Chapter 6 Major Ecosystems of the World. Overview of Chapter 6 Earth’s Major Biomes Aquatic Ecosystems Freshwater ecosystems Estuaries Marine

Chapter 6Chapter 6Major Ecosystems of the WorldMajor Ecosystems of the World

Overview of Chapter 6Overview of Chapter 6

Earth’s Major BiomesEarth’s Major Biomes Aquatic EcosystemsAquatic Ecosystems

Freshwater ecosystemsFreshwater ecosystems EstuariesEstuaries

Marine EcosystemsMarine Ecosystems Interaction of Life Zones and HumansInteraction of Life Zones and Humans

Earth’s Major BiomesEarth’s Major Biomes

BiomeBiome A large, relatively distinct terrestrial A large, relatively distinct terrestrial

region with a similar climate soil, plants, region with a similar climate soil, plants, and animals, regardless of where it and animals, regardless of where it occurs in the worldoccurs in the world

Nine major biomes Nine major biomes Location of each biome is primarily Location of each biome is primarily

determined by:determined by: Temperature (varies with both latitude Temperature (varies with both latitude

and elevation)and elevation) PrecipitationPrecipitation

TundraTundra

Treeless biome in the Treeless biome in the far north with harsh, far north with harsh, cold winters and cold winters and extremely short extremely short summerssummers

PrecipitationPrecipitation 10–25 cm/yr10–25 cm/yr

TemperatureTemperature Short growing seasonShort growing season 50–160 days50–160 days

Low species Low species richnessrichness Veg is mostly Veg is mostly

grasses and sedgesgrasses and sedges Very simple food Very simple food

webweb Low primary Low primary

productivityproductivity

TundraTundra

Nutrient poor soils with little organic Nutrient poor soils with little organic materialmaterial Permafrost presentPermafrost present

Boreal ForestsBoreal Forests

A region of coniferous forests in the A region of coniferous forests in the northern hemispherenorthern hemisphere Just south of tundraJust south of tundra

Covers 11% of Earth’s Covers 11% of Earth’s

landland Growing SeasonGrowing Season

A little longer thanA little longer than

tundratundra PrecipitationPrecipitation

~ 50 cm/yr~ 50 cm/yr

White spruceWhite spruce Balsam firBalsam fir Eastern larchEastern larch

Mostly small Mostly small animals and animals and migrating birdsmigrating birds

Some large Some large animals are animals are presentpresent Wolves, bear, Wolves, bear,

moosemoose

Boreal ForestsBoreal Forests Soils are acidic and mineral poorSoils are acidic and mineral poor Vegetation comprised of drought Vegetation comprised of drought

resistant conifersresistant conifers

Temperate RainforestTemperate Rainforest

Coniferous biome with cool weather, Coniferous biome with cool weather, dense fog and high precipitationdense fog and high precipitation Ex: Northwest USEx: Northwest US

PrecipitationPrecipitation > 127 cm/yr> 127 cm/yr Heaviest in winterHeaviest in winter

TemperatureTemperature Winters are mildWinters are mild Summers are coolSummers are cool

Temperate RainforestTemperate Rainforest 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

Dominant VegetationDominant Vegetation Large evergreen treesLarge evergreen trees Old-growth forestOld-growth forest

Variety of cool Variety of cool

climate animal lifeclimate animal life Very high speciesVery high species

richnessrichness Heavily loggedHeavily logged

Temperature Deciduous Temperature Deciduous ForestsForests Forest biome that Forest biome that

occurs in temperate occurs in temperate areas with a areas with a moderate amount moderate amount of precipitationof precipitation


TemperatureTemperature SeasonalitySeasonality Hot summers and Hot summers and

cold winterscold winters

Temperate Deciduous Temperate Deciduous ForestForest Topsoil is rich in organic Topsoil is rich in organic

material and underlain by material and underlain by clayclay

Vegetation is primarily Vegetation is primarily deciduousdeciduous Oak, maple, beechOak, maple, beech

