Climate and Vegetation

Chapter 5Section 2

Examine the Northern and Western climates of the U.S. and Canada

Objectives:

2/3rds of the Canada and the U.S. State of Alaska lie in higher latitudes and experience older climatesClimate Type?

Most of the continental U.S. and southern 1/3 of Canada lie within temperate climates.Weather?

Hawaii has a tropical climate.

A Varied Region

Large parts of Canada and Alaska lie in a subarctic climate zone.Vegetation?

High Atmospheric pressure areas over the Canadian subarctic spawns the cold winds that chill much of the central U.S. during the winter.

Northern Climates

Lands on the Arctic coastline fall into the tundra climate zone.

Bitter winters and cool summers make it inhospitable for most plants and few people live there.Greenland’s tundra vegetation consists of

sedge, cotton grass, and lichens.Contains few trees, but does have dwarfed

birch, willow, and alder scrubs.

British Columbia- cool and wet.California deserts- dry and sparseRocky Mountains- snow capped.Climate and Vegetation differ widely.

What geographical and natural occurrences create this variation?

Western Climates

The ocean and wind currents combined with the Pacific Ranges give the Pacific Coast from California to southern Alaska a marine west coast climate.

Coniferous forests, ferns, and mosses are common in this region.

Southern California has a Mediterranean climate.

Marine West Coast

The rain shadow effect keeps the plateaus and basins that lie between the Pacific Ranges and the Rocky Mountains hot and dry.

Steppe or desert climates.Important North American deserts: Great Salt

Lake Desert, Death Valley, the Mojave Desert, Chihuahua Desert.

Death Valley- Highest recorded U.S. temperature: 134⁰F

Vegetation: Cacti and hardy windflowers during the brief spring rain.

Plateaus, Basins, and Deserts

The areas adjacent to the deserts experience steppe climates with a mixture of desert scrub, grasslands, or coniferous forests, depending on latitude.

Elevation, not latitude, effects the Rocky Mountains and Pacific Range climates.

Coniferous forest occur below the timberline, but above it, only lichens and mosses exist.

In the late winter and early spring a warm, dry wind called the Chinook may blow down the eastern slopes of the Rockies.

Warming at a rate of 1⁰F for every 180 feet it descends, the Chinook rapidly melts and evaporates the snow at the base of the mountains.

Today I learned…For example…Therefore…Clearly…

Closure:

Examine the Interior, Eastern and Tropical Climates of the U.S. and Canada

Objectives:

The Great Plains, in the center of the continent, have a humid continental climate with bitterly cold winters and hot summers.

The Great Plains benefit from the moist winds that blow north along the Rockies from the Gulf of Mexico and south from the Arctic.

Interior Climates

Prairies, or naturally treeless expanses of grasses, spread across the continent’s midsection.

Each year, rainfall ranges from about 10-30 inches waters prairie grasses, which can grow as much as half an inch a day.

Violent thunderstorms known as super cells spawn tornadoes, twisting funnels of air whose winds can reach 300 mph

Prairies

The tangled prairie roots once formed dense, solidly packed layers of sod, which settlers broke up to plant crops.

When dry weather blanketed the plains in the 1930s, the wind eroded unprotected topsoil, reducing farmlands across several U.S. states to a barren wasteland called the Dust Bowl.Economic hardships, made worse by the Great

Depression, caused mass migrations of people.

The Dust Bowl

Southeast- humid subtropical climate with long muggy summers and mild winters.Deciduous forests extend as far south as

Louisiana, but land has been cleared for farming along the Mississippi River.

Wetlands and swamps, like Florida’s Everglades, shelter a great variety of vegetation and wildlife.

In late summer and early autumn, hurricanes are common.

Eastern Climates

Humid Continental: Extends from the Northeastern U.S. into southeastern Canada.In Canada, a band of deciduous forests and

mixed coniferous forestlands known as 1,375 miles wide sweeps from Newfoundland into the subarctic Yukon Territory.

In the U.S., deciduous forests grow at lower elevations in the South.

In winter, much of Northern American experiences blizzards.

Within the continental U.S., only the extreme top of Florida has a tropical savanna climate.

Hawaii, 2,400 miles west of the mainland, and the Caribbean island of Puerto Rico have tropical rain forests.

Tropical Climate

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Closure:

Page 125 1, 3-6

Class work/ Homework