Climate and Biodiversity

Dust Storm from Africa’s Sahara Desert

What Factors Influence Climate?

An area’s climate is determined mostly by: Solar radiation Earth’s rotation Global patterns of air and water movement Gases in the atmosphere Earth’s surface features.

Many Different Climates

Weather – local area of short-term physical conditions such as humidity, wind speed, cloud cover, etc.

Climate- an area’s general pattern of atmospheric conditions over longer periods of time – usually decades or thousands of years.

Temperature and precipitation determine climate Latitude and elevation determine average

temperature and precipitation

Generalized Map of Earth's Climate

Solar Radiation

Earth’s Rotation

As the Earth rotates around its axis, its equator spins faster than the polar regions.

As a result, heated air masses rising above the equator cause the formation of cells distinguished by differing direction of air movement (prevailing winds)

Energy Transfer by Convection

Global Air Circulation

Caused by three factors• Uneven heating of earth’s surface• Rotation of the earth• Variations in properties of air, water, and land

Six cyclical convection cells

Cell Formation

Earth’s Prevailing Winds

Fig. 5-3, p. 77

Cold deserts

Cold deserts

Forests

Forests

Forests

Equator

Hot deserts

Hot deserts

Westerlies

Northeast trades

Southeast trades

Westerlies

Global Air Circulation

Fig. 5-5, p. 78

Moist air rises,cools, and releasesmoisture as rain

Desert

Desert

Equator

Polar cap

Polar capArctic tundra

Evergreenconiferous forestTemperate deciduousforest and grassland

Tropical deciduous forest

Tropical deciduous forest

Temperate deciduousforest and grassland

Tropical rain forest

Global Ocean Currents (1)

Affects regional climates

Warm and cold currents created by differences in water density

Altered by earth’s rotation and continents

Redistributes heat, mixes ocean waters, and distributes nutrients and oxygen

Global Currents (2)

Loop of deep and shallow ocean currents

Moves energy around the globe

Ocean and atmosphere closely linked

Earth’s Conveyer Belt

Fig. 5-6, p. 79

Cold, salty,deep current

Warm, lesssalty, shallowcurrent

Animation: Global Ocean and Winds Currents

Examine global surface currents.

El Niño (El Niño Southern Oscillation or ENSO)

El Niño is characterized by unusually warm ocean temperatures in the Equatorial Pacific, as opposed to La Niña, which characterized by unusually cold ocean temperatures in the Equatorial Pacific. El Niño is an oscillation of the ocean-atmosphere system in the tropical Pacific having important consequences for weather around the globe.

El Niño

El Niño

Among these consequences are increased rainfall across the southern tier of the US and in Peru, which has caused destructive flooding, and drought in the West Pacific, sometimes associated with devastating brush fires in Australia. Observations of conditions in the tropical Pacific are considered essential for the prediction of short term (a few months to 1 year) climate variations.

La Niña

Opposite of the boy, colder than normal ocean temps.

La Niña causes mostly the opposite effects of El Niño, for example, El Niño would cause a wet period in the Midwestern U.S., while La Niña would typically cause a dry period in this area.

Earth’s Surface Features and Climate

Heat absorbed and released more slowly by water than by land

Large bodies of water moderate climate

Movement of moist ocean air across a mountain• Rain and snow on windward side• Rain shadow on leeward side – e.g. Death

Valley

Rain Shadow Effect

Fig. 5-7, p. 80

On the leeward side of the mountain range, air descends, warms, andreleases little moisture.

Prevailing windspick up moisturefrom an ocean.

On the windward side of a mountain range, air rises,cools, and releases moisture.

How Does Climate Affect the Nature and Location of Biomes?

Differences in average annual precipitation and temperature lead to the formation of tropical, temperate, and cold deserts, grasslands, and forests, and largely determine their locations.