AnimalsAnimals Deer, bear and small Deer, bear and small

animalsanimals Most of this biome land Most of this biome land

area has been area has been regenerated after farming regenerated after farming & timber harvest& timber harvest

GrasslandGrassland Grasslands with hot summers, cold Grasslands with hot summers, cold

winters and too little precipitation to winters and too little precipitation to support treessupport trees


Tall grass prairiesTall grass prairies Short grass prairiesShort grass prairies 90% of this biome90% of this biome

has been lost tohas been lost to

farmlandfarmland

GrasslandGrassland Soil has thick, Soil has thick,

organic material rich organic material rich organic horizonorganic horizon

Periodic fires keep Periodic fires keep the dominant the dominant vegetationvegetation

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)

ChaparralChaparral

Also called a Mediterranean ClimateAlso called a Mediterranean Climate Ex: Southern CaliforniaEx: Southern California Ex: GreeceEx: Greece

TemperatureTemperature Mild, moist wintersMild, moist winters Hot, dry summersHot, dry summers

Frequent firesFrequent fires

ChaparralChaparral

Soil is thin and Soil is thin and often not fertileoften not fertile

VegetationVegetation Dense growth of Dense growth of

evergreen shrubsevergreen shrubs Lush during the Lush during the

growing seasongrowing season AnimalsAnimals

Mule deer, Mule deer, chipmunks, many chipmunks, many species of birdsspecies of birds

DesertsDeserts

Biome where lack Biome where lack of precipitation of precipitation limits plant growthlimits plant growth

TemperatureTemperature Can very greatly in Can very greatly in

24-hr period, as 24-hr period, as well as yearly well as yearly (based on location)(based on location)

PrecipitationPrecipitation < 25 cm/yr< 25 cm/yr

DesertsDeserts Soils low in nutrients and high in Soils low in nutrients and high in

saltssalts Vegetation sparseVegetation sparse

cactus and sagebrushcactus and sagebrush Animals are very small to regulate Animals are very small to regulate

temperaturetemperature

SavannaSavanna

Tropical grassland Tropical grassland with widely with widely scattered treesscattered trees

TemperatureTemperature Varies little Varies little

throughout the yearthroughout the year PrecipitationPrecipitation

Seasons regulated Seasons regulated by precipitation, not by precipitation, not temperaturetemperature

76–150 cm/yr76–150 cm/yr

SavannaSavanna Soil low in nutrients due to leachingSoil low in nutrients due to leaching VegetationVegetation

Wide expanses of grass, occasional Acacia Wide expanses of grass, occasional Acacia treestrees

Have fire adaptiveHave fire adaptivecharacteristicscharacteristics

AnimalsAnimals Herds of hoofedHerds of hoofed

animalsanimals Large predators -Large predators -

lions, hyenas, etc.lions, hyenas, etc.

Tropical RainforestTropical Rainforest

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


Very productive Very productive biomebiome

Most species-rich Most species-rich biomebiome

Tropical RainforestTropical Rainforest

Ancient, weathered, Ancient, weathered, nutrient-poor soilnutrient-poor soil Nutrients tied up in Nutrients tied up in

vegetation, not soilvegetation, not soil VegetationVegetation

3 distinct canopy3 distinct canopylayerslayers

AnimalsAnimals Most abundant Most abundant

insect, reptiles and insect, reptiles and amphibians on earthamphibians on earth

Vertical ZonationVertical Zonation

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

Aquatic EcosystemAquatic Ecosystem Fundamental DivisionFundamental Division

FreshwaterFreshwater SaltwaterSaltwater

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 currents 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 EcosystemsFreshwater Ecosystems

Includes:Includes: Rivers and streamsRivers and streams Lakes and pondsLakes and ponds Marshes and swampsMarshes and swamps

Represent 2% of earth’s surfaceRepresent 2% of earth’s surface Assist in recycling water back to the Assist in recycling water back to the

oceansoceans

Rivers and StreamsRivers and Streams

Lakes and PondsLakes and Ponds

Body of freshwater that does not flowBody of freshwater that does not flow Three zonesThree zones

