Transcript FOREST BIOMES

FOREST BIOMES
TROPICAL, TEMPERATE AND
BOREAL
WHAT IS A FOREST?
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UNDISTURBED AREAS WITH
MODERATE TO HIGH AVERAGE
ANNUAL PRECIPITATION WITH
VARIOUS SPECIES OF TREES AND
SMALLER FORMS OF VEGETATION
TROPICAL RAINFORESTS
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A TYPE OF BROADLEAF EVERGREEN FOREST
NEAR THE EQUATOR WHERE HOT,
MOISTURE-LADEN AIR RISES AND DUMPS ITS
MOISTURE
WORLD’S LARGEST TROPICAL RAINFOREST IS
IN THE AMAZON RIVER BASIN IN SOUTH
AMERICA
HIGH HUMIDITY, DAILY HEAVY RAINFALL
AND WARM ANNUAL TEMPERATURES
BIOLOGICAL DIVERSITY
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HIGHEST DIVERSITY ON EARTH
DIVERSE LIFE FORMS OCCUPY A
VARIETY OF SPECIALIZED NICHES IN
DISTINCT LAYERS, BASED MOSTLY ON
THEIR NEED FOR SUNLIGHT
R.F. COVER 2% OF EARTH’S SURFACE
BUT ARE HABITATS FOR 50-80% OF
EARTH’S TERRESTRIAL SPECIES
LAYERS OF THE RAINFOREST
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EMERGENT LAYER – TOP LAYER, OCCUPIED BY THE
TALLEST TREES
CANOPY – NEXT TO TOP LAYER, ABUNDANT
SHELTER AND SUPPLIES OF LEAVES, FLOWERS AND
FRUITS; MUCH OF THE ANIMAL LIFE IS HERE
UNDERSTORY – SMALL TREES ADAPTED TO LOW
LIGHT
SHRUB LAYER – SHRUBS AND SHORT PLANTS
ADAPTED TO EVEN LESS LIGHT
GROUND LAYER-OPEN AND FREE OF VEGETATION
PLANT ADAPTATIONS
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LIANAS – CLIMBING VINES, ROOTED IN
THE SOIL, WIND UPWARD AROUND THE
TRUNKS OF LARGER TREES INTO THE
CANOPY
EPIPHYTES – ORCHIDS, BROMELIADS
ATTACH THEMSELVES TO THE TRUNKS
AND BRANCHES OF CANOPY TREES
PLANT ADAPTATIONS
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UNDERSTORY & SHRUB LAYER PLANTS
– PHILODENDRONS – USE HUGE, DARK
GREEN LEAVES TO CAPTURE ENOUGH
SUNLIGHT
ROOTS OF EVEN LARGE TREES TEND
TO BE SHALLOW AND SPREAD OUT
BUTTRESSES – LARGE BULGES AT BASE
OF TREE FOR SUPPORT
COEXISTENCE
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STRATIFICATION OF SPECIALIZED
PLANT AND ANIMAL NICHES
ENCOURAGES BIOLOGICAL DIVERSITY
PRESENCE OF THESE SPECIALIZED
NICHES ENABLES SPECIES TO AVOID
OR MINIMIZE COMPETITION FOR
RESOURCES AND INCREASES THE
COEXISTENCE OF A GREAT VARIETY
OF SPECIES (BIODIVERSITY)
RAINFOREST NUTRIENTS
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NUTRIENTS ARE NOT STORED IN THE
SOIL
NUTRIENTS ARE STORED IN THE
BIOMASS OF ITS LIVING ORGANISMS
LIVING PLANTS RAPIDLY TAKE UP THE
NUTRIENTS FROM THE DECOMPOSING
ORGANIC MATTER
TROPICAL DECIDUOUS
FORESTS
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TROPICAL MONSOON FORESTS OR
TROPICAL SEASONAL FORESTS
WARM YEAR-ROUND
MOST RAIN COMES DURING A
MONSOON SEASON FOLLOWED BY A
LONG DRY SEASON
CANOPY IS LOWER
TROPICAL DECIDUOUS
FORESTS
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CONTAIN A MIXTURE OF DECIDUOUS
TREES AND DROUGHT-TOLERANT
EVERGREEN TREES
TEMPERATE DECIDUOUS
FORESTS
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GROW IN AREAS WITH MODERATE
AVERAGE TEMPERATURES THAT
CHANGE SIGNIFICANTLY WITH THE
SEASON
LONG WARM SUMMERS
COLD BUT NOT TOO SEVERE WINTERS
ABUNDANT PRECIPITATION
TEMPERATE DECIDUOUS
FORESTS
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DOMINATED BY A FEW SPECIES OF
BROADLEAF DECIDUOUS TREES SUCH
AS OAK, HICKORY, MAPLE, POPLAR AND
SYCAMORE
SURVIVE COLD WINTERS BY DROPPING
THEIR LEAVES IN THE FALL AND
BECOMING DORMANT
TEMPERATE DECIDUOUS
FORESTS
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LOW RATE OF DECOMPOSITION SO
FOREST ACCUMULATES A THICK LAYER
OF SLOWLY DECAYING LEAF LITTER
THAT IS A STOREHOUSE OF NUTRIENTS
RICHER DIVERSITY OF PLANT LIFE AT
GROUND LEVEL DUE TO SUNLIGHT
REACHING THE GROUND
TEMPERATE DECIDUOUS
FORESTS
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DOMINANT MAMMAL SPECIES IS THE
