Hey everyone, it's Kelsey. Generally speaking, temperatures warm up the closer you are to the
equator and cool down the closer you are to the poles. But it's not always that simple.
As we learned before, climate often depends as much on altitude or proximity to water
as it does on latitude, which makes for a vast, varied, and complex spectrum
of climate regions across the world. Today we continue our study of the two largest countries
in North America - Canada and the United States - and because the terrain in these countries
is just as vast, varied, and complex as their climates, we can expect to find within their
borders an impressive array of ecosystems, too. Join me as we explore the climates and
ecosystems of these unique regions and some of the people, plants, and animals living there.
If you look at any climate map of Canada, you'll see the vast majority of its land mass broken
into two main climate regions - the tundra and the subarctic, with some maps adding a polar climate
region in the very far north. What do these designations mean? Well, as we learned before,
tundra refers to a vast, flat, treeless region in which the subsoil is permanently frozen.
Tundra occupies approximately 550,000 square miles across a number of Canadian provinces including
the Yukon, the Northwest Territories, Nunavut, and parts of Manitoba, Ontario, Quebec, and Labrador.
The subarctic, bordering the tundra to the south and stretching from the American state of Alaska
all the way across Canada to the eastern tip of Newfoundland, is a climate region
characterized by long cold winters, short cool summers, and relatively little precipitation.
The Canadian subarctic includes almost 2 million square miles of forest and is home to a variety
of indigenous First Nations people, many of whom were traditionally organized into bands or
groups who spoke the same language dialect and were related by kinship and common traditions.
People of the eastern subarctic belong to the Algonquian language family, for example,
while people of the western subarctic belong to the Athapascan, or Dene, language family. Both
the Dene and the Algonquian people traditionally subsisted by hunting, fishing, and gathering.
The most prevalent ecosystems found within the subarctic and tundra climate regions
are coniferous forest, mixed forest, and not surprisingly, the tundra ecosystem. A coniferous
forest is composed of cone-bearing, needle-leaved, or scale-leaved evergreen trees - that is,
trees that retain their green leaves year-round. A mixed forest contains both coniferous trees
and deciduous trees, which are trees that shed their leaves seasonally. The tundra ecosystem,
often referred to as the tundra biome, is the coldest on earth and least inhabited by humans.
Very little grows in the tundra and the plants that do have adapted to protect themselves
from snow and wind damage and to store nutrients for the long, harsh winter months.
Although plant diversity is relatively low, the tundra manages to support a
surprising array of fascinating land and sea creatures, including the orca, whale, narwhal,
polar bear, walrus, arctic wolf, arctic fox, caribou, ermine, and lemming. Canada's tundra
and subarctic forest ecosystems are typically called boreal forests, while America's highland
coniferous forests - those in the Rockies, for example - are called temperate forests.
Some of the major climate regions shared by both the United States and Canada
are the marine west coast, the highlands, the semi-arid, and the humid continental.
All of these regions at some point straddle the 5,525-mile U.S.-Canada border.
The marine west coast climate region, stretching from the southeast corner of
Alaska along the Canadian coast down to the southwest corner of Oregon,
is characterized by steady temperatures and ample rainfall all year long. Vancouver and
Seattle - both well known for rain - are two major cities within the marine west
coast climate region. Coniferous forest is the dominant ecosystem here. The Hoh rainforest,
located on the Olympic Peninsula in the state of Washington, is one of America's largest
rainforests and is home to the spotted owl, the cougar, the black-tailed deer, and, yes,
the banana slug, beloved mascot of the University of California at Santa Cruz. Go Slugs!
The highlands climate region, where rapid elevation changes
cause rapid climatic changes over short distances, is found in high mountain areas
and is typically colder and wetter than lowland areas. The Rockies, the Cascades,
and the Sierra Nevada are all mountain ranges in the highland climate region, the dominant
ecosystems of which are the coniferous forest and the helpfully named highland ecosystem.
Some of the animals found in highland ecosystems of the western United States are the wolverine,
bighorn sheep, mountain goat, moose, elk, mule, deer, black bear, grizzly bear, and gray wolf.
The semi-arid climate region, a sort of transitional zone between drier and wetter areas,
includes wide swaths of sagebrush typical of the Great Basin, which lies between the Rockies
and the Sierra Nevada in the American west. The dominant ecosystems here are the desert scrub,
home to the chipmunk, jackrabbit, and kangaroo rat, and the temperate grassland of the
Great Plains, home to the black-footed ferret, pronghorn, bison, and coyote.
The humid continental climate region exists between polar and tropical air masses and is
marked by hot summers and cold winters. New England, southern Ontario, Quebec,
and much of the American Midwest are located in the humid continental climate region.
Humid is a bit of a misleading name for this region.
It's not necessarily humid. It just has enough precipitation not to be considered arid or
semi-arid. And almost all areas within this region experience snow at some point during
the year. The prevailing ecosystem here is the mid-latitude deciduous forest,
also known as the temperate deciduous forest, home to hardwoods like maple, oak, birch,
and magnolia and animals like the white-tailed deer, raccoon, opossum, and porcupine.
The southern half of the United States enjoys four more major climate regions not typically
seen in Canada - the Mediterranean, the arid, the humid subtropical, and the tropical wet and dry.
The mild Mediterranean climate region, affected by changes in ocean current and water temperatures,
is characterized by hot dry summers and cool wet winters and really has only
two seasons - summer and winter - and rarely, if ever, experiences snowfall.
Much of California is located in the Mediterranean climate region, which is why it's not unusual to
see Californians wearing shorts and flip-flops on the beach while people in Chicago are still
bundled up in heavy parkas. The prevailing ecosystem here is chaparral, where you'll
find road runners, scrub jays, woodpeckers, and on rare occasions, mountain lions or coyotes.
The arid climate region is characterized by a severe lack of water. America's deserts,
notably the Mojave, are located mostly within this zone. The predominant ecosystem here is
the desert scrub, mentioned earlier, where you'll see plants like the Joshua tree and
the creosote bush eking out a living under harsh conditions. The humid subtropical climate region,
noted for relatively high temperatures and evenly distributed rainfall throughout the year,
makes up the majority of the southeastern United States. The southern tip of Florida falls within
the tropical wet and dry climate region, which is marked by distinct wet and dry seasons,
with most of the rain coming during the high-sun summer months.
Its dominant ecosystems are tropical forest and subtropical forest that include huge swaths of
wetlands, most notably the Everglades, home to the alligator, egret, and Florida panther.
As we move forward in our study of the United States and Canada,
keep in mind the climates and the ecosystems of these countries - as well as the physical
characteristics we explored earlier - because these are the factors that ultimately determine
who and what can survive there and the methods by which they adapt and thrive. In other words,
terrain, climate, and ecosystem are fundamental considerations behind culture, movement,
and interaction. And a full understanding of all these factors together is what makes
the geographical study of a place exciting and worthwhile. Until next time... keep exploring!