Download CHAPTER 6: HUMANS IN THE BIOSPHERE

CHAPTER 6: HUMANS IN THE BIOSPHERE
6.1: A CHANGING LANDSCAPE
HUMANS IN THE BIOSPHERE
 IN 1778, EUROPEANS ARRIVED ON THE
ISLAND CHAIN OF HAWAII.
 THEY CHANGED THE ISLANDS BY
INTRODUCING RANCHING, PREDATORS, AND
DISEASE.
 LARGE AREAS HAVE BEEN PAVED FOR
HOUSING SCHOOLS AND INDUSTRY; NATIVE
HAWAIIAN SPECIES ARE GONE
EARTH AS AN ISLAND
ALL ORGANISMS THAT LIVE ON EARTH SHARE
A LIMITED RESOURCE BASE
 HUMAN POPULATION IS INCREASING; OUR
PLANET IS NOT

HUMAN ACTIVITIES
INDUSTRY AND TECHNOLOGY GIVE HUMANS A
STRONG ADVANTAGE IN COMPETING FOR
FOOD, ENERGY, AND SPACE
 HUMANS ARE THE MOST IMPORTANT SOURCE
OF ENVIRONMENTAL CHANGE ON THE
PLANET

FOUR ACTIVITIES THAT HAVE TRANSFORMED
THE BIOSPHERE
1.
2.
3.
4.
HUNTING AND GATHERING
AGRICULTURE
INDUSTRY
URBAN DEVELOPMENT
HUNTING AND GATHERING
THIS USED TO BE THE PRIMARY MEANS OF
SURVIVAL
 PEOPLE LIVED IN SMALL GROUPS
 HUNTING AND GATHERING CAUSED ONE OF
THE MAJOR MASS EXTINCTIONS OF LARGE
ANIMALS (WOOLY MAMMOTHS, GIANT
SLOTHS, AND SABERTOOTH CATS)

AGRICULTURE (FARMING)
THE SPREAD OF AGRICULTURE WAS
IMPORTANT BECAUSE IT PROVIDED PEOPLE
WITH A DEPENDABLE SUPPLY OF FOOD
 HUMANS GATHERED IN LARGER
SETTLEMENTS (TOWNS AND CITIES) AND
DEVELOPED GOVERNMENT AND LAWS.

DOMESTICATION OF ANIMALS
(SHEEP, GOATS, COWS, PIGS,
HORSES, DOGS) SUPPLIED
HUMANS WITH MILK, WOOL,
ETC.
 OVERGRAZING CHANGED
GRASSLAND ECOSYSTEMS,
ERODED SOIL, AND PUT LARGE
DEMANDS ON WATER SUPPLIES
 TRADITIONAL AGRICULTURE
(1450-1700) ALLOWED FOR THE
EXCHANGE OF FOODS AROUND
THE WORLD TO BEGIN

1800’S: IRRIGATION, NEW CROP
VARIETIES, AND FARM MACHINES
HELPED FARMERS INCREASE THEIR
YIELDS TREMENDOUSLY
 GREEN REVOLUTION:
INTRODUCED NEW FARMING
PRACTICES THAT GREATLY
INCREASED THE YIELDS OF RICE,
WHEAT, ETC.

STRATEGIES OF THE GREEN REVOLUTION

MONOCULTURE: LARGE FIELDS ARE CLEARED,
PLOWED AND PLANTED WITH A SINGLE CROP
YEAR AFTER YEAR
FARMERS RELY ON IRRIGATION, CHEMICAL
FERTILIZERS, AND PESTICIDES
 THE BENEFIT TO HUMANS FROM THE GREEN
REVOLUTION IS NEW FARMING PRACTICES
INCREASED FOOD PRODUCTION AND PREVENTED
FOOD SHORTAGES

PROBLEMS WITH THE GREEN REVOLUTION
1.
2.
3.
4.
INTENSIVE FARMING CAN DEPLETE ENERGY
AND WATER SUPPLIES
MONOCULTURE ALLOWS PESTS TO
REPRODUCE QUICKLY
PESTICIDES CARRY HARMFUL CHEMICALS
FERTILIZERS CAN INTERFERE WITH FOOD
WEBS AND BIOGEOCHEMICAL CYCLES
INDUSTRIAL GROWTH AND URBAN
DEVELOPMENT
HUMAN SOCIETY WAS TRANSFORMED BY THE
INDUSTRIAL REVOLUTION
 MOST ENERGY NEEDED TO PRODUCE POWER
CAME FROM FOSSIL FUELS (COAL, OIL,
NATURAL GAS)


