In zones where the rainfall is insufficient
for the development of forests, the temperate grassland arise,
that are characterized by the presence of herbaceous vegetation.
In North America this biome extends from the Missisipi river
to the east and the Great Lakes to the northeast to Rocky
mountains in the west. The region of grassland of South America
is well-known like pampa. It includes the south of Brazil,
Uruguay and center-east of Argentina; all this region of natural
grass is operated for agriculture and livestock farming and
numerous industries have settled down there.
The aggravating factor of grasslands is water.
The annual average of precipitations is about 20-35 inches,
and the annual average temperature is 100°F.
In the most humid zones, where rains balance
with the evaporation from the naked ground and the sweating
of the plants, the high grass abounds. As the precipitations
diminish, the grass is lower and the prairie ends up becoming
steppe and semi-desert. The plants adapt to the climate, so
that some grow in the warm station and others in autumn and
spring.
The ground of the prairie is characterized
to have abundant undercoat, horizon 0, constituted by
organic matter in decomposition. In the second layer,
also of great thickness, this matter is mixed with ground
particles. In the great development of these two layers
is the fertility of the prairies.
GEOGRAPHIC
DISTRIBUTION OF THE PRAIRIES
A space for agriculture
Throughout the water course there are shrubs and trees.
The natural grass has been replaced by the culture of
cereals and pastures apt for the livestock farming.
The fertility of the ground of the prairies is remarkable.
The grass that grow there has very short periods of
life, reason why humus, that forms from organic matter
in decomposition and minerals of the ground, is accumulated
in a heavy layer.
The fires that happen in these regions devastate the
shrubs, but not them underground stems of the grass.
These return to appear, fertilized in addition by the
carbonization to the organic matter thanks to the action
of the fire.
The grassland is a biome where the influence of the
man can be observed with clarity. In Argentina, the
most humid regions are operated for farming of l wheat,
maize, oats, barley and rye, and driest it has dedicated
to the livestock farming, ovine and first of all bovine.
But not always that task took control of the necessary
care from the ecological point of view. When not being
respected the technique of rotation of farming, many
regions have been eroded and degraded.
The animals of the grassland
Of the prairies of South America are original
rodents and other small animals: vizcachas, maras and cuises,
armadillos like the mulitas ones, weasels, small lizards and
foxes. Between the birds are ñandúes, owls,
ducks, martinetas, chajáes, teros, and chimangos .
Of the species of birds that populate the hoisted sites distinguish
horneros, cardinals, calandrias, benteveos, tijeretas, churrinches
and hummingbird.
In South America are in danger of extinction
puma and the deer of Pampas. In North America the bisons,
that until the last century formed great flocks, now live
in natural reserves. On the other hand, also are animals characteristic
of those prairies the American badger, the lined firedamp
and coyote. In the Asian prairies is the antelope saiga, that
also frequents steppes.
The fauna of the prairie plays a fundamental
role in the preservation of the natural balance for the food
web. Numerous excavating animal species of the prairies, when
removing the ground, modify the mineral content of this one
and make possible the growth of vegetal species. Under earth
the earthworms and other invertebrates, oxygenate the ground,
along with million bacteria that disturb the organic remainders.
