The distribution & characteristic of ecosystems

What are biomes?

Large-scale ecosystems that spread across continents

They have flora & fauna that are unique to them

What are the 8 major biomes?

Polar regions (Antarctica & Arctic)

Coral reefs

Tropical rainforests

Tropical grasslands

Deserts

Temperate grasslands

Temperate forests

Distribution of polar regions (Antarctica)

→ South pole region

Characteristics of polar regions (Antarctica)

Climate → Covered in snow & ice all year round, 1% of the continent is ice free, spends half the year in darkness, -62°C to -55°C, climate kept within the continent due to circumpolar winds

Flora & fauna → Around 100 species of moss & 300-400 species of lichen grow on exposed rocks, penguins, fur seals, elephant seals, killer whales, lots of phytoplankton

Distribution of polar regions (Arctic)

→ North pole region

→ Greenland

→ Northern parts of Canada & Russia

Characteristics of polar regions (Arctic)

Climate → Covered in snow & ice all year round, spends half the year in darkness, -46°C to -26°C, sea temperature does not fall below -2°C

Flora & fauna → Around 1700 species of plants, no trees due to permafrost, polar bears, wolves, foxes, reindeer, walruses, whales, some animals migrate south during winter, lots of phytoplankton

Distribution of coral reefs

→ Along the Equator, between the Tropic of Cancer & the Tropic of Capricorn

→ In tropical oceans (e.g. Pacific, Indian, Atlantic)

→ Cover less than 1% of the whole ocean

→ 109 countries have coral reefs in their waters

Characteristics of coral reefs

Climate → Warm water temperature, average 18°C, Shallow waters no deeper than 30m to let in sunlight for photosynthesis

Flora & fauna → Sea grasses, coral polyps that feed on plankton & make their own mineral skeleton for calcium carbonate, starfish, crustaceans, sponges

Distribution of tropical rainforests

→ Around the Equator

→ Within the Tropic of Cancer & the Tropic of Capricorn

→ Amazon river basin, South America

→ Southeast Asia

→ Queensland, Australia

Characteristics of tropical rainforests

Climate → Hot & humid, 26°C to 28°C, annual rainfall over 2000mm

Flora & fauna → 15 million species of plants & animals, distinct layers of vegetation (emergent, canopy, under canopy, shrub layer), buttress roots, lianas, monkeys, toucans, chameleons, frogs

Distribution of tropical grasslands

→ Between 5° & 30° north & south of the Equator

→ Most of central Africa, surrounding the Congo basin

→ Northern Australia

→ Brazilian highlands

Characteristics of tropical grasslands

Climate → Long dry season, short wet season, 80% of rainfall occurs in the wet season, rainfall is as low as 10mm in the dry season, around 25°C during daytime

Flora & fauna → Tall & spiky pampas grass, baobab trees with 10m wide trunks to store water, few leaves to reduce transpiration, 40 species of hoofed animals, grazing animals, lions

Distribution of deserts

→ Around 30° north & south of the Equator

→ Sahara in northern Africa

→ Mojave in North America

Characteristics of deserts

Climate → 36°C during daytime, temperatures can fall to -12°C at night due to the lack of insulating cloud cover, annual rainfall around 40mm

Flora & fauna → Most plants are xerophytic, cacti & yucca plants have roots near the surface to absorb water, camels have humps to store water & fat & have long eyelashes to keep sand out, meerkats, snakes

Distribution of temperate grasslands

→ Between 40° & 60° north & south of the Equator

→ Plains of North America

→ Veldts of Africa

→ Steppes of Eurasia

Characteristics of temperate grasslands

Climate → Hot summers (over 38°C), cold winters (low as -40°C), annual rainfall varies from 250mm - 750mm, 75% of rainfall in the summer season

Flora & fauna → Willow & oak trees grow in river valleys, tussock grasses (2m), feather grasses (50cm), borrowing animals, kangaroos, bison, coyotes, wolves, eagles

Distribution of temperate forests

→ Between 40° & 60° north & south of the Equator

→ Eastern North America

→ Western Europe (including the UK)

→ New Zealand

Characteristics of temperate forests

Climate → 4 distinct seasons, warms summers, mild winters, average temperature 10°C, annual rainfall varies from 750mm - 1500mm

Flora & fauna → Deciduous trees shed their leaves in winter, grass & bracken grow on the forest floor, oak trees (30m - 40m), squirrels, owls, pigeons, rabbits, deer, foxes, some animals migrate or harbinate in winter