INDUSTRIAL PROCESSES POLLUTE AIR,
WATER, AND SOIL
6-2: RENEWABLE AND NONRENEWABLE
RESOURCES

A RESOURCE IS SOMETHING THAT CAN BE
USED TO TAKE CARE OF A NEED

A COMMON RESOURCE IS AN ENVIRONMENTAL
RESOURCE OWNED BY MANY PEOPLE IN
COMMON –
like the atmosphere or community pool

“TRAGEDY OF THE COMMONS”: ANY
RESOURCE THAT IS OPEN TO EVERYONE (AIR,
OCEANS) WILL EVENTUALLY BE DESTROYED
BECAUSE EVERYONE CAN USE IT, BUT NO
ONE IS RESPONSIBLE FOR PRESERVING IT

NIMBY - _______________________________
TWO TYPES OF ENVIRONMENTAL RESOURCES
1.
2.
RENEWABLE: THEY CAN BE REGENERATED
AND ARE REPLACEABLE (TREES); THEY CAN
BE LIMITED THOUGH
NON-RENEWABLE: CANNOT BE
REPLENISHED BY NATURAL PROCESSES;
ONCE THEY ARE USED, THEY ARE GONE
FOREVER (FOSSIL FUELS)
SUSTAINABLE USE: A WAY OF USING
NATURAL RESOURCES AT A RATE THAT DOES
NOT DEPLETE THEM
***UNLESS SUSTAINABLE STRATEGIES ARE USED,
HUMAN ACTIVITIES CAN / WILL
DAMAGE/DEPLETE RESOURCES

LAND RESOURCES

IF MANAGED PROPERLY, SOIL IS RENEWABLE. IF
NOT, IT WILL BE PERMANENTLY DAMAGED.

FERTILE SOIL: BEST FOR FOOD CROPS TO
GROW; CONTAINS A MIXTURE OF HUMUS, SAND,
CLAY AND ROCK

PLOWING: REMOVES ROOTS THAT HOLD SOIL IN
PLACE SOIL EROSION = THE WEARING AWAY
OF SURFACE SOIL BY WATER AND WIND

DESERTIFICATION: COMBINATION OF
FARMING, OVERGRAZING AND DROUGHT
THAT TURNS PRODUCTIVE AREAS INTO
DESERTS
OCEAN RESOURCES
*VALUABLE FOR FOOD
*FISHING HAS INCREASED, BUT FISH STOCKS IN
FISHERIES ARE BEING HARVESTED FASTER
THAN THEY CAN REPRODUCE=OVERFISHING
SUSTAINABLE USE OF FISHERIES

LIMIT THE CATCH OF FISH POPULATIONS:
THE PROBLEM IS THAT OPEN OCEAN WATERS
ARE OUTSIDE THE CONTROL OF ANY ONE
SINGLE COUNTRY.
AN EXAMPLE OF A COMMON RESOURCE THAT
EVERYONE WANTS BUT NO ONE HAS INCENTIVE
TO PROPERLY MANAGE – Tragedy of the
Commons!!

AQUACULTURE: FARMING OF AQUATIC
ORGANISMS
 GOOD
BECAUSE IT PRODUCES ANIMAL PROTEIN
 IF IT ISNT MANAGED, THIS POLLUTES WATER
WITH FISH WASTES
AIR RESOURCES

SMOG: MIXTURE OF CHEMICALS THAT OCCURS
AS A GRAY-BROWN HAZE IN THE ATMOSPHERE;
IT IS A COMBINATION OF SMOKE AND FOG,
MOSTLY DUE TO AUTOMOBILE EXHAUSTS AND
INDUSTRY EMISSIONS

POLLUTANT: HARMFUL MATERIAL THAT CAN
ENTER THE BIOSPHERE THROUGH THE LAND,
AIR, OR WATER
**BURNING OF FOSSIL FUELS SUCH AS
NITRATES, SULFATES, AND PARTICULATES**



