A desert is a region that gets very little rainfall. Where temperatures are high, the rate of evaporation exceeds the rainfall. The ground is dry. Such regions are called hot deserts. But there are also `cold desert’. Although these is a hardly any evaporation in such places, temperatures are so low that the little rain that falls comes in the form of snow. Plants cannot survive in such conditions. Vegetation is thus scarce in both types of deserts and the land cannot be put too much use. Desert is a kind of waste land.
Deserts cover about one –fifth of the total land surface of the world. Some deserts are like great seas of sand while some are rocky or stony deserts.
The Thar Desert is in India, Which is a hot desert because of the lack of rain. There is other hot desert in the world. You will find that the entire hot desert is found between about 15 degree cilices and 30 degree cilices north and south of the equator. These deserts are crossed either by the people of Cancer of the Tropic of Capricorn.
Another feature of the hot deserts is that they are found on the western side of the continents. Why is this? The reason is that the trade winds in this region blow across the land and carry very little moisture. The winds blow from the northeast which means that the eastern part of the continent gets the rain. By the time the winds reach the western part they are very dry. Cold currents too flow towards the equator on the western sides of the continents. Winds that blow across these currents get cooled and lose their moisture. Therefore little rain reaches the land.
Thus land becomes a dry desert. South of the equator the winds blow from the southeast.
The largest hot desert in the world is the Sahara (the Arabic word for desert) which lies south of the Mediterranean Sea and stretches right across North Africa. Smaller hot deserts are found in California in North America, in Arabia and in Central Asia. In the southern Hemisphere we find the Atacama Desert in South Africa and the great Australian desert in Central Australia.
The air in a desert is dry. During the day it is hot, sunny and cloudless. The temperature rises above 30 degree cilices. The nights are starlit, cloudless and cold. The temperature drops to about 10 degree cilices. There is little or on rain, amounting usually to less than 25 cm a year. Hot days and cold nights break up the desert rock by making it expand and contract. Thus most of the deserts are sandy and the strong winds that blow across the deserts carry the grains of sand from one place to another to form sand dunes. Sand dunes grow and often drift in the direction of the world of the wind. Sometimes entire villages have been covered by such drifting dunes.
Just as the northern part of the Thar Desert has become fertile with irrigation, so crops can be grown in all deserts where irrigation is possible.
Most of the Sahara is a plateau about 180 meters high. There are mountains in this desert but about two-thirds of the area is made up shifting sand dunes. Much of this land receives no rain for several years. Suddenly rain comes in one or two fleeting showers. This can cause flash foods, laden with sand and broken desert rock. This can cut deep gorges in the desert, called Wadis in North Africa and canyons in North America. After such storms most of the water runs off into dried up water courses called Wadis. The particles of sand carried by the wind carve the rocks into strange shapes.
Desert plants are well adapted to survive the high temperature and intense heat of hot desert. Most desert plants have thorns or thick, waxy leaves which help to store water and prevent its loss due to evaporation. Their roots may go down deep into the earth to find water, sometimes as deep as 15 meters. Others plants survive the heat and the long periods of drought as seeds or bulbs. These spring to life suddenly when it rains. Palm trees sand gram grows in an oasis.
Villages up in the desert wherever there is a sources of water. Deep down beneath the Sahara are underground rivers. Men are sometimes able to bring this water to the surface by wells and boreholes. Then, that area becomes fertile and is called an Oasis. Water flows through the oasis in irrigation ditches. The size of an oasis can vary. Some oases are thousands of hectares in size; as for example, Kufre and Siwa are two large oases while there are other small ones too.
A permanent settlement usually springs up around an oasis. The people of the oasis usually make their houses out of clay and mud. The roofs are flat and made of palm trunks, covered first with small plants and then plastered with mud. The walls are very thick. This keeps the house cool during the day and warm during the night. The houses are closely packed along wining streets. They have low, small windows so that the people who sit on floors inside the house can see what is happening outside.
The BNS is the most important place in an oasis. It consists of the market place, a mosque, a school and several shops. Each oasis has its own agriculture lands.
There is a high wall around each oasis to keep out the sand that may be carried in by a violent dust storm. These dust storms of the Sahara called Simooms are very dangerous. Fierce winds traveling at a great speed can be quite destructive. In the Saharan and Arabian deserts, mud walls were built around villages for defence against the wandering tribe (nomads) who sometimes attacked the oases. The Tuareg were fierce nomads.
In this type of climate as much land as possible is given to the growing of dates as the date palm flourishes. The long root reaches deep into the soil for moisture and nourishment. The men are kept busy watering managing and pruning the plants or in planting new palms. The palms take four years before they yield a harvest of 6 or 7 huge bunches of golden –brown dates. August is harvest time and consequently a busy time or the oasis –dweller. After dates are harvested, wheat, maize, barely, millet, fruits and vegetables like radishes, onions, tomatoes and peppers are planted in rows between the palms. There are watered by canals or water that is drawn from wells by canals.
