Download Introduction to Biomes!

Life on Land – The Organism’s
Environment
Chapter 2
Introduction to Biomes!
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What are biomes?
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Major divisions of the terrestrial (land)
environment
 Distinguished by the type of plant life
found
How/Why do biomes form?
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It’s the climate!!!!
Large-Scale Patterns of Climatic Variation
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Spherical shape and tilt of earth’s axis cause
uneven heating of earth’s surface.
This leads to predictable patterns based on
latitude!
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Solar-Driven Air Circulation
Tropical rain forests @
equator
Deserts @ 300
Temperate forests @ 600
Rain forests
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Temperature, Atmospheric
Circulation, and Precipitation
Coriolis effect causes deflection of winds
clockwise in the N hemisphere and
counterclockwise in the S hemisphere.
Trade winds between equator & 300
Westerlies between 300 & 600
Easterlies above and below 600
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The Coriolis Effect – More detail
Deflection due
to Earth’s
rotation – also
effects ocean
currents!
 http://
www.youtube.com/watch?v
=_36MiCUS1ro
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Soil : Foundation of Terrestrial Biomes
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Soil is a complex mixture of living and nonliving material.
 Classification based on vertical layering
(soil horizons). O, A, B, C
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Terrestrial Biomes – More detail
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Biomes
 Distinguished by the type of plant life
found
 Plant life corresponds to climate
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Biome #1 - Tropical Rainforests
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Warm and wet! Huge diversity of organisms!
 Rainfall of 2000-4000 mm, 25-27 0C
Most occur within 10o latitude of equator.
Low seasonality
Infertile soils
Has food and medicine for human populations increasingly exploited.
http://
www.youtube.com/watch?v
=3xN7bPTz7gw
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Biome #2 - Tropical Dry Forest
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Usually located between 10o - 25o latitude.
Climate more seasonal than tropical rainforest.
Soils generally richer in nutrients, but vulnerable
Shares many animal and plant species with
tropical rainforests.
As threatened as tropical rain forest
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Biome #3 - Tropical Savanna
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Most occur north and south of tropical dry forests
within 10o - 20o of the equator.
Climate alternates between wet / dry seasons.
 Drought associated with dry season leads to
lightning-caused wildfires – keeps grasses
dominant
Soils have low water permeability.
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Biome #4 - Desert
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Major bands at 30o N and 30o S latitude.
Dry (hot or cold)
Soil usually extremely low in organic
matter.
Plant cover ranges from sparse to absent.
Animal abundance low, but biodiversity
may behttp://www.youtube.com/watch?v=
high.
 Strong
drlTYQESyUg
behavioral adaptations.
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Biome #5 - Mediterranean Woodland and
Shrubland (called chaparral in California)
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Occur in all continents except Antarctica.
Climate cool and moist in fall, winter, and spring,
but can be hot and dry in summer.
Trees and shrubs typically evergreen (always
leaves).
Fire-resistant plants
Low to moderate soil fertility
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Biome # 6 - Temperate Grassland
Extremely widespread distribution.
Largest biome in North America
Hot and cold seasons
Experience periodic droughts.
Soils tend extremely nutrient rich and deep.
Thoroughly dominated by herbaceous vegetation –
fire important to keep grasses dominant.
Largely converted to agriculture
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Biome #7 - Temperate Forest (Old Growth)
Majority lie between 40o and 50o latitude.
Fertile soils
 Long growing seasons dominated by deciduous
plants.
Biomass production can be very high.
Many major human population centers.
Redwood forests in California
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Biome #8 - Boreal Forest (Taiga)
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Confined to Northern Hemisphere.
 Covers 11% of earth’s land area.
Infertile soils
Long, severe winters. Permafrost
Huge temperature ranges!
Relatively high animal density.
Historically, low levels of human intrusion.
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Biome # 9 - Tundra
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Covers most of lands north of Arctic Circle.
Cold. Low precipitation
Soggy summers
Permafrost
Human intrusion historically low
Low vegetation; many animals
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Biome #10 - Mountains: Islands in the Sky
Built by geological processes
Temperature, precipitation and soils change with
elevation and latitude.
Flora and fauna change with elevation.
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Pop Quiz!!!
http://earthobservatory.nasa.gov/Experim
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