keep the dominant
vegetationvegetation grassesgrasseso AnimalsAnimals
• Once covered with Once covered with bison- no longer truebison- no longer true
• Smaller animals are Smaller animals are still present (ex: still present (ex: prairie dogs)prairie dogs)
ChaparralChaparralo Also called a Also called a
Mediterranean Mediterranean ClimateClimate• Ex: Southern Ex: Southern
CaliforniaCalifornia• Ex: GreeceEx: Greece
o TemperatureTemperature• Mild, moist wintersMild, moist winters• Hot, dry summersHot, dry summers
o Frequent firesFrequent fires
ChaparralChaparralo Soil is thin and often Soil is thin and often
not fertilenot fertileo VegetationVegetation
• Dense growth of Dense growth of evergreen shrubsevergreen shrubs
• Lush during the Lush during the growing seasongrowing season
o AnimalsAnimals• Mule deer, Mule deer,
chipmunks, many chipmunks, many species of birdsspecies of birds
SavannaSavannao Tropical grassland Tropical grassland
with widely scattered with widely scattered treestrees
o TemperatureTemperature• Varies little throughout Varies little throughout
the yearthe year
o PrecipitationPrecipitation• Seasons regulated by Seasons regulated by
precipitation, not precipitation, not temperaturetemperature
• 76-150 cm/yr76-150 cm/yr
SavannaSavannao Soil low in nutrients due to leachingSoil low in nutrients due to leachingo VegetationVegetation
• Wide expanses of grassWide expanses of grass• Occasional Acacia treesOccasional Acacia trees
• Have fire adaptive Have fire adaptive characteristicscharacteristics
o AnimalsAnimals• Herds of hoofed Herds of hoofed
animalsanimals• Large predators- Large predators-
lions, hyenas, etc.lions, hyenas, etc.
Temperate Temperate RainforestRainforest
o Coniferous biome with cool weather, Coniferous biome with cool weather, dense fog and high precipitationdense fog and high precipitation• Ex: Northwest USEx: Northwest US
o PrecipitationPrecipitation• > 127 cm/yr> 127 cm/yr• Heaviest in winterHeaviest in winter
o TemperatureTemperature• Winters are mildWinters are mild• Summers are coolSummers are cool
Temperate Temperate RainforestRainforest
o Soils are nutrient-poor, but high in organic Soils are nutrient-poor, but high in organic material (dropped needles)material (dropped needles)• Cool temperatures slow decompositionCool temperatures slow decomposition
o Dominant VegetationDominant Vegetation• Large evergreen treesLarge evergreen trees• Old-growth forestOld-growth forest
o Variety of cool Variety of cool climate animal lifeclimate animal lifeo Very high speciesVery high species richnessrichnesso Heavily loggedHeavily logged
Boreal ForestsBoreal Forests
o A region of coniferous forests in the A region of coniferous forests in the northern hemispherenorthern hemisphere• Just south of tundraJust south of tundra
o Covers 11% of earth’s Covers 11% of earth’s landlando Growing SeasonGrowing Season
• A little longer than A little longer than tundratundra
o PrecipitationPrecipitation• ~ 50 cm/yr~ 50 cm/yr
Boreal ForestsBoreal Forestso Soils are acidic and mineral poorSoils are acidic and mineral pooro Vegetation comprised of drought Vegetation comprised of drought
resistant conifersresistant conifers• White spruceWhite spruce• Balsam firBalsam fir• Eastern larchEastern larch
o Mostly small Mostly small animals and animals and migrating birdsmigrating birds
o Some large animals Some large animals are presentare present• Wolves, bear, mooseWolves, bear, moose
TundraTundrao Treeless biome in the far north with Treeless biome in the far north with
harsh, cold winters and extremely harsh, cold winters and extremely short summersshort summers
o PrecipitationPrecipitation• 10-25 cm/yr10-25 cm/yr
o TemperatureTemperature• Short growing seasonShort growing season• 50-160 days50-160 days
TundraTundrao Nutrient poor soils with little organic Nutrient poor soils with little organic
materialmaterial• Permafrost presentPermafrost presento Low species richnessLow species richness• Veg is mostly grasses Veg is mostly grasses
and sedgesand sedges• Very simple food webVery simple food web
o Low primary Low primary productivityproductivity
Aquatic EcosystemAquatic Ecosystemo Fundamental DivisionFundamental Division
• FreshwaterFreshwater• SaltwaterSaltwater
o Aquatic Ecosystems also affected byAquatic Ecosystems also affected by• Dissolved oxygen level, light penetration, Dissolved oxygen level, light penetration,
pH, presence/absence of currentspH, presence/absence of currentso Three main ecological categories of Three main ecological categories of
organismsorganisms• Plankton- free floatingPlankton- free floating• Nekton- strong swimmingNekton- strong swimming• Benthos- bottom dwellingBenthos- bottom dwelling
Freshwater Freshwater EcosystemsEcosystems
o Includes:Includes:• Rivers and streamsRivers and streams• Lakes and pondsLakes and ponds• Marshes and swampsMarshes and swamps
o Represent 2% of earth’s surfaceRepresent 2% of earth’s surfaceo Assist in recycling water back to the Assist in recycling water back to the
oceans (Biogeochemical Cycling)oceans (Biogeochemical Cycling)
Rivers and StreamsRivers and Streamso Changes greatly Changes greatly
from headwater to from headwater to mouthmouth
o HeadwatersHeadwaters• Shallow, cool, Shallow, cool,
swiftly flowing, high swiftly flowing, high oxygenatedoxygenated
o MouthMouth• Not as cool, slower Not as cool, slower
