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SPECTRUM OF HABITATS:

ECOLOGICAL BIODIVERSITYTHIS COLLECTION IS ONE OF MANY FROM THE DYNAMICMUSEUM™ SERIES

Species of all kinds form close associations

within the earth’s many habitats — the eco-

logical side of biodiversity. Organisms

interact with one another to gain the energy

necessary for living, growing,

and reproducing. Plants and

some microbes first convert

the sun’s energy into sugars

through photosynthesis. These organisms

are eaten by animals and by other microbes,

which in turn may be consumed by still

others. Fungi and microbes complete this

cycle by decomposing dead matter.

“Ecosystems,” which can be entire forests

or a single lake, are the arenas within which

these energy flows take place,

as species interact with one

another and the physical

environment. Each organism

plays a role within its local ecosystem, and all

ecosystems are linked to form a single global

ecological unit, the “biosphere.”

For more information please visit http://www.amnh.org

the 9 generalkinds ofhabitats

surveyed here contain most of

the earth’sbiodiversity.

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Biodiversity is distributed unevenly throughout the earth’s ecosytems.There are usually more species within tropical regions than withinareas closer to the North and South Poles, even when similar kinds ofecosystems, such as rivers or forests, are compared. A singlehectare of coniferous forest in northern Canada has an average of1 to 5 different tree species, compared with 10 to 30 species in aneastern United Statesdeciduous forest, and40 to 100 species ina Central Americantropical rainforest.

This difference is calleda “biodiversity gradient.”Such a gradient is alsofound on mountains, withfewer species living athigher elevations.

LAKES AND RIVERS

GRASSLAND

TROPICAL FOREST

DESERT

TEMPERATE FOREST

BOREAL FOREST

TUNDRA

MIXED MOUNTAIN SYSTEMS OR ICE

spectrum of habitats:

distribution of ecological biodiversity

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TUNDRA

ECOSYSTEM BENEFITS

BASIS OF TRADITIONAL ECONOMIES OF ALEUT, INUIT, LAPLANDERS, AND OTHER NORTHERN PEOPLES •

IN SUMMER, HOME TO MANY BREEDING AND MIGRATORY BIRDS

THE TUNDRA IS ONE OF NINE FEATURED HABITATS IN THE HALL OF BIODIVERSITY AT THE AMERICAN MUSEUM OF NATURAL HISTORY

COVERAGE

1.4% OF THE EARTH’S SURFACE

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Tundras are relatively dry and treeless plains

found primarily on the edges of glacial ice

fields or polar seas. Similar cold and windy

conditions, however, produce meadows of

alpine tundra on high mountains above

timberline and below permanent snows.

Tundra vegetation consists of numerous

species of lichens, mosses, and other low

plants capable of withstanding the harsh,

exposed environment. Alpine tundras are

home primarily to birds and insects, with only

occasional grazing or predatory mammals, but

the expansive arctic tundra supports musk-

oxen, polar bears, reindeer, lemmings, and

arctic foxes as well. Because tundras are located

in high latitudes and altitudes, they may be

especially vulnerable to climatic change and to

increased ultraviolet radiation resulting from

the thinning ozone layer.

TUNDRA

EXAMPLES: NORTHERN MARGIN OF NORTH AMERICA AND EURASIA • SUB-ANTARCTIC ISLANDS • ALPINE TUNDRA SUCH AS THE ANDEAN PARAMOS (PLATEAUS) OR HIGH HIMALAYAN MEADOWS ©

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Grasslands, prairies, savannas, and steppes are

dominated by grasses with a few scattered

trees, and may grade into scrublands with

more bushes and small trees, depending on

seasonality and rainfall. Found on all

continents except Antarctica, they support a

rich fauna of grazing mammals such as bison,

antelope, zebras, and kangaroos, along with

their predators. Grasslands are highly

endangered because their fertile soils make

them the preferred habitats for human

agricultural use: since 1860, more than 650

million hectares of grassland have been

converted to croplands. Grasslands are also

used as pasture, with wild grazers replaced by

domesticated livestock — often in much higher

densities, and causing more destruction to the

soils and vegetation.