The camel has been called `the ship of the desert’, because it was and still is, the most important means of transport as it is specially adapted to travel and work in the desert. Its large, padded feet are splayed to prevent them from sinking in the sand. Its long eyelashes protect their eyes during sandstorms. The nourishment that it needs during long journeys with food is stored in its hump in the form of fat. The camel can also travel for a week without drinking water. Whenever water becomes available, the camel consumes it in large quantities. This water is then stored in the tissues. Besides storing water, the camel can reduce the loss of water by sweating less.
Long ago camels were the main means of transporting dates and salt to the coastal towns here the dates were cleaned and packed for export. In recent years roads have been built between oasis towns and the coastal ports. Now cars fitted with caterpillar wheels can move about without sinking in the sand. Aero plane are also used for longer journeys. These can carry goods far more quickly than camels. Thus oasis towns have become the centre of caravan and motor routes. Some of the men have adopted western clothes and wear a red fez. They have all the comforts of a modern town life.
There is sufficient moisture for coarse grass to grow on the edge of the desert, near the oasis. These form the pasture lands for sheep, goats and camels. The desert people are nomads. Many nomads have flocks of seep and goats as well as camels. They travel with their animals in search of fresh pastures.
They live mainly on sour milk d cottage cheese. Water is carried in goat sin bags. Their tents are usually made of goat’s hair or woven wool on wooden frames so that they can move easily. Their clothes are simple and woven from the hair of their animals. The outer garment is a loose robe that is slit at the sides. It is worn over a pair of baggy pants. The head and shoulders are protected by a cloth which can easily be drawn over the head in case of a storm.
We know about hot dessert and found rainfall in the Sahara is usually below 25 cm per year. As we move southwards towards the Equator, rainfall increase and so there is greater vegetation too. On the edge of the desert the vegetation is poor and scanty consisting of thorny bushes and coarse grass usually. With the increase of rainfall, grass grows more plentiful though only in patches. After the rainy season the grass shoots up higher than a human being. Father south towards the Equator, trees begins to be seen either in a scattered way or as clumps in some place. The trees are umbrella-shaped, exposing only narrow edge to the strong winds.
These areas are called tropical grasslands known as savannas in Africa. Antelopes, giraffes, zebras are to be found here, together with lions, hyenas and jackals prey on them.
It is hot throughout the year. North of the equator, the hot rainy season lasts from May to September and the warm, dry season from October to April. Sometimes during the hot season the temperature rises to 43 degree cilices. During this season the rains make the atmosphere unpleasant and sticky. Later in the year the temperature drops to about 23 degrees cilices. The rainfall for the year is about 70 cm. the savannas of Africa are found in the North and South of the equator.
Vegetation of the savanna
Grass grows well in the savanna. It is short and sparse in the dry region, but grows up to a great height (elephant grass) in the selva (equator forests). Fires are common in the dry seasons and there fore forests are less widespread now.
Some trees and bushes also survive. The trees are often thorny. Some have small leaves top avoid loss of moisture, while others have huge trunks for water storage.
Soils of the savanna
Savanna soils are usually very poor. The soil becomes basked in the dry season and it is used for making bricks. When plants and grass are destroyed by forests fires, soil erosion occurs.
Wild life of the savanna
The African savannas have the largest number of animas in the world. Like the vegetation here, the animals are also specially adapted for survival. The antelope runs or leaps with great speed. The giraffe’s long neck enables it to eat leaves from trees which are too high for other animals. The zebra has stripes to9 enable it o hide in the long grass. The lion and the tiger depend for survival on their speed. The world dogs hunt in packs while the hyenas, jackals and vultures act as scavengers.
People in the savanna
Here it is the environment that decides the activities of people. At first the hunter of animals, humans then became the herder of animals. Wandering from one pasture to another for cattle –grazing, they then settled down and started practicing agriculture and trade. Various tribes have partially cleared the grasslands for cultivation.
Suresh went to visit an uncle of his who owned a coffee estate. To reach this estate he traveled by car on national high way 48. If we travel with Suresh we will soon learn about life on a plantation.
This drive from Chikmagalur to Bababudangiri in Karnataka is very beautiful. Baba Budan was a Muslim saint who was responsible or bringing the coffee seed to India. Today the slopes of the hill that are named after him as well as the surrounding hills are covered with million of coffee bushes.
The house that uncle his uncle lived in was a large imposing bungalow. But life there seemed a bit lonely after the noise and bustle of the city. His cousins too were away at their boarding schools for their education.
Paddy is grown in the district, so rice is available in plenty. The jungle abounds in firewood which is used for looking. So there is little need for cooking gas. The rooms have large, ornate fireplaces. During the monsoon and cold seasons, fires are lit in these to keep out the damp and cold. Vegetables are grown in the backyard. Milk, eggs and honey come from that region too. Shopping is done only once a week as the nearest town is miles away.
