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Grassland biomes are
large, rolling terrains of grasses, flowers and herbs.
Latitude, soil and local climates for the most part
determine what kinds of plants grow in a particular
grassland. A grassland is a region where the average annual
precipitation is great enough to support grasses, and in
some areas a few trees. The precipitation is so eratic that
drought and fire prevent large forests from growing. Grasses
can survive fires because they grow from the bottom instead
of the top. Their stems can grow again after being burned
off. The soil of most grasslands is also too thin and dry
for trees to survive. When the settlers of
the United States moved westward, they found that the
grasslands, or prairies as they called them, were more than
just dry, flat areas. The prairies contained more than 80
species of animals and 300 species of birds, and hundreds of
species of plants. There are two
different types of grasslands; tall-grass, which are humid
and very wet, and short-grass, which are dry, with hotter
summers and colder winters than the tall-grass prairie. The
settlers found both on their journey west. When they crossed
the Mississippi River they came into some very tall grass,
some as high as 11 feet. Here it rained quite often and it
was very humid. As they traveled further west and approached
the Rocky Mountains, the grass became shorter. There was
less rain in the summer and the winters got colder. These
were the short-grass prairies. Grassland biomes can
be found in the middle latitudes, in the interiors of
continents. They can have either moist continental climates
or dry subtropical climates. In Argentina, South America,
the grasslands are known as pampas. The climate there is
humid and moist. Grasslands in the southern hemisphere tend
to get more precipitation than those in the northern
hemisphere, and the grass tends to be the tall-grass
variety. There is a large
area of grassland that stretch from the Ukraine of Russia
all the way to Siberia. This is a very cold and dry climate
because there is no nearby ocean to get moisture from. Winds
from the arctic aren't blocked by any mountains either.
These are known as the Russian and Asian steppes. In the winter,
grassland temperatures can be as low as -40° F, and in
the summer it can be as high 70° F. There are two real
seasons: a growing season and a dormant season. The growing
season is when there is no frost and plants can grow (which
lasts from 100 to 175 days). During the dormant (not
growing) season nothing can grow because its too cold.
In tropical and
subtropical grasslands the length of the growing season is
determined by how long the rainy season lasts. But in the
temperate grasslands the length of the growing season is
determined by temperature. Plants usually start growing when
the daily temperature reached about 50° F. In temperate
grasslands the average rainfall per year ranges from 10-30
inches. In tropical and sub-tropical grasslands the average
rainfall per year ranges from 25-60 inches per year The
amount of rainfall is very important in determining which
areas are grasslands because it's hard for trees to compete
with grasses in places where the uppers layers of soil are
moist during part of the year but where deeper layer of soil
are always dry. The most common
types of plant life on the North American prairie are
Buffalo Grass, Sunflower, Crazy Weed, Asters, Blazing Stars,
Coneflowers, Goldenrods, Clover, and Wild Indigos.
Some common animals
in the grasslands are Coyotes, Eagles, Bobcats, the Gray
Wolf, Wild Turkey, Fly Catcher, Canadian Geese, Crickets,
Dung Beetle, Bison, and Prairie Chicken. by Sam M.
2000
bibliography: Living In The
Environment: An Introduction To Environmental Science G.
Tyler Miller--20th edition; Wadsworth Publishing, Belmont,
California, Encyclopedia
Britannica, 20th Edition "Temperate
Grasslands" http://www.runet.edu/~swoodwar/CLASSES/GEOG235/biomes/tempgrass/tempgras.html,
(Oct. 2000). "Grasslands",
http://www.ucmp.berkeley.edu/glossary/gloss5/biome/grasslan.html,
(Oct. 2000).
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