GRASSLANDS AND SAVANNAS

ECOSYSTEM BENEFITS

SUSTENANCE FOR REMNANT HUNTER-GATHERERS AND MANY OF THE WORLD’S REMAINING LARGE HERDS OFMAMMALS • NUMEROUS SPECIES OF PLANTS AND ANIMALS WERE DOMESTICATED FROM GRASSLAND SPECIES• HELP MODERATE REGIONAL CLIMATES AND REGULATE THE AMOUNT OF CARBON IN THE ATMOSPHERE •MAINTAIN SOIL FERTILITY AND RETAIN MOISTURE • CONTROL EROSION

THESE HABITATS ARE FEATURED IN THE HALL OF BIODIVERSITY AT THE AMERICAN MUSEUM OF NATURAL HISTORY

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many

grasslands

are becoming

deserts through

overgrazing; soil

compaction and

pollution; and

erosion of

topsoil

due to poor

cultivation

practices.

GRASSLANDS AND SAVANNAS

EXAMPLES: PRAIRIES OF NORTH AMERICA • SOUTH AMERICAN PAMPAS • MEDITERRANEAN SCRUB • AUSTRALIAN GRASSLANDS • AFRICAN SAVANNA • ASIAN STEPPE ©

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The forests of the tropical latitudes range from

dry forest, to seasonal deciduous forest, to

evergreen lowland rainforest, to montane

cloud forest. Their soils are generally poor, with

most nutrients locked up in the abundant

vegetation that gives these forests their

structural complexity. Tropical forests support

numerous human cultures and are a rich

source of medicinal and agricultural products,

many as yet untapped. They also contain from

50 to 90 percent of all the world’s species,

some of which live in very limited ranges

within these vast habitats. More species are

being lost as these forests are cut down and

burned than in any other ecosystem in the

world. This large-scale deforestation also

releases greenhouse gases into the

atmosphere, affecting global climate.

TEMPERATE AND BOREAL FORESTS

ECOSYSTEM BENEFITS

SOURCE OF WOOD, FOOD, MEDICINES, AND OTHER PRODUCTS • BUFFER AGAINST FLOOD AND DROUGHT •STABILIZE LAND AND HELP PREVENT EROSION • HELP REGULATE RAINFALL • FILTER AIR POLLUTION ANDPRODUCE OXYGEN • PROTECT WATERSHEDS AND PURIFY WATER • ABSORB CARBON DIOXIDE AND HELP REGULATE CLIMATE • PROTECT FISH SPAWNING GROUNDS • FORM AND MAINTAIN FERTILITY OF SOILS


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old-growthold-growth

tempertemperate

forestsforests

are the mostare the most

endangered

forestsforests

in the world,in the world,

with leswith less than

10% remaining10% remaining

outside boreal

zones.

almost 30% almost 30%

of broad-leaof broad-leaved

trees and

15% 15%

of conifers of conifers

are suffering are suffering

“forest diebackforest dieback”

caused baused by pollution.ution.

TEMPERATE

BOREAL

TEMPERATE AND BOREAL FORESTS

EXAMPLES: EURASIAN AND NORTH AMERICAN BROAD-LEAVED DECIDUOUS, BOREAL CONIFER, AND MIXED FORESTS • EVERGREEN RAINFORESTS OF THE PACIFIC NORTHWEST, NEW ZEALAND, AND CHILE ©

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The forests of the tropical latitudes range from

dry forest, to seasonal deciduous forest, to

evergreen lowland rainforest, to montane

cloud forest. Their soils are generally poor, with

most nutrients locked up in the abundant

vegetation that gives these forests their

structural complexity. Tropical forests support

numerous human cultures and are a rich

source of medicinal and agricultural products,

many as yet untapped. They also contain from

50 to 90 percent of all the world’s species,

some of which live in very limited ranges

within these vast habitats. More species are

being lost as these forests are cut down and

burned than in any other ecosystem in the

world. This large-scale deforestation also

releases greenhouse gases into the

atmosphere, affecting global climate.

TROPICAL FORESTS

ECOSYSTEM BENEFITS

SOURCE OF WOOD, FOOD, MEDICINES, AND OTHER PRODUCTS • BUFFER AGAINST FLOOD AND DROUGHT •

HELP REGULATE RAINFALL • STABILIZE LAND AND HELP PREVENT EROSION • CYCLE NUTRIENTS • FILTER

AIR POLLUTION AND PRODUCE OXYGEN • PROTECT WATERSHEDS AND PURIFY WATER • ABSORB CARBON DIOX-

IDE AND HELP REGULATE CLIMATE PROTECT FISH SPAWNING GROUNDS


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about 72 acresabout 72 acres

of tropical forest

are lost

each minute each minute

as trees are cut

for firewood and for firewood and

timber, and timber, and

as land is

converted for

agriculture.

at currentt current

rates of tes of

destruction, destruction,

virtually no y no

tropical

forestsforests

will remain bwill remain by

the year 2030.the year 2030.

