The BiosphereThe Biosphere

Chapter 42Chapter 42

ClimateClimate

Average weather condition in a region

Affected by:

amount of incoming solar radiation

prevailing winds

elevation

Average weather condition in a region

Affected by:

amount of incoming solar radiation

prevailing winds

elevation

The AtmosphereThe Atmosphere

Three layers

Outer mesosphere

Middle stratosphere (includes ozone layer)

Inner troposphere (where air is warmed by

the greenhouse effect)

Three layers

Outer mesosphere

Middle stratosphere (includes ozone layer)

Inner troposphere (where air is warmed by

the greenhouse effect)

Warming the AtmosphereWarming the Atmosphere

Solar energy warms the atmosphere and sets

global air circulation patterns in motion

Solar energy warms the atmosphere and sets

global air circulation patterns in motion

Rotation and Wind DirectionRotation and Wind Direction

Earth rotates faster under the air at the equator than it does at the poles

Deflection east and west

Earth rotates faster under the air at the equator than it does at the poles

Deflection east and west

Seasonal VariationSeasonal Variation

Northern end of Earth’s axis tilts toward

sun in June and away in December

Difference in tilt causes differences in

sunlight intensity and day length

The greater the distance from the equator,

the more pronounced the seasonal changes

Northern end of Earth’s axis tilts toward

sun in June and away in December

Difference in tilt causes differences in

sunlight intensity and day length

The greater the distance from the equator,

the more pronounced the seasonal changes

Varying TemperaturesVarying Temperaturescold

cool temperature

warm temperature

tropical(equator)tropical

warm temperature

cool temperature

cold March

December

September

June

231/2º

PollutantsPollutants

Substances with which an ecosystem

has had no prior evolutionary

experience

No adaptive mechanisms are in place

to deal with them

Substances with which an ecosystem

has had no prior evolutionary

experience

No adaptive mechanisms are in place

to deal with them

Ozone ThinningOzone Thinning

In early spring and summer ozone

layer over Antarctica thins

Seasonal loss of ozone is at highest

level ever recorded

In early spring and summer ozone

layer over Antarctica thins

Seasonal loss of ozone is at highest

level ever recorded

Effect of Ozone ThinningEffect of Ozone Thinning

Increased amount of UV radiation

reaches Earth’s surface

UV damages DNA and negatively

affects human health

UV also affects plants, lowers primary

productivity

Increased amount of UV radiation

reaches Earth’s surface

UV damages DNA and negatively

affects human health

UV also affects plants, lowers primary

productivity

Air PollutantsAir Pollutants

Carbon oxides

Sulfur oxides

Nitrogen oxides

Volatile organic compounds

Photochemical oxidants

Suspended particles

Carbon oxides

Sulfur oxides

Nitrogen oxides

Volatile organic compounds

Photochemical oxidants

Suspended particles

Protecting the Ozone LayerProtecting the Ozone Layer

CFC production has been halted in

developed countries, will be phased out in

developing countries

Methyl bromide will be phased out

Even with bans it will take more than 50

years for ozone levels to recover

CFC production has been halted in

developed countries, will be phased out in

developing countries

Methyl bromide will be phased out

Even with bans it will take more than 50

years for ozone levels to recover

Thermal InversionThermal Inversion

Weather pattern in which a layer of cool, dense air is trapped beneath a layer of warm air

Weather pattern in which a layer of cool, dense air is trapped beneath a layer of warm air

cool air

warm inversion air

cool air

normal circulationcool air

warm air

cooler air

Industrial SmogIndustrial Smog

Gray-air smog

Forms over cities that burn large amounts of

coal and heavy fuel oils; mainly in

developing countries

Main components are sulfur oxides and

suspended particles

Gray-air smog

Forms over cities that burn large amounts of

coal and heavy fuel oils; mainly in

developing countries

Main components are sulfur oxides and

suspended particles

Photochemical SmogPhotochemical Smog

Brown-air smog

Forms when sunlight interacts with

components from automobile exhaust

Nitrogen oxides are the main culprits

Hot days contribute to formation

Brown-air smog

Forms when sunlight interacts with

components from automobile exhaust

Nitrogen oxides are the main culprits

Hot days contribute to formation

Acid DepositionAcid Deposition

Caused by the release of

sulfur and nitrogen

oxides

Coal-burning power

plants and motor vehicles

are major sources

Caused by the release of

sulfur and nitrogen

oxides

Coal-burning power

plants and motor vehicles

are major sources

Suspended Particulate MatterSuspended Particulate Matter

Ocean CurrentsOcean Currents Upper waters move in currents that distribute nutrients

