Biomes and atmospheric circulation

Boreal forest

A cold northern coniferous forest with 4 seasons

Deciduous forest

A mild deciduous forest with 4 seasons

Tundra

Cold, little precipitation, a short growing season and poor nutrients

Grassland

Rolling terrains of grasses, flowers and herbs, with unpredictable precipitation

Tropical rainforest

A very hot and wet rainforest with highest biodiversity

Desert

Very hot and dry with little vegetation and hardly any precipitation

Mediterranean

Flat plains, rocky hills and mountain slopes, very hot and dry with mild winters

Savannah

Dry and hot area composed of mainly grasslands and scattered shrubs and isolated trees

90N atmospheric circulation

• High pressure and cold air sinks

• No condensation occurs, so no rainfall or clouds

• Creates tundra ecosystems (cold and dry)

60N atmospheric circulation

• Low pressure and warm air rises, cold and condenses

• Clouds form and rainfall occurs

• Creates forest ecosystems (mild and wet)

30N atmospheric circulation

• High pressure and cold air sinks

• No condensation occurs, so no rainfall or clouds

• Creates deserts ecosystems (hot and dry)

Equator atmospheric circulation

• Low pressure and warm air rises, cold and condenses

• Clouds form and rainfall occurs

• Creates tropical rainforest ecosystems (hot and wet)

30S atmospheric circulation

• High pressure and cold air sinks

• No condensation occurs, so no rainfall or clouds

• Creates deserts ecosystems (hot and dry)

60S atmospheric circulation

• Low pressure and warm air rises, cold and condenses

• Clouds form and rainfall occurs

• Creates forest ecosystems (mild and wet)

90S atmospheric circulation

• High pressure and cold air sinks

• No condensation occurs so there is no rainfall or clouds

• Creates tundra ecosystems (cold and dry)

How altitude affects ecosystems

100m increase above seal level = ½ C drop in temperature

How mountain ranges affect ecosystems

force moist air from the oceans to ride, cool and condense, forming rainclouds. It rains on the ocean ride of the mountain, and the other side is dry = rain shadow

How ocean currents affect ecosystems

the Gulf stream keeps the UK west coast fairly mild even though the UK is at 50 degrees latitude