flowing, less oxygen flowing, less oxygen in waterin water
Lakes and PondsLakes and Ponds
o Body of freshwater that does not flowBody of freshwater that does not flowo Three zonesThree zones
• LittoralLittoral• LimneticLimnetic• ProfundalProfundal
o Experience thermal stratification Experience thermal stratification (depending on depth)(depending on depth)
Lakes and PondsLakes and Pondso Littoral ZoneLittoral Zone - shallow water area - shallow water area
along the shorealong the shoreo Limnetic ZoneLimnetic Zone - open water beyond - open water beyond
the littoral zonethe littoral zoneo Profundal ZoneProfundal Zone - beneath the limnetic - beneath the limnetic
zone of deep lakeszone of deep lakes
Thermal StratificationThermal Stratification
o Temperature Temperature changes sharply changes sharply with depthwith depth
o ThermoclineThermocline• Temperature Temperature
transition between transition between warmer surface warmer surface water and colder water and colder water at depthwater at depth
• Only present in Only present in warm monthswarm months
Marshes and SwampsMarshes and Swampso Lands that shallow, fresh water covers Lands that shallow, fresh water covers
for at least part of the yearfor at least part of the year• Characteristic soil- water logged and Characteristic soil- water logged and
anaerobic for periods of timeanaerobic for periods of time• Water tolerant vegetationWater tolerant vegetation
o Were once regularly Were once regularly filled infilled in• More recently their More recently their
ecosystem services have ecosystem services have been better recognizedbeen better recognized
• Flood protection, waterFlood protection, water
filtering, filtering, etc.etc.
EstuariesEstuarieso Where freshwater and saltwater mixWhere freshwater and saltwater mixo Highly variable environmentHighly variable environment
• Temperature, salinity, depth of light Temperature, salinity, depth of light penetrationpenetrationo Highly productiveHighly productive
• Nutrients transported from Nutrients transported from landland
• Tidal action promotes rapid Tidal action promotes rapid circulation of nutrientscirculation of nutrients
• High level of light High level of light penetrates shallow waterpenetrates shallow water
EstuariesEstuaries
Marine EcosystemsMarine Ecosystemso Subdivided Subdivided
into life zonesinto life zones• Intertidal zoneIntertidal zone• Benthic zoneBenthic zone• Pelagic Pelagic
environmentenvironment• Neritic Neritic
ProvinceProvince• Oceanic Oceanic
ProvinceProvince
Intertidal ZoneIntertidal Zoneo Area of shoreline between low and high Area of shoreline between low and high
tidestideso HabitatHabitat• Sandy or rockySandy or rocky
o MusclesMuscleso CrabsCrabso AlgaeAlgaeo OystersOysterso BarnaclesBarnacleso Animals must Animals must
adapts to adapts to changing changing conditionsconditions
Benthic ZoneBenthic Zone
o Ocean floor, extending from tidal zone Ocean floor, extending from tidal zone to deep sea trenchesto deep sea trenches
o Sediment is mostly mudSediment is mostly mud• Burrowing worms and clamsBurrowing worms and clams
o Three zoneThree zone• Bathyal: 200m - 4000m deepBathyal: 200m - 4000m deep• Abyssal: 4000m -6000m deepAbyssal: 4000m -6000m deep• Hadal: 6000m – bottom of deep sea Hadal: 6000m – bottom of deep sea
trenchestrenches
Productive Benthic Productive Benthic CommunitiesCommunities
o Seagrass BedsSeagrass Beds• Present to depth of 10 mPresent to depth of 10 m• Provide food and habitat toProvide food and habitat to
ecosystemecosystem
o Kelp ForestKelp Forest• 60-m long brown algae found off rocky shores60-m long brown algae found off rocky shores• Diversity of life supported by kelp rivals coral reefsDiversity of life supported by kelp rivals coral reefs
o Coral ReefsCoral Reefs• Built from accumulated layers of CaCOBuilt from accumulated layers of CaCO33
• Colonies of millions of tiny coral animalsColonies of millions of tiny coral animals• Found in shallow warm waterFound in shallow warm water• Most diverse of all marine environmentsMost diverse of all marine environments
Productive Benthic Productive Benthic CommunitiesCommunities
Left: Seagrass BedLeft: Seagrass Bed
Right: Kelp ForestRight: Kelp Forest
Human DisturbanceHuman Disturbance
Human Impact on Coral ReefsHuman Impact on Coral Reefs
o SedimentationSedimentation• From clear-From clear-
cutting cutting upstreamupstream
o OverfishingOverfishingo Coral bleachingCoral bleachingo Mining of corals Mining of corals
as building as building materialsmaterials
o Runoff pollutionRunoff pollution
Pelagic EnvironmentPelagic Environment
o All the open ocean waterAll the open ocean watero Two main divisionsTwo main divisions
• Neritic ProvinceNeritic Province• Water that overlies the continental shelf (to Water that overlies the continental shelf (to
depth of 200 m)depth of 200 m)• Organisms are all floaters or swimmersOrganisms are all floaters or swimmers
• Oceanic ProvinceOceanic Province• Water that overlies depths greater than 200 mWater that overlies depths greater than 200 m• 75% of world’s ocean75% of world’s ocean• Most organisms are dependent on marine snowMost organisms are dependent on marine snow• Organisms are filter feeders, scavengers and Organisms are filter feeders, scavengers and
predatorspredators
Human Impacts on the OceanHuman Impacts on the Ocean