and affect regional climates

Upper waters move in currents that distribute nutrients

and affect regional climates

Rain ShadowRain Shadow

Air rises on the windward side, loses moisture

before passing over the mountain

Air rises on the windward side, loses moisture

before passing over the mountain

MonsoonsMonsoons

A pattern of wind circulation that changes

seasonally

Affect continents north and south of warm-

water oceans

Can cause seasonal variation in rains

A pattern of wind circulation that changes

seasonally

Affect continents north and south of warm-

water oceans

Can cause seasonal variation in rains

Coastal BreezesCoastal Breezes

Breeze blows in direction of warmer region Direction varies with time of day

Breeze blows in direction of warmer region Direction varies with time of day

Biogeographic RealmsBiogeographic Realms

Six areas in which plants and animals

are somewhat similar

Maintain their identity because of

climate and physical barriers that tend

to maintain isolation between species

Six areas in which plants and animals

are somewhat similar

Maintain their identity because of

climate and physical barriers that tend

to maintain isolation between species

BiomesBiomes

Regions of land characterized by habitat

conditions and community structure

Distinctive biomes prevail at certain

latitudes and elevations

Regions of land characterized by habitat

conditions and community structure

Distinctive biomes prevail at certain

latitudes and elevations

nearctic

neotropical

australian

oriental

palearctic

ethiopian

Hot SpotsHot Spots

Portions of biomes that show the greatest

biodiversity

Conservationists are working to inventory

and protect these regions

24 hot spots hold more than half of all

terrestrial species

Portions of biomes that show the greatest

biodiversity

Conservationists are working to inventory

and protect these regions

24 hot spots hold more than half of all

terrestrial species

DesertsDeserts

Less than 10 centimeters annual

rainfall, high level of evaporation

Tend to occur at 30 degrees north and

south and in rain shadows

One third of land surface is arid or

semiarid

Less than 10 centimeters annual

rainfall, high level of evaporation

Tend to occur at 30 degrees north and

south and in rain shadows

One third of land surface is arid or

semiarid

Dry Shrublands and WoodlandsDry Shrublands and Woodlands

Semiarid regions with cooler, wet

winters and hot, dry summers

Tend to occur in western or southern

coastal regions between latitudes of

30 and 40 degrees

Semiarid regions with cooler, wet

winters and hot, dry summers

Tend to occur in western or southern

coastal regions between latitudes of

30 and 40 degrees

Forest BiomesForest Biomes

Tall trees form a continuous canopy

Evergreen broadleaves in tropical latitudes

Deciduous broadleaves in most temperate

latitudes

Evergreen conifers at high temperate elevations

and at high latitudes

Tall trees form a continuous canopy

Evergreen broadleaves in tropical latitudes

Deciduous broadleaves in most temperate

latitudes

Evergreen conifers at high temperate elevations

and at high latitudes

Arctic TundraArctic Tundra

Occurs at high latitudes between

polar ice cap and boreal forests

Summers are short and snow-free

Permafrost lies beneath surface,

causes waterlogging in summer

Nutrient cycling is very slow

Occurs at high latitudes between

polar ice cap and boreal forests

Summers are short and snow-free

Permafrost lies beneath surface,

causes waterlogging in summer

Nutrient cycling is very slow

Alpine TundraAlpine Tundra

Occurs at high elevations throughout the world

No underlying permafrost

Plants are low, cushions or mats as in arctic

tundra

Occurs at high elevations throughout the world

No underlying permafrost

Plants are low, cushions or mats as in arctic

tundra

How much are you aware?How much are you aware?Is the native vegetation of the place where you live forest,

grassland, or dessert?

Can you describe the physical characteristics of three plant species that are native to your area?

What body of water serves as the source of your tap water?

How is your electricity generated?

Where does your garbage go?

Is the native vegetation of the place where you live forest, grassland, or dessert?

Can you describe the physical characteristics of three plant species that are native to your area?

What body of water serves as the source of your tap water?

How is your electricity generated?

Where does your garbage go?

Biomes - LandBiomes - Land

Primary vegetation types Four basic land biomes:

Forest Grassland Desert Tundra

Primary vegetation types Four basic land biomes:

Forest Grassland Desert Tundra

Biomes - LandBiomes - Land

Forest Tropical forests - Highly diverse and capture all light Temperate forests - Deciduous trees which drop leaves annually Boreal forests - highly uniform, coniferous trees of 1 or 2 species Chaparrel - woody spiny evergreen shrubs

Grassland - area where rainfall is not enough for tree growth Tropical - savannas - free trees - cleared by fires Temperate - prairies (tall grass) and steppes (short grass)

Forest Tropical forests - Highly diverse and capture all light Temperate forests - Deciduous trees which drop leaves annually Boreal forests - highly uniform, coniferous trees of 1 or 2 species Chaparrel - woody spiny evergreen shrubs

