4-3 Biomes

Environments are grouped into BIOMES
group of ecosystems that have same climate & dominant communities

10 major world biomes:

TROPICAL RAIN FOREST
has most species
canopy = top
understory = second story below canopy
hot & wet year round; thin, poor soil

TROPICAL DRY FOREST
rainfall is seasonal not year-round
trees are deciduous -lose leaves
warm year round; wet/dry seasons; rich soil

TROPICAL SAVANNA
less rainfall than dry forest, but more than desert
covers of grasses spotted with trees
large animal herds & frequent fires
lions & giraffes

DESERT
dry (less than 25 cm rainfall/year)
extreme temperature changes (hot/cold)
cacti/succulent plants
organisms able to tolerate extreme conditions

TEMPERATE GRASSLAND
plains & prairies; Midwest
very fertile soil
4 seasons - seasonal precipitation, less rain than temperate forest

TEMPERATE WOODLAND & SHRUBLAND
Chaparral= dominated by shrubs
frequent fires
example:Los Angeles, CA

TEMPERATE FOREST
deciduous & coniferous trees (cone-bearing)
rich in humus - decaying leaves
4 seasons - but more rain than grassland

NORTHWESTERN CONIFEROUS FOREST
Abundant rainfall (except summer); lush vegetation
AKA temperate rainforest
Mild temperatures
Pacific NW coast of United States &Canada

BOREAL FOREST (Taiga)
Evergreen forests
Bitterly long winters/ short, mild summers
Moose, black bear, wolves

TUNDRA
permafrost = layer of permanently frozen subsoil
Strong winds -no trees, small plants
mosses, lichens, grasses
arctic fox, caribou

Other land areas include:
Mountain ranges
Polar ice caps

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4-4 Aquatic Ecosystems

Freshwater Ecosystems

A. Flowing-water ecosystem, rivers, streams, creeks, & brooks

B. Standing- water ecosystem, lakes & ponds

Estuary = area where freshwater meets sea

Wetlands = water covers soil

Marine Ecosystem

A. Photic zone - area sunlight reaches

B. Aphotic zone- permanently dark
(See fig. 4-17 p. 109)

*Plankton - microscopic organisms found in water

Other Resources:

Online Exhibit: The World's Biomes
Missouri Botanical Gardens
Blue Planet Biomes
Biomes at NASA Earth Observatory