WHITE-TAILED DEER, SQUIRRELS,
RABBITS, POSSUMS, RACCOONS AND
MICE
EVERGREEN CONIFEROUS
FORESTS
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ALSO CALLED BOREAL FORESTS &
TAIGAS
FOUND JUST SOUTH OF THE ARCTIC
TUNDRA IN NORTHERN REGIONS
ACROSS NORTH AMERICA, ASIA &
EUROPE
CHARACTERISTICS
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WINTERS ARE LONG, DRY AND
EXTREMELY COLD
IN THE NORTHERNMOST TAIGA,
SUNLIGHT AVAILABLE 6-8 HOURS EACH
DAY
SUMMERS ARE SHORT, MILD TO WARM
TEMPERATURES
SUN SHINES 19 HOURS A DAY
BOREAL FORESTS
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DOMINATED BY A FEW SPECIES OF
EVERGREEN CONIFER TREES SUCH AS
SPRUCE, FIR, CEDAR, HEMLOCK AND
PINE
LOW PLANT DIVERSITY BECAUSE FEW
SPECIES CAN SURVIVE THE WINTERS
WHEN SOIL MOISTURE IS FROZEN
BOREAL FORESTS
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DECOMPOSITION IS SLOW DUE TO LOW
TEMPERATURES, WAXY COATING ON
THE NEEDLES AND HIGH ACIDITY
VARIETY OF WILDLIFE
MOSTLY SEED-EATERS – SQUIRRELS
INSECT HERBIVORES
LARGER BROWSERS – ELK AND MOOSE
BOREAL FORESTS
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PREDATORS INCLUDE WOLVES,
WOLVERINES, GRIZZLY BEARS AND
BLACK BEARS
TEMPERATE RAIN FORESTS
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COASTAL CONIFEROUS RAINFORESTS
FOUND IN SCATTERED COASTAL
TEMPERATE AREAS WITH AMPLE
RAINFALL OR MOISTURE FROM DENSE
OCEAN FOGS
TEMPERATE RAIN FOREST
CHARACTERISTICS
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COAST OF NORTH AMERICA FROM
CANADA TO NORTHERN CALIFORNIA
DOMINATED BY STANDS OF LARGE
CONIFERS SUCH AS SITKA SPRUCE,
DOUGLAS FIR AND REDWOODS
WINTERS ARE MILD
SUMMERS ARE COOL
WHAT IMPACTS DO HUMAN
ACTIVITIES HAVE ON FOREST
ECOSYSTEMS?
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CLEARING AND DEGRADATION OF
TROPICAL RAINFORESTS FOR TIMBER,
GRAZING LAND AND AGRICULTURE
LEADS TO SEVERE EROSION
CLEARING OF TEMPERATE DECIDUOUS
FORESTS IN EUROPE, ASIA AND NORTH
AMERICA FOR TIMBER CROPLAND AND
URBAN DEVELOPMENT
HUMAN IMPACT
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IN NORTH AMERICA, ABOUT 99.9% OF THE
ORIGINAL STANDS HAVE BEEN CLEARED
CLEARING OF LARGE AREAS OF EVERGREEN
CONIFEROUS FORESTS BY LOGGERS IN
NORTH AMERICA, FINLAND, SWEDEN AND
CANADA
BECAUSE OF THE COLD, CONIFEROUS TREES
TAKE A LONG TIME TO RECOVER
MOUNTAIN BIOMES
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COVER 20% OF EARTH’S SURFACE
PLACES WHERE DRAMATIC CHANGES
IN ALTITUDE, CLIMATE, SOIL AND
VEGETATION TAKE PLACE OVER A
VERY SHORT DISTANCE
EACH 300 FOOT CHANGE IN
ELEVATION IS EQUIVALENT TO A 62
MILE CHANGE IN LATITUDE
MOUNTAIN BIOMES
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ISLANDS OF BIODIVERSITY – MANY
FREE-STANDING MOUNTAINS
CONTAIN ENDEMIC SPECIES FOUND
NOWHERE ELSE ON EARTH
ALSO SANCTUARIES FOR ANIMAL
SPECIES DRIVE FROM LOWLAND AREAS
DUE TO DEVELOPMENT
ANTARCTICA IS THE MOST
MOUNTAINOUS OF ALL CONTINENTS
MOUNTAIN BIOMES
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ALSO CONTAIN THE MAJORITY OF THE
WORLD’S FORESTS WHICH CONTAIN
MOST OF THE WORLD’S BIODIVERSITY
MOUNTAINS PLAY A CRITICAL ROLE IN
THE HYDROLOGIC CYCLE BY
GRADUALLY RELEASING MELTING ICE,
SNOW AND WATER STORED IN THE
SOILS AND VEGETATION OF
MOUNTAINSIDES TO SMALL STREAMS
IMPACT OF HUMAN
ACTIVITIES ON MOUNTAIN
ECOSYSTEMS
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RAPIDLY INCREASING POPULATIONS
IN DEVELOPING COUNTRIES FORCES
LANDLESS PEOPLE TO TRY TO SURVIVE
IN THE MOUNTAINS
INCREASED HARVESTING OF TIMBER
AND MINERAL RESOURCES
DAMMING OF RIVERS IN MOUNTAINS
FOR HYDROELECTRIC POWER
IMPACT
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ENVIRONMENTAL DEGRADATION
FROM RECREATIONAL ACTIVITIES
INCREASED AIR POLLUTION
CHANGES IN CLIMATE AND LEVELS OF
UV RADIATION