Grassland - area where rainfall is not enough for tree growth Tropical - savannas - free trees - cleared by fires Temperate - prairies (tall grass) and steppes (short grass)

Biomes - LandBiomes - Land

Desert Rainfall is sparse Animals and plants have evolved ways to conserve

water

Tundra Coldest biome - close to the poles Permafrost - keeps soils moist and bogged

Desert Rainfall is sparse Animals and plants have evolved ways to conserve

water

Tundra Coldest biome - close to the poles Permafrost - keeps soils moist and bogged

Biomes - AquaticBiomes - Aquatic

Freshwater Lakes and Ponds - surrounded by land

Vernal ponds - dry up in the summer

Rivers and Streams - flowing water Wetlands - support above water plants

Saltwater Oceans Coral reefs Estuaries

Freshwater Lakes and Ponds - surrounded by land

Vernal ponds - dry up in the summer

Rivers and Streams - flowing water Wetlands - support above water plants

Saltwater Oceans Coral reefs Estuaries

Soil Characteristics Soil Characteristics

Amount of humus

pH

Degree of aeration

Ability to hold or drain water

Mineral content

Amount of humus

pH

Degree of aeration

Ability to hold or drain water

Mineral content

Soil ProfilesSoil Profiles

Layer structure of

soil

Soil characteristics

determine what

plants will grow and

how well

Layer structure of

soil

Soil characteristics

determine what

plants will grow and

how well

Rain forest

Desert

Grassland

Deciduous Coniferous

LakesLakes

Bodies of standing freshwater

Eutrophic lake is shallow, nutrient-rich, has

high primary productivity

Oligotrophic lake is deep, nutrient-poor,

has low primary productivity

Bodies of standing freshwater

Eutrophic lake is shallow, nutrient-rich, has

high primary productivity

Oligotrophic lake is deep, nutrient-poor,

has low primary productivity

Lake ZonationLake Zonation

LITTORAL

limit of effective light penetration

LIMNETICLITTORAL

PROFUNDAL

Thermal LayeringThermal Layering

In temperate-zone lakes, water can form distinct layers during summer

In temperate-zone lakes, water can form distinct layers during summer

wind

THERMOCLINE

Seasonal OverturnSeasonal Overturn

In spring and autumn, temperatures in the

lake become more uniform

Oxygen-rich surface waters mix with

deeper oxygen-poor layers

Nutrients that accumulated at bottom are

brought to the surface

In spring and autumn, temperatures in the

lake become more uniform

Oxygen-rich surface waters mix with

deeper oxygen-poor layers

Nutrients that accumulated at bottom are

brought to the surface

EutrophicationEutrophication

How do nutrients enter a lake?

Can occur naturally over long time span

Can be triggered by pollutants

How do nutrients enter a lake?

Can occur naturally over long time span

Can be triggered by pollutants

StreamsStreams

Begin as springs or seeps

Carry nutrients downstream

Solute concentrations are influenced by

streambed composition and human

activities

Begin as springs or seeps

Carry nutrients downstream

Solute concentrations are influenced by

streambed composition and human

activities

EstuaryEstuary

Partially enclosed area where

saltwater and freshwater mix

Dominated by salt-tolerant plants

Examples are Chesapeake Bay, San

Francisco Bay, salt marshes of New

England

Partially enclosed area where

saltwater and freshwater mix

Dominated by salt-tolerant plants

Examples are Chesapeake Bay, San

Francisco Bay, salt marshes of New

England

Estuarine Food WebsEstuarine Food Webs

Primary producers are phytoplankton and

salt-tolerant plants

Much primary production enters detrital

food webs

Detritus feeds bacteria, nematodes, snails,

crabs, fish

Primary producers are phytoplankton and

salt-tolerant plants

Much primary production enters detrital

food webs

Detritus feeds bacteria, nematodes, snails,

crabs, fish

Mangrove WetlandsMangrove Wetlands

Tropical saltwater ecosystem

Form in nutrient-rich tidal flats

Dominant plants are salt-tolerant

mangroves

Florida, Southeast Asia

Tropical saltwater ecosystem

Form in nutrient-rich tidal flats

Dominant plants are salt-tolerant

mangroves

Florida, Southeast Asia

Rocky IntertidalRocky Intertidal

Grazing food webs prevail

Vertical zonation is readily apparent

Diversity is greatest in the lower littoral

zone

Grazing food webs prevail

Vertical zonation is readily apparent

Diversity is greatest in the lower littoral

zone

Sandy CoastlinesSandy Coastlines

Vertical zonation is less obvious than along

rocky shores

Detrital food webs predominate

Vertical zonation is less obvious than along

rocky shores

Detrital food webs predominate

Intertidal ZonesIntertidal Zones

Littoral zone is submerged only during

highest tides of the year

Midlittoral zone is regularly submerged and

exposed

Lower littoral is exposed only during

lowest tides of the year

Littoral zone is submerged only during

highest tides of the year

Midlittoral zone is regularly submerged and

exposed

Lower littoral is exposed only during

lowest tides of the year

Coral ReefsCoral Reefs

Develop in clear, warm waters near coasts or around volcanic islands, mainly between latitudes 25° north and south