Climate Affects Biomes

Major biomes related to climate

Biomes consist of a mosaic of patches of communities

Average temperature and precipitation determine the biome

Earth’s Major Biomes

Fig. 5-8, p. 81

Correlation Between Latitude and Elevation

Fig. 5-9, p. 81

ElevationMountainice and snowTundra (herbs,lichens, mosses)

TropicalForest

DeciduousForest

ConiferousForest

Polar iceand snow

Latitude

TropicalForest

DeciduousForest

ConiferousForest

Tundra (herbs, lichens,

mosses)

Climate Determines the Biome

Fig. 5-10, p. 82

Polar

Subpolar

Temperate

Tropical

Desert

Desert

Grassland

Savanna

Scrubland

Chaparral

Coniferous forest

Tundra

Deciduousforest

Tropicalseasonal

forest

Rain forest

Three Major Types of Deserts

Tropical deserts – Sahara, Namib

Temperate deserts – Mojave

Cold deserts – Gobi

Climate Graph of Tropical United Arab Emirates Desert

Climate Graph of Temperate Arizona Desert

Climate Graph of Cold Gobi Desert

Fig. 5-11, p. 83

Three Major Types of Grasslands

Tropical grasslands – savanna

Temperate grasslands – prairie• Short-grass vs. tall-grass

Cold grasslands – tundra• Permafrost soils

Savanna Grassland

Montana Prairie Grassland

Arctic Tundra Grassland

Fig. 5-12, p. 85

Loss of a Temperate Grassland

Fig. 5-13, p. 86

Three Major Types of Forests

Tropical rain forests

Temperate deciduous forests

Evergreen coniferous forests

Tropical Forest

Temperate Deciduous Forest

Evergreen Coniferous Forest (taiga, boreal forest)

Fig. 5-14, p. 87

Tropical Rain Forest Ecosystem

Fig. 5-15, p. 88

Harpyeagle

Ocelot

Squirrelmonkeys

Katydid

Green tree snake

Tree frog

BromeliadBacteria

Fungi

Ants

Slaty-tailedtrogon

Climbingmonstera palm

Blue andgold macaw

Producerto primaryconsumer

Primaryto secondaryconsumer

All producers andconsumers todecomposers

Secondary tohigher-levelconsumer

Stratification of Tropical Rain Forest

Fig. 5-16, p. 89

Harpyeagle

Tocotoucan

Woolyopossum

Braziliantapir

Black-crownedantpitta

Groundlayer

Shrublayer

Under story

Canopy

Emergentlayer

Importance of Mountains

Contain majority of the world’s forests

Regulate climate

Key in the hydrological cycle

Ecological Role of Mountains

How Have We Affected the World’s Terrestrial Ecosystems?

In many areas, human activities are impairing ecological and economic services provided by the earth’s deserts, grasslands, forests, and mountains.

Humans Affect World’s Terrestrial Ecosystems

Disturbed most of the earth’s land

62% degraded or used unsustainably

All biomes being degraded

Major Human Impacts on World Biomes

What Are the Major Types of Aquatic Systems?

Saltwater and freshwater aquatic life zones cover almost three-fourths of the earth’s surface with oceans dominating the planet.

Most aquatic organisms live in the surface, middle, or bottom layers of saltwater and freshwater systems.

Aquatic Life Zones

Two major types• Marine (saltwater)• Freshwater

Oceans contain 97% of earth’s water

The Ocean Planet

Fig. 5-19, p. 92

Ocean hemisphere Land–ocean hemisphere

Types of Aquatic Life

Plankton – phytoplankton, zooplankton

Nekton

Benthos

Decomposers

Distribution of Aquatic Organisms

Occupy surface, middle, or bottom layers

Factors determining types and numbers of organisms• Temperature• Access to sunlight• Dissolved oxygen• Nutrient availability

The Ocean’s Natural Capital

Fig. 5-20, p. 93

What Are the Major Ocean Zones and How Have We Affected Them?

In many areas, human activities are impairing ecological and economic services provided by the earth’s saltwater systems, especially coastal wetlands, mangrove forests, and coral reefs.

Marine System Services

Fig. 5-21, p. 94

Major Life Zones of Oceans

Coastal

Open sea

Ocean bottom

Ocean Life Zones

Fig. 5-22, p. 95

AbyssalZone

High tideLow tide

EstuarineZone

Continentalshelf

Coastal Zone

Open Sea

Sea level

Sun

Euphotic Zone

Bathyal Zone

Upwelling

Estuary Photo Taken from Space

Fig. 5-23, p. 95

Food Web of a Salt Marsh

Fig. 5-24, p. 96

Herring gulls

Snowyegret

Phytoplankton

Soft-shelledclam

Bacteria

Zooplankton and

small crustaceans

Smelt

Clamworm

Marshperiwinkle

Cordgrass

Peregrine falcon

Short-billeddowitcher

All consumersand producersto decomposers

Producer toprimaryconsumer

Primary tosecondaryconsumer

Secondary tohigher-levelconsumer

The Coastal Zone

Coastal wetlands and estuaries among earth’s most productive zones

Estuaries• Provide ecosystem services• Provide economic services• Face increasing stress from human activities