TROPICAL FORESTS

EXAMPLES: CENTRAL AMERICAN, AMAZONIAN, AND CONGO BASIN RAINFORESTS • SOUTHEAST ASIAN MONSOON FORESTS • ANDEAN CLOUD FORESTS • AUSTRALIAN SEASONAL FORESTS ©

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At the fringes of ocean coasts, wetlands such as

mangrove swamps, tidal flats, sea-grass beds,

estuaries, and salt marshes often line the shore.

In the warm, shallow waters off many tropical

coastlines, coral reefs grow, home to about 25

percent of all ocean species. These coastal

ecosystems act as buffers between land and

sea, protecting shorelines from storms,

erosion, and flooding. Coastal wetlands filter

and trap pollutants and sediments that could

smother corals and reduce the abundance of

coastal species. Coral reefs and coastal

wetlands are severely threatened by ocean

pollution; coastal development; siltation and

runoff from logging, sewage, agriculture, and

industry; and destructive fishing practices such

as dynamiting and cyanide poisoning.

CORAL REEFS ANDCOASTAL WETLANDS

ECOSYSTEM BENEFITS

NURSERY FOR MANY OCEAN SPECIES, INCLUDING FISH AND SHELLFISH • PROTECT AND STABILIZE SHORE-LINES • CONTROL EROSION • NESTING AND FEEDING GROUNDS FOR MANY SHOREBIRDS AND MIGRANTS •FILTER AND BREAK DOWN POLLUTION • CAPTURE NUTRIENTS, ENRICHING COASTAL WATERS • MANGROVESARE A SOURCE OF WOOD • CORAL REEFS ARE A SOURCE OF MEDICINES


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up to 10% of

the world’s reefs

have already been

ecologically

destroyed;

another 30%

are likely to

collapse by

the year 2020.

MANGROVES

SALT MARSH

CORAL REEF

SALT MARSH/MANGROVE

CORAL REEFS AND COASTAL WETLANDS

EXAMPLES: GREAT BARRIER REEF OF AUSTRALIA • FRINGING REEFS OF THE INDO-PACIFIC SEAS • CARIBBEAN MANGROVE FORESTS • ATLANTIC SALT MARSHES • EUROPEAN SEA-GRASS MEADOWS ©

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True deserts receive less than 100 millimeters

of rain per year. Some deserts are vast stretches

of sand with little or no life, except in

occasional oases. Others, however, support a

rich variety of species that have structural or

behavioral adaptations for coping with scarcity

of water or the harsh temperatures, which

fluctuate widely between scorching days and

cold nights. For instance, many plants store

water in their succulent stems, have extensive

root systems, or grow or flower only during a

brief period following rain. Animals such as

rodents, snakes, lizards, scorpions, and insects

tend to burrow underground or be active only

at night. Some, like the gemsbok antelope of

southern Africa, can survive without any

surface moisture, obtaining all their water

from plants.

DESERTS

ECOSYSTEM BENEFITS

THE LAST REMAINING UNSPOILED REGIONS ON EARTH • TRADITIONALLY INHABITED BY NOMADIC HERDS-

MEN • HOME TO SPECIES UNIQUELY ADAPTED TO EXTREME ENVIRONMENTS


COVERAGE

4% OF THE EARTH’S SURFACE

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deserts are

expanding

every year

as a result of

climate changes

and inefficient

agricultural

practices in

adjoining

regions.

DESERTS

EXAMPLES: AFRICAN SAHARA AND NAMIB DESERTS • GOBI DESERT OF ASIA • AUSTRALIAN GREAT SANDY DESERT • NORTH AMERICAN GREAT BASIN • ATACAMA DESERT OF SOUTH AMERICA ©

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Less than one-tenth of 1 percent of the earth’s

water is in the wetlands (which include bogs,

fens, swamps, and marshes), lakes, and rivers

from which we draw much of our fresh water.

Nevertheless, these freshwater systems are

home to an immense variety of life, including

more than 40 percent of known fishes and

many shellfish, amphibians, and insects.

Lakes, in particular, are home to many endemic

species — those restricted to a certain place and

found nowhere else. Many of these species are

vulnerable to introduced alien species.

Freshwater habitats are also threatened by

siltation and polluted runoff from agriculture,

industry, deforestation, and sewage; damming

and water diversions; and filling or drainage of

wetlands.