PARTICULATES: MICROSCOPIC
PARTICLES OF ASH AND DUST THAT
CAUSE HEALTH PROBLEMS
COMBUSTION: RELEASES ACIDIC
GASES THAT COMBINE WITH WATER
VAPOR, to make NITRIC AND
SULFURIC ACIDS -- ACID RAIN.
ACID RAIN KILLS PLANTS, CHANGES
SOIL CHEMISTRY, AND RELEASES
MERCURY FROM THE SOIL WHICH IS
TOXIC.
WATER RESOURCES
OVERALL, WATER IS A RENEWABLE
RESOURCE. FRESHWATER IS LIMITED AS A
RESOURCE.
 POLLUTION THREATENS WATER SUPPLIES:

WATER POLLUTION!!! 
 OIL
SPILLS
 IMPROPER DISPOSAL OF CHEMICALS LEADS TO
THEIR SEEPAGE INTO STREAMS AND RIVERS
 WASTE DISCARDED ON LAND SEEPS INTO SOIL
AND ENTERS GROUNDWATER SUPPLIES
 DOMESTIC SEWAGE CONTAINS NITROGEN AND
PHOSPHORUS COMPOUNDS THAT ENCOURAGES
GROWTH OF ALGAE AND BACTERIA IN AQUATIC
HABITATS
 SEWAGE ALSO SPREADS DISEASE AMONG HUMANS
AND ANIMALS

SUSTAINABLE USE=WATER CONSERVATION
6-3: BIODIVERSITY
VARIETY IS ALSO KNOWN AS
DIVERSITY.
BIODIVERSITY: THE SUM OF THE
GENETICALLY BASED VARIETY OF ALL
ORGANISMS IN THE BIOSPHERE
 ECOSYSTEM DIVERSITY: VARIETY OF
HABITATS, COMMUNITIES, AND
ECOLOGICAL PROCESSES IN THE
LIVING WORLD


SPECIES DIVERSITY: NUMBER OF DIFFERENT
SPECIES IN THE BIOSPHERE

GENETIC DIVERSITY: SUM OF ALL DIFFERENT
FORMS OF GENETIC INFORMATION CARRIED
BY ALL ORGANISMS LIVING ON EARTH
BIODIVERSITY IS ONE OF EARTH’S GREATEST
NATURAL RESOURCES

SPECIES HAVE PROVIDED US WITH:
 FOODS
 MEDICINES
 ANTICANCER
DRUGS
 PAINKILLERS
 ANTIBIOTICS
 HEART
DRUGS
 ANTIDEPRESSANTS
THREATS TO BIODIVERSITY
HUMAN ACTIVITY IS THE NUMBER ONE
THREAT!
 WE ALTER HABITATS, HUNT SPECIES TO
EXTINCTION, INTRODUCE TOXIC COMPOUNDS
INTO FOOD WEBS, AND INTRODUCE FOREIGN
SPECIES TO A NEW ENVIRONMENT

EXTINCTION: OCCURS WHEN A SPECIES
DISAPPEARS FROM ALL OR PART OF ITS
RANGE
 ENDANGERED SPECIES: SPECIES WHOSE
POPULATION SIZE IS DECLINING AND IN
DANGER OF EXTINCTION

DEMAND FOR WILDLIFE PRODUCTS
HUNTING HAS CAUSED
EXTINCTION FOR MANY SPECIES
 TODAY, ENDANGERED SPECIES
ARE PROTECTED FROM
HUNTING IN THE U.S.
 AFRICA, SOUTH AMERICA, AND
ASIA STILL ALLOW HUNTING OF
ANIMALS FOR FOOD, FUR,
HIDES, ETC.

POLLUTION: SERIOUS PROBLEM
THREATENING BIODIVERSITY; OCCURS WHEN
TOXIC COMPOUNDS ACCUMULATE IN TISSUES
OF ORGANISMS (EX. DDT)
1. DDT WAS THOUGHT TO BE “PERFECT”REMAINS ACTIVE FOR A LONG TIME, KILLS
MANY DIFFERENT INSECTS, AND WAS CHEAP
2. WHEN SPRAYED, DRAINED INTO WATER
SUPPLIES

DDT

DDT IS:
1.
NON-BIODEGRADABLE: NOT BROKEN DOWN
IN NATURE
2.
NOT ELIMINATED FROM THE BODIES OF
ORGANISMS AS THEY PICK IT UP
TWO PROPERTIES THAT MAKES DDT
HAZARDOUS
DDT IS CONCENTRATED AND STORED IN
AQUATIC PLANTS/ALGAEHERBIVORES EAT
PLANTS AND GET 10 TIMES THE
CONCENTRATION THE PLANTS
HADCARNIVORES EAT HERBIVORES AND
DDT IS CONCENTRATED EVEN
MORE=PROCESS OF BIOLOGICAL
MAGNIFICATION

BIOLOGICAL MAGNIFICATION:
CONCENTRATIONS OF A HARMFUL SUBSTANCE
INCREASES IN ORGANISMS AT HIGHER
TROPHIC LEVELS IN A FOOD CHAIN/WEB
BY THE 1970’S, DDT WAS BANNED IN THE
U.S.
 RACHEL CARSON WROTE A BOOK IN 1962,
TITLED “SILENT SPRING” WHICH EXPLAINED
THE RESULTS OF USING THE PESTICIDE DDT.

