Watch this video to learn about the four main types of vegetation found in America.
REGIONS CAN BE DEFINED AND MAPPED IN MANY WAYS
USING DIFFERENT CRITERIA.
CLIMATIC REGIONS RANGE FROM TROPICAL TO POLAR,
BUT MOST PARTS OF THE UNITED STATES AND CANADA
ARE IN THE MIDLATITUDES OF THE NORTHERN HEMISPHERE
AND HAVE MIDLATITUDE CLIMATES.
MIDLATITUDE CLIMATES HAVE A DISTINCT CHANGE OF SEASONS.
WINTERS ARE MILD IN THE SOUTH
AND BECOME INCREASINGLY LONGER AND COLDER TOWARD THE NORTH.
VEGETATION REGIONS ARE SIMILAR TO CLIMATIC REGIONS,
BECAUSE NATURAL VEGETATION VARIES
WITH TEMPERATURE AND PRECIPITATION.
THE NATURAL VEGETATION REGIONS OF THE UNITED STATES AND CANADA
CAN BE GROUPED INTO FOUR BROAD CATEGORIES.
FORESTS ARE FOUND WHERE THERE IS ENOUGH MOISTURE
FOR TREE GROWTH.
GRASSLANDS ARE COMMON IN DRIER REGIONS.
DESERT VEGETATION WITH BARREN GROUND BETWEEN PLANTS
IS FOUND IN AREAS THAT HAVE VERY LITTLE PRECIPITATION.
TUNDRA, A TYPE OF LOW VEGETATION,
IS FOUND AT HIGHER ELEVATIONS IN THE MOUNTAINS
AND ABOVE THE TREE LINE IN ARCTIC REGIONS.
EACH OF THESE VEGETATION REGIONS PROVIDES HABITAT
FOR DIFFERENT TYPES OF WILD ANIMALS.
MOST OF NORTH AMERICA'S NATURAL VEGETATION
HAS BEEN REPLACED BY PASTURES, AGRICULTURAL CROPLANDS,
AND URBAN DEVELOPMENT.
MUCH OF THE NATURAL VEGETATION AND THE WILDLIFE
THAT WE CAN SEE TODAY
HAS BEEN PRESERVED IN NATIONAL PARKS.
LANDFORMS INCLUDE NEARLY LEVEL PLAINS,
ROLLING HILLS, CANYON-CUT PLATEAUS,
AND HIGH MOUNTAINS.
PLAINS ARE USUALLY LOW IN ELEVATION
AND HAVE LOW RELIEF.
ELEVATION IS THE HEIGHT OF A LAND SURFACE ABOVE SEA LEVEL,
AND RELIEF IS THE DISTANCE BETWEEN
THE HIGHEST AND LOWEST POINTS IN THE LANDSCAPE.
A LANDSCAPE WITH LOW RELIEF IS VERY FLAT TO GENTLY ROLLING
LIKE YOU CAN SEE HERE IN THE MISSISSIPPI VALLEY.
A LANDSCAPE WITH HIGH RELIEF,
SUCH AS THIS MOUNTAIN LANDSCAPE IN MONTANA,
HAS A LOT OF VERTICAL DISTANCE
BETWEEN ITS HIGHEST AND LOWEST POINTS.
PLATEAU SURFACES MAY BE AS FLAT AS PLAINS,
BUT PLATEAUS ARE USUALLY HIGHER IN ELEVATION THAN PLAINS.
IN SOME PLACES,
DEEP CANYONS MAY BE CUT INTO A PLATEAU'S SURFACE.
HILLS HAVE A MODERATE RELIEF WITH A DISTINCT DIFFERENCE
BETWEEN THE ELEVATION OF VALLEYS AND SUMMITS.
MOUNTAIN LANDSCAPES HAVE HIGH RELIEF,
AND THE MOUNTAINSIDE AND PEAKS ARE OFTEN JAGGED
WITH EXPOSED ROCK FACES.
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Transcript
Wildlife, or animals, also live in different areas depending on the weather and where their food source is located. North America is home to a variety of different animals. Meet some of them in this video.
IN THE COLD ARCTIC TUNDRA, THE LYNX ROAMS THE LAND
WITH PAWS THAT ARE BIG AND A FACE THAT IS GRAND.
WITH FUR THAT IS THICK, LYNX MANAGE THE COLD.
THE FUR KEEPS THEM WARM -- AT LEAST THAT'S WHAT WE'RE TOLD.
LOOK IN A STREAM AND YOU MAY FIND AN OTTER.
DO YOU HAVE ANY DOUBT THESE CRITTERS LOVE WATER?
COOL MOUNTAIN WATER IS WHAT THEY LIKE BEST.
THEY FISH AND THEY HUNT, AND SOMETIMES THEY REST.
IN THE MOUNTAIN FORESTS IS A PLACE YOU'LL FIND DEER
WITH THE PLENTIFUL BRUSH THAT ATTRACTS THE DEER HERE.
DEER ARE CALLED BROWSERS,
WHICH MEANS THAT THEY EAT BRUSH, LEAVES, AND TWIGS,
BUT THEY NEVER EAT MEAT.
GRAZERS, LIKE BISON, THEY LOVE GRASSY LAND,
WHERE THEY STAND AND THEY EAT,
AND THEY EAT AND THEY STAND.
WITH VERY FEW TREES, GRASSY PLAINS ARE IDEAL
FOR STAMPEDING BISON IN SEARCH OF A MEAL.
WHO COULD FORGET THE SWAMPS OF THE SOUTH,
WHERE THE ALLIGATOR LIVES WITH ITS LARGE, FEARSOME MOUTH?
THESE COLD-BLOODED REPTILES LOVE WHERE IT'S WARM.
WHEN THEY SWIM IN THE WATER, THEY STRIKE QUITE A FORM.
IN LUSH RAIN FORESTS, IGUANAS CLIMB TREES.
THEY CLIMB UP THE BRANCHES AND EAT LOTS OF LEAVES.
THEIR COLOR BLENDS WELL WITH THIS GREEN, LEAFY PLACE,
BUT WHY WOULD THEY HIDE SUCH A FANTASTIC FACE?
Transcript