Coral bleaching is on the rise – occurs when sea temperatures rise

Develop in clear, warm waters near coasts or around volcanic islands, mainly between latitudes 25° north and south

Coral bleaching is on the rise – occurs when sea temperatures rise

Ocean ProvincesOcean Provinces

Benthic province - sediments and

rocks at bottom

Pelagic province - full volume of water

Neritic zone is near continental shelves

Oceanic zone is ocean basins

Benthic province - sediments and

rocks at bottom

Pelagic province - full volume of water

Neritic zone is near continental shelves

Oceanic zone is ocean basins

The Open OceanThe Open Oceanoceanic

zone

BENTHIC PROVINCE

PELAGIC PROVINCE 0

200

1,000

2,000

4,000

11,0000 depth (meters)

air at surfacecontinental

shelf

bathyal zone

abyssal zone

hadal zone

deep-sea trenches

sunlit water

"twilight" watersunless

water

intertidal zone

neritic zone

PhytoplanktonPhytoplankton

Floating or weakly swimming

photoautotrophs; form the base for most

oceanic food webs

Ultraplankton are photosynthetic bacteria

Floating or weakly swimming

photoautotrophs; form the base for most

oceanic food webs

Ultraplankton are photosynthetic bacteria

Deep Ocean Food WebsDeep Ocean Food Webs

Regions too dark for photosynthesis Marine snow supports a detrital food web Organic matter drifts down from shallower

water Diverse species migrate up and down in

water column daily

Regions too dark for photosynthesis Marine snow supports a detrital food web Organic matter drifts down from shallower

water Diverse species migrate up and down in

water column daily

Hydrothermal VentsHydrothermal Vents

Openings in ocean floor that spew mineral-rich, superheated water

Primary producers are chemoautotrophic bacteria; use sulfides as energy source

Life may have originated in similar conditions on early Earth

Openings in ocean floor that spew mineral-rich, superheated water

Primary producers are chemoautotrophic bacteria; use sulfides as energy source

Life may have originated in similar conditions on early Earth

UpwellingUpwelling

Upward movement of water along a coast; replaces surface waters that move away from shore

Upward movement of water along a coast; replaces surface waters that move away from shore

ENSOENSO

El Nino Southern Oscillation

Climactic event that involves changes

in sea surface temperature and air

circulation patterns in the equatorial

Pacific Ocean

El Nino Southern Oscillation

Climactic event that involves changes

in sea surface temperature and air

circulation patterns in the equatorial

Pacific Ocean

Between ENSOsBetween ENSOs

Warm water and heavy rainfall move west

across the Pacific

Warm moist air rises in the western Pacific

causing storms

Upwelling of cool water along western

coasts

Warm water and heavy rainfall move west

across the Pacific

Warm moist air rises in the western Pacific

causing storms

Upwelling of cool water along western

coasts

Between an ENSOBetween an ENSOclear skies, dry descending air

masses, high pressure

equatorial trade winds blow east to west

warm, moist, ascending air masses, low pressure, storms in western Pacific

warming water

upwelling of cold water to 30-160 feet below surface

high winds blow west to east

During an ENSODuring an ENSO

Trade winds weaken and warm water flows east

across the Pacific

Sea surface temperatures rise

Upwelling along western coasts ceases

Heavy rainfall occurs along coasts, droughts

elsewhere

Trade winds weaken and warm water flows east

across the Pacific

Sea surface temperatures rise

Upwelling along western coasts ceases

Heavy rainfall occurs along coasts, droughts

elsewhere

During ENSOsDuring ENSOsclear skies, descending air masses, high pressure

high winds blow west

warm, moist ascending air masses, low

pressure, storms

rain falls in central Pacific

no upwelling; cold water as deep as 500 feet below surface

trade winds weaken; warm water flows east

Cholera ConnectionCholera Connection

Cholera outbreaks are correlated with rises

in sea temperature

Dormant stage of causative organism lives

in copepods

Copepod population increases when

phytoplankton increase in warming seas

Cholera outbreaks are correlated with rises

in sea temperature

Dormant stage of causative organism lives

in copepods

Copepod population increases when

phytoplankton increase in warming seas