INTRODUCED SPECIES
INVASIVE SPECIES: PLANTS
AND ANIMALS THAT HAVE
MIGRATED TO PLACES
WHERE THEY ARE NOT
NATIVE
 POPULATIONS EXPLODE
BECAUSE THE NEW HABITAT
LACKS PARASITES AND
PREDATORS

6-4: CHARTING A COURSE FOR THE FUTURE

1.
2.
MANY BIOLOGISTS ARE CONCERNED ABOUT
THE BIOLOGICAL EFFECTS OF TWO TYPES OF
GLOBAL CHANGE:
THE THINNING OR DEPLETION OF THE
OZONE LAYER
GLOBAL WARMING
OZONE DEPLETION (O3)
OZONE LAYER IS 20-50 KM ABOVE EARTH’S
SURFACE
 OZONE AT GROUND LEVEL IS A POLLUTANT
 OZONE LAYER ABSORBS UV RADIATION FROM
SUNLIGHT BEFORE IT REACHES EARTH’S
SURFACE

EXPOSURE TO UV RADIATION CAUSES:
SUNBURN
 CANCER
 DAMAGE TO EYES
 DECREASED RESISTANCE TO DISEASE

*THE OZONE LAYER SERVES AS A GLOBAL
SUNSCREEN BECAUSE IT SHIELDS THE
BIOSPHERE FROM UV LIGHT
1970’S: “HOLE” DISCOVERED IN OZONE
LAYER OVER ANTARCTICA
 1995: OZONE HOLE LARGE ENOUGH TO
EXPOSE PARTS OF THE US TO HIGH LEVELS
OF UV


CFC’S: CHLOROFLOUROCARBONS: ACT AS
CATALYSTS THAT ENABLE UV LIGHT TO BREAK
APART OZONE MOLECULES
GLOBAL WARMING
GLOBAL WARMING IS AN INCREASE IN THE
AVERAGE TEMPERATURE OF THE BIOSPHERE
 TEMPERATURES BETWEEN 1980 AND 2000
ROSE AT A FASTER RATE THAN DURING THE
PREVIOUS 100 YEARS
 1990’S WERE THE HOTTEST DECADE EVER
RECORDED

CAUSES OF GLOBAL WARMING
1.
HUMAN ACTIVITIES HAVE
ADDED CARBON DIOXIDE AND
OTHER GREENHOUSE GASES
SUCH AS METHANE TO THE
ATMOSPHERE.
2.
GLOBAL ATMOSPHERE
GREENHOUSE RETAINS MORE
HEAT.
3.
THE BURNING OF FOSSIL FUELS ADDS
CARBON DIOXIDE TO THE ATMOSPHERE, AS
DOES CUTTING DOWN AND BURNING
FORESTS.
4.
NATURAL VARIATIONS IN CLIMATE:AVERAGE
GLOBAL SURFACE TEMPERATURE WILL
INCREASE BY 1-2 DEGREES CELSIUS BY 2050
IF GLOBAL WARMING CONTINUES AT CURRENT
RATES, THE POLAR ICE CAPS WILL CONTINUE TO
MELT AND SEA LEVELS COULD RAISE ENOUGH TO
FLOOD SOME LOW-LYING COASTAL AREAS
 STORMS COULD BECOME MORE FREQUENT AND
SEVERE
 MORE SERIOUS DROUGHTS IN NORTH AMERICA
 ABUNDANCE OF DISEASE CARRYING SPECIES
COULD INCREASE

HOW DO WE MAINTAIN A HEALTHY BIOSPHERE?
USE RESOURCES WISELY
 RECYCLE MATERIALS
 CONSERVE ENERGY
 BETTER INSULATE HOMES AND OFFICES
 BUY FUEL EFFICIENT CARS

*STUDY FOR YOUR TEST!!!