FRESHWATER WETLANDS,RIVERS, AND LAKES

ECOSYSTEM BENEFITS

REGULATE QUALITY AND AVAILABILITY OF FRESH WATER • FILTER AND DILUTE POLLUTION • CONTROL ERO-SION AND RETAIN NUTRIENTS • PROVIDE FLOOD CONTROL • SUPPLY HYDROELECTRIC POWER • SERVE ASTRANSPORTATION ROUTE • SOURCE OF FOOD AND ESSENTIAL DRINKING WATER • SPAWNING, NURSERY, ANDFEEDING AREAS FOR FISH, AMPHIBIANS, INVERTEBRATES, AND MIGRATORY BIRDS


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as human as human

population and

needs grow,

supplies of

usable water

are shrinking.

more than 20% more than 20%

of the worldof the world’s s

poppopulaulation tion

does not hadoes not have ve

accesaccess to s to

safe drinking afe drinking

wawater.ter.

at least t least

20% of 20% of

the worldthe world’s

freshwafreshwater fishter fish

are currentlare currently y

at risk.t risk.

FRESHWATER WETLANDS, RIVERS, AND LAKES

EXAMPLES: OKAVANGO DELTA • SOUTH AMERICAN PANTANAL • EVERGLADES • GREAT LAKES •LAKE VICTORIA • GANGES AND RHINE RIVERS • OKEFENOKEE SWAMP • ALASKAN MUSKEG ©

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Covering almost three-quarters of the earth’s

surface, the salty waters of seas and oceans are

home to many bacteria and protoctists, as well

as all but one of the major groups (phyla) of

animals — half of which, in fact, live

exclusively in these marine waters. Marine

ecosystems range from shallow continental

shelves, to open oceans, to the deep seas.

Hydrothermal vents emerging from some

regions of the ocean floor support ecosystems

of unique, bizarre species, all of which obtain

their energy from bacteria that can live off

these plumes of boiling, sulfurous water.

Marine environments are being increasingly

polluted by atmospheric fallout, oil from

shipping and other sources, and disposal of

industrial and other human wastes.

OCEANS

ECOSYSTEM BENEFITS

REGULATE QUALITY AND AVAILABILITY OF FRESH WATER • FILTER AND DILUTE POLLUTION • CONTROL ERO-SION AND RETAIN NUTRIENTS • PROVIDE FLOOD CONTROL • SUPPLY HYDROELECTRIC POWER • SERVE ASTRANSPORTATION ROUTE • SOURCE OF FOOD AND ESSENTIAL DRINKING WATER • SPAWNING, NURSERY, ANDFEEDING AREAS FOR FISH, AMPHIBIANS, INVERTEBRATES, AND MIGRATORY BIRDS


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70% OF THE EARTH’S SURFACE

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oceans areoceans are

threathreatened btened by

pollpollution andution and

dumping ofdumping of

wastes; over-wastes; over-

exploitexploitation of tion of

fisheries; andfisheries; and

introduced alien introduced alien

species.species.

the cthe catch in 13ch in 13

of the worldof the world’s

15 major fishing15 major fishing

regions has regions has

declined in declined in

recent years.recent years.

OCEANS

EXAMPLES: ATLANTIC, PACIFIC, ARCTIC, AND INDIAN OCEANS • BERING, MEDITERRANEAN, AEGEAN, RED, CARIBBEAN, AND BALTIC SEAS • HUDSON AND CHESAPEAKE BAYS ©

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Islands range in size from tiny rocks a few feet

across to gigantic semicontinents such as

Greenland. Often remote from the continental

mainland, islands are laboratories of evolution,

frequently with many endemic species — those

found nowhere else. Because of the fixed

boundaries within which they live, island

plants and animals are particularly vulnerable

to extinction through overexploitation and

disturbance of their habitats. Moreover, since

many island species have evolved without

natural predators, they become helpless

victims of alien species and diseases

introduced by humans. Global warming could

also greatly threaten islands, drowning their

coasts under the ensuing rises in sea level.

ISLANDS

ECOSYSTEM BENEFITS

HOME TO DIVERSE, UNIQUE SPECIES OF ANIMALS AND PLANTS


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approximaapproximately

75% of all75% of all

recorded animal recorded animal

extinctions have

taken place

on oceanic

islands.

ISLANDS

EXAMPLES: HAWAIIAN AND GALÁPAGOS ISLANDS • CUBA • NANTUCKET • ICELAND •SICILY • MADAGASCAR • INDONESIAN ARCHIPELAGO • JAPAN • NEW ZEALAND • ALEUTIAN ISLANDS ©

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