chapter 4 section 3 sc b-6: students will demonstrate an understanding of the interrelationships...
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CHAPTER 4 SECTION 3SC B-6: STUDENTS WILL
DEMONSTRATE AN UNDERSTANDING OF THE INTERRELATIONSHIPS
AMONG ORGANISMS & THE BIOTIC & ABIOTIC COMPONENTS OF THEIR
ENVIRONMENT
BIOMES
Biomes
major life zones characterized by vegetation type (in terrestrial biomes) or by the physical environment (in aquatic biomes)
Climographs
show that temp & precipitation are correlated with biomes
because other factors also play a role in biome location: biomes can overlap
General Features of Terrestrial Biomes
most named for major physical or climatic features & for their predominant vegetation
each biome also characterized by:microorganismsfungianimalsall adapted to that particular environment
Biome Species Composition
varies w/in each biome ex: eastern part of one large lake may have
different water bird than western portion
Tropical Forest
Distribution: equatorial & subequatorialPrecipitation:
Tropical Rainforest: constant, 200 -400 cm/yr
Tropical Dry Forest: seasonal, 150 – 200 cm/yr
Temperature: high all yr, average 25 – 29°C , little
seasonal variation
Tropical Forest Plants
Tropical Rainforest see all layers,
some with 2 layers of subcanopy trees
broadleaf evergreen trees dominate
epiphytes (air plants) & orchids typically cover trees
Tropical Dry Forest see fewer layers drop leaves during
dry season commonly have
thorny shrubs & succulent plants
Tropical Forest: Animals
millions of species5 – 30 million undiscovered species of
insects, spiders, other arthropodshighest animal diversity than anywhere else
on Earthall adapted to vertically layered environment
DESERT
Distribution: occur in bands near 30° N & S latitude or in
interior of continentsPrecipitation:
low & variable; <30 cm/yrTemperature :
variable seasonally & daily hot desert: max T may > 50°C dry desert: low T may < -30°C
Desert Plants
see low, widely scattered vegetation see more bare ground than other terrestrial
biomessucculents
cacti euphorbs
deeply rooted shrubs & herbs grow during brief rainy periods
Desert Plants
Adaptations: heat & desiccation tolerance water storage reduced leaf surface area CAM photosynthesis physical defenses:
spines chemical defenses:
toxins in leaves of shrubs
Desert Animals
Common animals:SnakesLizardsScorpionsAntsBeetlesBirds: migratory & residentseed-eating Rodents
Desert Animal Adaptations
many species are nocturnalwater conserved in variety of ways:
only water some get is by metabolizing carbohydrates water + carbon dioxide
SAVANNA
Distribution: equatorial & subequatorial
Precipitation: seasonal rainfall 30 – 50 cm/yr dry season can last 8 – 9 months
Temperature : warm year-round: 24 – 29 °C more seasonal variation than tropical forests
Savanna Animals
dominant herbivores are insects especially termites
large herbivores migrate toward thicker vegetation & watering holes during dry season
Chaparral
also called mattoral (Spain & Chile) garigue & maquis (southern France) fynbos (South Africa)
Chaparral
Distribution: midlatitude coastal regions
Precipitation: highly seasonal (rainy winters, dry summers) averages 30 – 50 cm/yr
Temperature : fall, winter, spring are cool (10 – 12°C) summer can get > 40°C
Chaparral Plants
dominated by shrubs, small trees, variety of grasses & herbs
plant diversity high though some species found only in very limited areas
adaptations to: drought: tough evergreen leaves fire:
herb seeds only germinate after hot fire roots are fire resistant (plants re-sprout quickly)
Chaparral Animals
natives include: browsers (deer,
goats) high diversity of
small mammals many amphibians,
birds, reptiles, insects
Temperate Grassland
also called:veldts (South Africa)puszta (Hungary)pampas (Argentina & Uruguay)steppes (Russia)plains & prairies (North America)
Temperate Grassland
Precipitation: highly seasonal: dry winters/wet summers averages vary between 30 – 100 cm/yr periodic drought is common
Temperature : winters cold (< -10°C) summers moderately hot ( 30°C)
Temperate Grasslands: Plants
dominant plants are grasses & forbs some grasses 2 m high
many adapted to survive periodic drought & fires
grazing by herbivores helps prevent establishment of woody plants
Temperate Grasslands: Animals
native mammals large: bison, wild horses small burrowers: prairie dogs
Northern Coniferous Forest
aka: taigaDistribution:
broad band across northern North America & Eurasia to edge of arctic tundra
Precipitation: 30 – 70 cm/yr periodic droughts are common
Temperature : winters cold (-50°C in Siberia) summers usually >20°C
Northern Coniferous Forest
aka: taigaDistribution:
broad band across northern North America & Eurasia to edge of arctic tundra
Precipitation: 30 – 70 cm/yr periodic droughts are common
Temperature : winters cold (-50°C in Siberia) summers usually >20°C
Northern Coniferous Forest: Animals
Birds: residents & summer migrantsinsects occasionally kill large tracts of treesMammals:
Moose Brown Bear Siberian Tiger
Temperate Broadleaf Forest
Distribution mainly in midlatitudes of northern
hemisphere smaller areas in Chile, South Africa,
Australia, New Zealand
Temperate Broadleaf Forest
Precipitation: 70 to > 200 cm/yr (includes snow) all seasons have precipitation
Temperature : winter averages ~ 0°C summers hot & humid/ up to 35°C
Temperate Broadleaf Forest: Plants
mature forest has distinct vertical layers including a closed canopy
dominant plants in North America are deciduous trees adaptation: drop leaves as weather gets
colder: uptake of water by roots not feasible when soil frozen
dominant plant in Australia: Eucalyptus
Temperate Broadleaf Forest: Animals
mammals, birds, insects make use of vertical layers
many mammals hibernate in wintermany birds (and some butterflies) migrate
south
Tundra
Distribution: covers arctic: 20% Earth’s land surface tops of high mountains
Precipitation: 20 – 60 cm/yr in arctic tundra >100 cm/yr alpine tundra
Temperature: winter averages < -30°C summer averages < 10°C
Tundra: Plants
mostly herbaceous: mosses, grasses,
forbs + dwarf shrubs & trees, lichens
permafrost (frozen ground year round) prohibits growth of plant roots
Tundra: Animals
Birds: migratory, arriving for nesting in summer
Mammals: Residents: musk ox Migrators: caribou, reindeer
Predators: bears, wolves, foxes