Transcript Biome
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.