Grassland
Grassland biomes are unaltered areas
of land where grass in the dominant plant life, as opposed to other terrestrial
biomes where trees occupy most of the land surface. Grassland are found around
the globe and have served as grazing areas for a large number of animals, and
have been exploited as farming grounds or plantations by humans. They occupy
about one quarter of the Earth’s land area. Grasslands are considered the
transitional biome and are found between deserts and forests.
They have been divided into follows
two parts:
Savannah
Savannah is grassland with scattered
individual trees. They cover almost half the surface of Africa and large areas
of Australia, South America, and India, Climate is the most important factor in
creating a Savannah. These are always found in warm or hot climate where the
annual rainfall is from about 40 to 80 cm per year, Savannah has both a dry and
a rainy season. The soil of the savannah is porous, with rapid drainage of
water. It has only a thin layer of humus, which provides vegetation with
nutrients. The predominant vegetation consists of grasses and forbs (small
broad-leaved plants that grow with grasses). Different savannas support
different grasses due to disparities in rainfall and soil conditions. Seasonal
fires Play a vital role in the savannah’s biodiversity. The world’s greatest
diversity of ungulates (hoofed mammals) is found on the savannas of Africa and
hence they are also called The big game country.
Characteristic Features
The savannah stays pretty warm all
year, it cools down some during the dry season, but stays warm and humid during
the rainy season.
Savannas have two distinct seasons
in, regards to precipitation. There is a rainy season in the summer with around
40 cm to 80cm of rainfall and a dry season in the winter when less than 10 cm
of rain may fall.
The majority of the savannah is
covered in different types of grasses including lemon grass, Rhodes grass, star
grass, and Bermuda grass.
There are also lots of tress scattered
about the savannah. Some of these trees include the acacia tree, the baobab
tree, and the jackal Berry tree.
The plants need to be able to survive
the dry season and drought in the savannah. Some store water and energy in
their roots, bulbs, or trunks, others have roots that go deep into the ground
to reach the low water table.
Fires are an important part of the
savannah, During the dry season fires clear out old dead grass and make way for
new growth. Most of the plants will survive because they have extensive root
systems that allow them to grow back quickly after a fire. The trees have thick
bark which helps them to survive. The animals generally can run to escape the
fire. Some animals burrow deep into the ground to survive. Insects generally die
by the millions in a fire, but this provides a feast to many birds and animals.
There are many herbivores in the
savannah biome which also bring many carnivores. Herbivores have developed
traits which help them escape predators such as being fast, being large, or
being tall.
Although there are various types of
soil in the savannah biome, it is not suitable for farming.
Temperate Grassland
Temperate grasslands are
characterized as having grasses as the dominant Vegetation. Trees and large
scrubs are absent, Temperature very more from summer to from winter, and the
amount of rainfall is less in temperate grasslands than in Savannas. The major
manifestations are the steppes of the former Soviet Union, the Pustas of
Hungary, the pampas of Argentina and Uruguay, Veldts of South Africa, and the
prairies of Central North America. The soil of the temperate grasslands is deep
and dark, with fertile environment as determined by temperature, rainfall, and
soil conditions. Today, People use steppes to graze livestock and to go grow
wheat and other crops.
Characteristics Features
Due to their location in interiors of
continents, the annual range of temperature is huge ranging from -2 C to 20.C
respectively in the winter and summer
Rainfall is generally less in
temperate grasslands than in tropical savannah, falling, usually in temperature
in temperate grasslands in the late spring and early summer, there is an
average of 50-80cm of rainfall a year,
Unlike savannahs that can have trees
and shrubs scattered throughout, temperate grasslands have trees and shrubs
absent.
Grasses of this area have adapted to
cold temperatures, drought, and occasional fires.
These grasses have deep, massive root
systems that take hold in the soil. This allows the grasses to remain firmly
rooted in the ground to reduce erosion and to conserve waiter.
The following are the major regional
expressions of grasslands recognized around the globe.
Veldts of South Africa
Pustaz of Hungary
Pampas of Argentina/Uruguay
Steppes of Russia/China
Plains and Prairies of North America
The dominant vertebrates in
grasslands are herbivorous or plant-eating grazers called ungulates. Ungulates
are mammals with hoofs, like horses and deer. Their long legs help them run
fast to escape grassland predators. The temperate grassland does not have much
animal diversity, especially compared to the Savannah. Some animals that
inhabit temperate grasslands in North America are bison, antelope, birds,
gophers, prairie dogs, coyotes, and insects.
Temperate grassland soil has fertile
upper layers, created from fires and the decay of deep grass roots, which makes
it ideal for farming and gazing.
DESERT
Deserts cover about one fifth of our
planet, and are caused by extremely low rainfall over an areal. Theses biomes
are nonetheless home for many plants and animals which have through the course
of their evolution adapted to this dry environment. Although most deserts, such
as the Sahara of North Africa and the deserts of the South-Western U.S.,
Mexico, and Australia, occur at low latitudes, another kind of desert, cold
deserts, occur in the basin and range area of Utah and Nevada and in parts of
western Asia. Most deserts have a considerable amount of specialized
vegetation, as well as specialized Vertebrate and invertebrate animals, Soils
often have little or no organic matter, Disturbances are common in the form of
occasional fires or cold weather, and sudden, infrequent, but intense rains
that cause flooding. There are relatively few large mammals in deserts because
most are not capable of storing sufficient water and withstanding the heat.