LittoralLittoral LimneticLimnetic ProfundalProfundal

Experience thermal stratification Experience thermal stratification (depending on depth)(depending on depth)

Lakes and PondsLakes and Ponds

Littoral Zone - shallow water area along the Littoral Zone - shallow water area along the shoreshore

Limnetic Zone - open water beyond the Limnetic Zone - open water beyond the littoral zonelittoral zone

Profundal Zone - beneath the limnetic zone Profundal Zone - beneath the limnetic zone of deep lakesof deep lakes

Thermal StratificationThermal Stratification

Temperature Temperature changes sharply changes sharply with depthwith depth

ThermoclineThermocline Temperature Temperature

transition transition between warmer between warmer surface water surface water and colder water and colder water at depthat depth

Only present in Only present in warm monthswarm months

Fall TurnoverFall Turnover

Marshes and SwampsMarshes and Swamps

Lands that shallow, Lands that shallow, fresh water covers fresh water covers for at least part of for at least part of the yearthe year

Were once regularly Were once regularly filled infilled in More recently their More recently their

ecosystem services ecosystem services have been better have been better recognizedrecognized Flood protection, Flood protection,

water filtering, etc.water filtering, etc.

EstuariesEstuaries Where freshwater and saltwater mixWhere freshwater and saltwater mix Highly variable environmentHighly variable environment

Temperature, salinity, depth of light Temperature, salinity, depth of light penetrationpenetration

Highly productiveHighly productive Nutrients transportedNutrients transported

from landfrom land High level of lightHigh level of light

penetrates shallow waterpenetrates shallow water Plants providePlants provide

photosynthetic carpetphotosynthetic carpet

Marine EcosystemsMarine Ecosystems

Subdivided into life zonesSubdivided into life zones Intertidal zoneIntertidal zone Benthic zoneBenthic zone Pelagic environmentPelagic environment

Neritic ProvinceNeritic Province Oceanic ProvinceOceanic Province

Marine EcosystemsMarine Ecosystems

Intertidal ZoneIntertidal Zone

Area of shoreline between low and high Area of shoreline between low and high tidestides

Benthic ZoneBenthic Zone

Ocean floor, extending from tidal zone Ocean floor, extending from tidal zone to deep sea trenchesto deep sea trenches

Sediment is mostly mudSediment is mostly mud Burrowing worms and clamsBurrowing worms and clams

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 Seagrass BedsSeagrass Beds

Present to depth of 10 mPresent to depth of 10 m Provide food and habitat to ecosystemProvide food and habitat to ecosystem

Kelp ForestKelp Forest 60 m long brown algae found off rocky shores60 m long brown algae found off rocky shores Large BiodiversityLarge Biodiversity

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

Left:Left:

SeagrassSeagrass

BedBed

Right:Right:

Kelp Kelp ForestForest

Productive Benthic Productive Benthic CommunitiesCommunities

Coral Reef EnvironmentsCoral Reef Environments

Three types of Three types of coral reefscoral reefs Fringing reef - Fringing reef -

directly attach to directly attach to continent - no continent - no lagoonlagoon

Atoll - circular Atoll - circular reef in a lagoonreef in a lagoon

Barrier reef - Barrier reef - separates lagoon separates lagoon from oceanfrom ocean

Human Impact on Coral Human Impact on Coral ReefsReefs SedimentationSedimentation

From clear-cutting upstreamFrom clear-cutting upstream OverfishingOverfishing Coral bleachingCoral bleaching Mining of corals as building materialsMining of corals as building materials Runoff pollutionRunoff pollution

Pelagic EnvironmentPelagic Environment

All the open ocean waterAll the open ocean water 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 Organisms are filter feeders, scavengers and Organisms are filter feeders, scavengers and

predatorspredators

Human Impacts on the Human Impacts on the OceanOcean

Documents

Chapter 6 Major Ecosystems of the World. Overview of Chapter 6 Earth’s Major Biomes Aquatic Ecosystems Freshwater ecosystems Estuaries Marine