BiomesBiomes4.34.3

BiomesBiomes

• What is a biome? • A complex of terrestrial communities that cover a large area characterized by certain soil and climate conditions and particular plants and animals.

BiomesBiomes• Can all kinds of

organisms live in every biome?

• What allows species to survive in their biome?

• No- Not all species of organisms can live in every biome.

• Species have adaptations to help them adapt to different conditions

ToleranceTolerance

• What is meant by tolerance?

• Ability to survive and reproduce under conditions that differ from their optimal conditions.

• Too much or too little of any environmental factor can make it difficult for an organism to survive.

Frozen wood frog

http://www.pbs.org/wgbh/nova/sciencenow/video/3209/i05.html

Biomes & ClimateBiomes & Climate• What are the

two main components of climate?

• What is a microclimate?

• Temperature • Precipitation

• A small area within a biome where the climate differs from the climate around– When driving to school on a

sunny day, you go through a valley blanketed by fog

The 10 Major BiomesThe 10 Major Biomes

• Tropical rain forest

• Tropical dry forest

• Tropical savanna

• Desert

• Temperate grassland

• Temperate woodland & scrubland

• Temperate forest• Northwestern

coniferous forest• Boreal forest

(Taiga)• Tundra

The Major BiomesThe Major Biomes• What can cause

variations within a biome?

• What is a transitional area?

• Microclimates • Differences in exposure • Elevation above or below sea

level• Presence of rock outcroppings

• Areas between one biome and the next where plants and animals become more or less common to the biomes adjacent one another

Tropical Rain ForestTropical Rain Forest• Canopy

– 50-80 m above the forest floor

• Understory – area below the canopy

• Abiotic – hot & wet year-

round– thin, nutrient poor

soils

• Biotic – home to more

species than all other biomes combined

• Geographic distribution– South & Central America– Southeast Asia– Parts of Africa– Southern India– NE Australia

Tropical Dry ForestTropical Dry Forest

• Rainfall is highly seasonal.

• Trees drop their leaves during dry season.

• Abiotic– warm year-round– alternating wet & dry

seasons– rich soils subject to

erosion

• Geographic Distrib.– Parts of Africa– South & Central America– Mexico– India– Australia– Tropical Islands

• Biotic– deciduous trees, drought-

tolerant plants – tigers, monkeys,

elephants, birds, snakes, monitor lizards, etc.

Tropical SavannaTropical Savanna• More seasonal

rainfall than deserts, but less than tropical dry forests

• Abiotic – warm temperatures– seasonal rainfall– compact soil– frequent lightning fires

• Geographic Dist.– Eastern Africa– Southern Brazil– Northern

Australia

• Biotic – Grasslands. – Spotted with isolated trees

and small groves– lions, cheetahs,

rhinoceroses, elephants, giraffes, baboons, eagles, ostrich, etc.

DesertDesert

• Annual precipitation is less than 25 cm. Vary based on elevation and latitude. Extreme temperature changes & extreme conditions

• Abiotic – Low precipitation

– variable temps

– soils rich in minerals but poor in organic material

• Geographic Dist.– Africa– Asia– Middle East– United States– Mexico– South America – Australia

• Biotic – Mountain lions,

bobcats, pronghorn antelope, bighorn sheep,

– owls, hawks, rattlesnakes, lizards, etc.

Temperate Temperate GrasslandsGrasslands• Rich mix of

grasses and some of the world’s most fertile soil.

• Abiotic – Warm to hot summers, cold

winters – moderate seasonal precipitation – fertile soils– occasional fires

• Geographic Dist.– Central Asia– North America– Australia– Central Europe– South America upland

plateaus

• Biotic

– Lush perennial grasses, most drought, fire, & cold resistant

– coyotes, wolves, grizzly bears

– Rabbits, prairie dogs, snakes, etc.

Temperate Woodland & Temperate Woodland & ScrublandScrubland

• Semiarid climate. Growth of dense low plants that contain flammable oils makes fires a constant threat.

• Abiotic– Hot, dry summers– Cool, moist winters– Thin, nutrient-poor

soils– Periodic fires

• Geographic Dist.– Western coast of North

& South America– Areas around the

Mediterranean Sea– South Africa– Australia

• Biotic– Woody evergreen

shrubs, oily herbs– Coyotes, fox, bobcats– Deer, rabbits, squirrels– Lizards, snakes,

butterflies, etc.

Temperate ForestTemperate Forest

• Cold winters that halt plant growth for several months. Deciduous trees shed leaves in autumn, new plant growth in spring.

• Abiotic– Cold to moderate

winters– Warm summers– Year-round precipitation– Fertile soils

• Geographic Dist.– Eastern US– SE Canada– Most of Europe– Parts of Japan– China– Australia

• Biotic– Coniferous trees &

deciduous trees, mosses, ferns

– Deer, black bear, squirrels, skunk

– Songbirds, turkeys

Northwestern Coniferous Northwestern Coniferous Forest (Temperate Rain Forest (Temperate Rain Forest)Forest)• Mild, moist air from

Pacific Ocean provides abundant rainfall.

• Abiotic– Mild temperatures– Abundant precipitation during

fall, winter, & spring– Relatively cool, dry summer– Rocky, acidic soils

• Geographic Dist.– Pacific coast of NW US– Canada– Northern California to

Alaska

• Biotic– Redwood trees, Spruce– Bears, elk, deer, owls, bobcats,

weasels, etc.Twilight Series is set here

Boreal Forest (Tiaga)Boreal Forest (Tiaga)

• Also referred to as Taiga. Bitterly cold winters, mild summers to allow ground to thaw.

• Abiotic– Long, cold winters– Short, mild summers– Moderate precipitation– High humidity– Acidic, nutrient-poor

soils

• Geographic Dist.– North America– Asia– Northern Europe

• Biotic– Needleleaf coniferous

trees, small berry-bearing shrubs

– Lynxes, timber wolves, moose, beaver, songbirds, migratory birds

TundraTundra• Characterized by

permafrost (layer of permanently frozen subsoil). Ground thaws a few centimeters in summer becoming soggy & wet.

• Abiotic– Strong winds– Low precipitation– Short, soggy summers– Long, cold, dark winters– Poorly developed soils

• Geographic Dist.– Northern North America– Asia– Europe

• Biotic– Ground hugging plants– Musk ox, arctic fox,

caribou, lemmings, small rodents, migratory waterfowl, shore birds

Other Land AreasOther Land Areas

• Some areas of land on Earth do not neatly fall into the major biome categories.

• Mountain Ranges- found on all continents. – Abiotic and biotic

conditions vary with elevation. As elevation rises, temperature decreases and precipitation increases.

Other Land Areas• Polar Ice Caps-

border the tundra, cold all year

• Northern polar regions- – Arctic Ocean covered with sea

ice & a thick ice cap over most of Greenland

• South polar regions-– Antarctica is covered by a layer

of ice nearly 5 km thick– Dominant wildlife:

• Penguins and marine mammals