Deserts often provide little shelter from the sun for large animals. The
dominant animals of warm deserts are non-mammalian vertebrates, Such as
reptiles.
Desert biomes can be classified
according to several characteristics. There are four major types of deserts:
Hot and Arid Desert
These generally occur at low latitudes,
and can be found in Sahara, South western North-America, South-America,
Australia, and middle east. Seasons in the arid desert are generally dry and
hot, with few occurrences of rain during the winter. The heat peaks to extremes
during the daytime because there are no clouds to shield the earth from the
sun’s rays. When it does rain, it is not uncommon for the rain to evaporate
before hitting the ground. The soil is usually either sand or coarse, and
rocky, Vegetation consists mainly of shrubs and small trees of which the leaves
have evolved to retain water, Most desert life forms have followed this train
of evolution, with animal species being mostly active at night (nocturnal)
Characteristic Features
Temperature exhibit daily extremes
because the atmosphere contains little humidity to block the sun’s rays. Desert
surfaces receive a little more than twice the solar radiation received by humid
regions and lose almost twice as much heat at night. Many mean annual
temperatures range from 20-25° C. The extreme maximum ranges from 43.5-49° C.
Minimum temperatures Sometimes drop to - 18°C.
Rainfall is usually very low and/or
concentrated in short bursts between long rainless periods. Evaporation rates
regularly exceed rainfall rates. Sometimes rain starts falling and evaporates
before reaching the ground. Rainfall is lowest on the Atacama Desert of Chile,
where it averages less than 1.5cm.
Oases are vegetated areas moistened
by springs, wells, or by irrigation. Many are artificial. Oases are often only
places in deserts that support crops and permanent habitation.
Canopy in most deserts is very rare.
Plants are mainly ground-hugging shrubs and short woody trees.
Leaves are “replete” (fully supported
with nutrients) with water-conserving characteristics. They tend to be small,
thick and covered with a thick cuticle (outer layer)
In the cacti, the leaves are
much-reduced (to spines) and photosynthetic activity is restricted to the
stems. Some plants open their stomata (microscopic openings in the Grasses of
this area have adapted to cold temperatures, drought, and occasional fires.
These grasses have deep, Massive root
systems that take hold in the soil. This allows the, grasses to remain firmly
rooted in the ground to reduce erosion and to conserve waiter.
The following are the major regional
expressions of grasslands recognized around the globe.
Veldts of South Africa
Pustaz of Hungary
Pampas of Argentina/Uruguay
Steppes of Russia/China
Plains and Prairies of North America
The dominant vertebrates in grasslands
are herbivorous or plant-eating grazers called ungulates. Ungulates are mammals
with hoofs, like horses and deer. Their long legs help them run fast to escape
grassland predators, The temperate grassland does not have much animal
diversity, especially compared to the Savannah. Some animals that inhabit.
Temperate grasslands in North America are bison, antelope, birds, gophers,
prairie dogs, coyotes, and insects.
Temperate grassland soil has fertile
upper layers, created from fires and the decay of deep grass roots, which makes
it deal for farming and grazing.
Cold Desert
Deserts cover about one fifth of our
Planet, and are caused by extremely low rainfall over an area. Theses biomes
are nonetheless home for many plants and animals which have through the course
of their evolution adapted to this dry environment. Although most deserts,
Australia, occur at low latitudes, another kind of desert, cold deserts , occur
in the basin and range area of Utah and Nevada and in parts of western Asia.
Most deserts have a considerable amount of specialized vegetation, as well as
specialized vertebrate and invertebrate animals. Soils often have abundant
nutrients because they need only water to the form of occasional fires or cold
weather, and sudden, infrequent, but intense rains that cause flooding. There
are relatively few large mammals in deserts often provide little shelter from
the sun for large animals. The dominant animals of warm deserts are
non-mammalian vertebrates, such as reptiles.
Characteristic Features
These deserts are characterized by
cold winters with snowfall and high overall rainfall throughout the winter and
occasionally over the summer.
They have short, moist, and
moderately warm summers with fairly long, cold winters, The mean winter
temperature is between -2 to 4° C and the mean summer temperature is between
21-26° C.
The winters receive quite a bit of
snow. The mean annual precipitation ranges from 15-26 cm. Annual precipitation
has reached a maximum of 46 cm and a minimum of 9 cm.
The plants are widely scattered. In
areas of shad scale, about 10 percent of the ground is covered, but in some
areas of sage brush, it approaches 85 percent. Plant heights very between 15 cm
and 122 cm. The main plants are deciduous, most having spiny leaves.
Widely distributed animals are jack
rabbits, Kangaroo rats, Kangaroo mice, pocket mice, grasshopper mice, and
antelope ground squirrels. All except the jack rabbits are burrowers. The
burrowing habit also applies to carnivores like the badger, kit fox, and
coyote, Several lizards do some burrowing and moving of soil. Deer are found only
in the winter.
The soil is heavy, Silty, and salty,
It contains alluvial fans where soil is relatively porous and drainage is good
so that most of the salt has been leached out.
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