Tundra

• The largest biome• Characterized by low rainfall and low

temperatures (Temp -26c to 12c• Shallow soil• Permafrost

– Frozen ground 3 feet or more below the surface.– In winter all the ground if frozen

• Short season 2 month and slow growing• Precipitation=less than 25 cm but most of the

time the water is frozen and there Is little evaporation

Primary producers

• Slow growing and low to the ground.– Going north or up =

• Shrubs = lowest/south• Grasses • lichens = highest/north

Animals

• Large animals where there volume is greater than surface area– Moose– Polar bears– Caribou/reindeer

• Smaller animals– Artic fox

Threats

• Disruption

• Road construction

• Global warming– Decreases in habitat

• Sea rising • Increasing CO2 contribution

Taiga Biome

Characteristics

Characteristics

• Low diversity – Only 20 major species

• Formed from low coniferous cone bearing trees (evergreen)– Pines, Furs and Spruces

• Cold climates and high altitudes -10C to14C• Precipitation= 35-75 cm • Acidic thin soil • minimal under story.• Cold harsh winters with little to no usable water

Animals

• Moose, Voles, Foxes, Deer, Migratory Birds (visiting for the summer), Carnivorous Birds.

Facts

Contain some of the largest wilderness areas world wide.

• Once, during the ice ages formed a continuous band of forest from Europe to Canada (there was a land bridge from Russia to Alaska.

Threats

• Insects– Pine Beatles kill the pines– Spruce bud worm

• Fires– These forests burn every 90 years.

-Limiting forests to no taller than 30 feet

Temperate Deciduous Forests

• Pronounced seasons• Broad leaf plants which lose their leaves.• Warmer winters than taiga Temp =6C to 28C• And wetter precipitation=75-125 cm• Most major cities in the world are in this biome. • Large amounts of fallen leaf matter make thick

nutrient rich soil.• Winters are short and trees may become

dormant for several months.

Organisms

• Less diverse than tropical forests but more diverse than taiga– Deciduous trees and dense underbrush

– Oak, Maple, Ash, Burch, Hemlock,

– Smaller mammals'• Deer, rabbits, squirrels, black bear, migratory

birds.

Threats

• Population growth– Urban Sprawl– Logging……– Introduced species/invasive

Tropical forests

• The highest amounts of diversity: of the 300 thousand plant species world wide 200 thousand may be found in tropical forests.

• 1/5 of the worlds species are contained in tropical rainforests

• Consistent warm temperatures all year. • Temp =20C to34 c and rain fall=200-400cm• Soil is thin and sandy.

– All the nutrients are in the trees. – Many plants Have a beneficial relationship with

nitrobacter forming mycorrhizae

Biota

• Vegetation forms stratified layers called canopies.

• Plants live on the trees=epiphytes

• The tallest are broad leaf bearing trees which do not lose there leaves.

• Animals include kopibarra, sloths

Desert Biome

• Largest range of temperature 7C and 38C• Dry less than 25 cm of rain.• Soil sandy and poor• Plants have adapted to storing water.• Waxy Leaves• Animals burrow/ nocturnal / large surface

areas.• It takes a long time for species to grow.

Deserts

• 2 types – Tropical deserts

• Sahara

– Temperate deserts• The great American desert

• Both have the largest temperature changes of any biome.

• Low diversity

Chaparrel

• Temperature change is seasonal-mild• 30f to 100f• Sunny • High diversity• Rain=10-17 in• Highly flammable in the summer. Burns 25

years• High population density.