Biomes: Deserts and Grasslands

• Biomes can be classified into deserts, grasslands, temperate deciduous forests, rain forests, taigas, and tundra

Deserts

• Climate region averaging less than 35 cm of annual rainfall
• Most deserts are caused by regions of high atmospheric pressure
• Many different kinds of organisms live in the desert including: cacti, small shrubs, some grasses, scorpions, jackrabbits, snakes, reptiles, birds

Rainshadow deserts

• The location is the eastern side of Cascade Mountain range in Washington state

Fog deserts

• Located between 20-30° latitude, such as the Baja desert of CA & Atacama of South America

High Atmospheric Pressure Deserts

• Located near 30° latitude lines in areas, such as Sahara & Australian deserts
• There are no seasons
• Temperature is not a factor (there are hot deserts and cold deserts)

Grasslands

• Climate regions with too little rainfall to support a forest
• Grasses are main vegetation, and trees are uncommon, with rich soil

Savannas

• Found on every continent except Antarctica and in parts of tropics where there isn’t enough rainfall to create a forest
• Has 2 seasons: rainy & dry
• Animals include large mammals with long legs, small mammals who burrow below ground & birds – all who can avoid fire

Temperate Grasslands

• Grows in middle latitude regions, in interiors of continents, far from large bodies of water
• Has four seasons, with most precipitation in late spring and early summer
• Average annual rainfall 51-89cm
• Summer temperatures can surpass 38°C, while winter temperatures drop below -40°C

Temperate Deciduous Forests

• Climate regions in the mid-latitudes that have 4 seasons
• Location: middle latitude regions between 30°N - 50°N and also 30°S - 50°S
• Average annual rainfall 75-150cm, with 4 distinct seasons
• Winter temperatures can reach -30°C, and summer temperatures can reach up to 30°C
• Has broad-leafed deciduous trees, some pine trees, shrubs, and grasses
• Animals include: deer, bears, coyotes, skunks, beavers, birds, owls, snakes, insects, squirrels, etc.

Rain Forests

• Climate regions found near the equator that have a lot of rainfall & high biodiversity
• Animals located here have extremely high biodiversity
• ½ of all the animal, and plant species of the world are located here
• As much as 100 different species of plants per hectare

Tropical Rain Forests

• Located near the equator, between latitudes of 23.5°N and 23.5°S
• Average annual rainfall of at least 200cm
• Average temperature is 20-25°C all year

Temperate Rain Forests

• Located in the middle-latitude regions (30°N - 50°N and also 30°S - 50°S)
• Approximate annual rainfall of 250cm
• Climate is cool and may be covered in fog

Taigas

• Also known as boreal or coniferous forest
• The largest climate region
• Located in the higher latitudes, between 50°N and 70°N in North America & Eurasia
• Average annual precipitation is 40-100cm, with a short growing season
• Average temperature is below freezing for at least ½ year, with summer temperatures rarely reaching 21°C
• Ground temperature remains at freezing in winter
• Some animals migrate in winter, others hibernate; small mammals burrow underground in winter
• Evergreen trees

Tundra

• A climate region is located in high latitudes

Arctic Tundra

• Found around the Arctic Ocean (high latitude!)
• Coldest biome
• Growing season is only 50-60 days
• Average winter temperature is -34°C, and summer rarely exceeds +12°C
• Permafrost = ground is permanently frozen from 25 to 100cm below the surface
• Has lichens and mosses, reindeer, and polar bears

Alpine Tundra

• Found high in the middle-latitude mountains at high altitude
• Has meadows, grasses, small woody shrubs, chipmunks, and elk

Overview of biomes including deserts and grasslands. Deserts are classified by rainfall and atmospheric pressure. Grasslands have too little rainfall to support a forest.