Tides: Rocky and Sandy Shores

Tides

Intertidal zone

Intertidal organisms adapt to stresses of changing environment

Rocky shores

Sandy shores

Rocky Shore Beach

Fig. 5-25a, p. 97

Sea urchin

Rocky Shore Beach Sea star Hermit crab Shore crab

High tide

Periwinkle

Mussel

Barnacles

Sea lettuceKelp

Monterey flatworm

Low tide

Nudibranch

Anemone

Sculpin

Sandy Barrier Beach

Fig. 5-25b, p. 97

Barrier Beach

Beach flea

Moon snailSand dollarWhite sand macoma

Moleshrimp

Ghostshrimp

Tigerbeetle

High tide

Clam

SandpiperSilversides Low tide

Blue crabDwarfolive

Peanut worm

Sand Dunes and Barrier Beaches

Fig. 5-26, p. 98

Secondary DuneOcean Beach Bay or LagoonPrimary Dune TroughRecreation,no building

Grasses or shrubsTaller shrubs

Walkways,no building

Limitedrecreation

and walkways

Bay shore

Taller shrubs and trees

Back DuneMost suitable

for developmentRecreationWalkways,

no building

Coral Reefs

Form in clear, warm coastal waters of the subtropics and tropics

Polyps – symbiotic relationship with zooxanthellae algae

Very diverse habitat

Face great threat of destruction

The Open Sea

Separated from coastal areas by continental shelf edge

Euphotic zone

Bathyal zone

Abyssal zone

Threats to Oceans from HumanActivity (1)

Coastal development

Overfishing

Point and nonpoint source pollution

Threats to Oceans from HumanActivity (2)

Habitat destruction

Invasive species

Climate change

Human Impacts on Marine Ecosystems

Fig. 5-27, p. 99

What Are the Major Types of Freshwater Systems and How Have We Affected Them?

Human activities are impairing ecological and economic services provided by many rivers and freshwater lakes and wetlands.

Freshwater Systems

Standing water

Flowing water

Natural Capital of Freshwater Systems

Fig. 5-28, p. 100

Four Lake Zones

Littoral zone

Limnetic zone

Profundal zone

Benthic zone

Zones of a Temperate Lake

Fig. 5-29, p. 101

Limnetic zone

SunlightPainted

turtle

Greenfrog

Pondsnail

Divingbeetle

Blue-wingedteal

Northernpike

Yellow perch

Muskrat

PlanktonLittoral zone

Benthic zone

Profundal zone

Bloodworms

Nutrient Content of Lakes

Lakes classified by nutrient content and primary productivity• Oligotrophic – low productivity• Eutrophic – high productivity• Mesotrophic – middle of the road

Lakes impacted by nutrients from human activity• Cultural eutrophication – introduction of

fertilizers, sewage, etc hypereutrophication

Nutrients and Lakes

Fig. 5-30, p. 101

Watersheds

Surface water becomes runoff into streams

Watersheds or drainage basins deliver runoff, sediment, and dissolved substances to streams

Streams join to form rivers

Rivers begin in mountains or at higher elevation

Three Zones in the Downhill Flow of Water

Source zone

Transition zone

Floodplain zone

Three Zones of a Watershed

Fig. 5-31, p. 102

Depositedsediment

Rain and snow

Lake

RapidsGlacier

Waterfall

Flood plainTributary

Oxbow lake

Source Zone

Transition Zone

Floodplain Zone

Salt marsh

WaterSediment

Delta

Ocean

Rain and snowLake

RapidsGlacier

Waterfall

Source Zone

Flood plainTributary

Transition Zone

Depositedsediment

Oxbow lake

Floodplain Zone

Salt marsh

WaterSediment

Delta

Ocean

Fig. 5-31, p. 102Stepped Art

Freshwater Wetlands

Inland wetlands• Marshes• Swamps• Prairie potholes• Floodplains• Arctic tundra

Ecological and economic services

Human Impacts on Freshwater Systems

Dams and canals fragment 40% of world’s largest rivers

Flood control levees alter rivers

Cities and farmlands add pollutants

Many wetlands drained or filled