There are planters’ clubs as they are known. Though these clubs have Indian members now, they were once exclusively British and even today, the custom of the expatriate Britons survive. Talk of the club now centers mostly on whether there will be another frost in Brazil (the coffee plant cannot stand frost) or another earthquake in Colombia –both of which would give the price of Indian coffee a boost in the world market. Indian produces only two per cent the world’s coffee.
As social life and cultural activities are generally restricted, the planter’s wives are usually thrown to their own resources which means more time in the garden with the livestock and the day-to-day running of the house.
This is the way the planter and his family live, but there are the workers, the pickers and factory workers. They are provided with quarters on the far sides of the plantation. The manager is in change of the general administration of the plantation and it is his duty to see that the workers are provided with proper facilities, which includes winter and rain clothing. There is a crèche where the women leave their babies to be cared for while they go to work. Later they go to schools in the town, or attend the boarding schools if their parents can afford it. There is a health centre attend by a full time nurse on the plantation. The doctor calls everyday to attend on the sick workers. Serious cases of illness are taken by jeep to the hospital in city. A small co-operative society provides the daily needs of the workers and sells the produce of the plantation at cost price. They can go to town for their shopping on their weekly holiday.
The monsoon is an important factor in a plantation for without it the coffee crop would fail. Mid—June brings the monsoon rain drumming steadily on the roof. Plants rot and die while leeches get fat and juicy! Sometimes there are landslides. Clothes never dry, and if they do, they smell and look smoky. The people are confined to their houses during the season.
The coffee plant likes a warm, moist climate and well drained soil and so it grows best on hill-slopes about 900 meters above sea level. Coffee does not grow in north India on account of frost. It only grows in south India, Mainly in Karnataka though Tamil Nadu and Kerala also grows.
Just south of the Arctic circle and stretches in a great continuous belt across Canada, Europe and Asia. We have been dealing with the land of ice and snow. Now as we travel southwards, we find that the temperature is higher and the vegetation changes from moss and lichen to small and scattered trees like the willow and the birch. These trees grow larger as we move southwards until we find dense coniferous forests. The greatest single belt of coniferous forest is the taiga (Russian word for coniferous forests in Siberia.
The bitterly cold winter lasts for a long period of about seven months, and the temperature sometimes drops to as low as 30 degree cilices. The summers are cool and brief, lasting for about three to four months. The highest temperature is about 15 degree cilices in July. During the summer there are long hours of day night- Some times as much as 18 hours. There is just enough heat to melt the snow. Spring and autumn are very brief-about two to four weeks each.
The rainfall is about 200mm in summer and about 25mm during the rest of the year. As the soil is grayish –white in color and not very fertile, only sturdy trees grow here.
As most of the trees here (pines, firs and larches) are cone- shaped, they are called conifers. This shape is very useful as it prevents snow from collecting on the branches and weighting them down. They are evergreen, that is, they do not shed all their leaves (or needles, as they are usually called), at the same time. They have a thick bark so as to protect the trunks from the extreme cold. The food is stored in the trunk. The strong wind just blows through the forests as the needles –shaped leaves do not offer any resistance. These leaves are also small, thick and leathery. This prevents the loss of moisture during the summer months. Remember our climb up Mount Everest? We saw red and white pines, spruce, larch, Douglas firs and balsam firs just like these.
These trees differ from other trees in that the wood is soft and can be easily worked on. This wood is used to make paper, rayon, matches and plywood. So lumbering is an important occupation in North Canada.
As the cutting of trees is known as lumbering, the woodcutter in these parts is known as a lumberjack. These men have to be very tough, as lumbering is a difficult job.
The lumberjacks of Quebec leave their homes as the end of autumn and go to the lumber cams in the middle forest. The lumber camp is made up of number of wooden houses with bunks of sleeping. There is a washroom, with toilet facilities. The officials live in the staff houses some distances away. There is a common dining hall and a kitchen. There is also a store (shop) where the men can buy tobacco, writing paper and some other necessities. The life of a lumberjack is a difficult one. Very early in the morning, they eat a heavy breakfast of porridge, eggs, meat and potatoes, bread and coffee. They carry their own packed lunch. Before sunrise, they set off in horse- drawn sledges.
Group of men which include a head feller are dropped off at different points. The head-feller marks off certain trees and the direction in which they should fall. The lumberjack starts sawing with a trouble-toothed cross cut saw or a motor –powered saw, which, of course, makes the work quicker and easier.
After they have cut about twenty trees, they set about lopping off the branches and cutting the trunks into convenient logs, each about 2.5 meters long, which are then stacked. After he has worked all day, a lumberjack walks back to camp for a hearty dinner and then to early bed.
The logs are taken to the frozen river either by sledges drawn by horses or by a winch to which a cable is attached. They are left there until the spring thaw sets in and the ice melts and carries them downstream to the saw-mills. The larger logs sawn into planks but the smaller ones are ground to pulp for paper.
There is always the danger of a forest fire breaking out and so lumberjacks have to keep a vigilant watch.
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