Natural Vegetation and Wildlife
Forests : Chapter Summary
The plants and trees that grow naturally in a place are called its natural vegetation. The natural vegetation of places differs on the basis of height, its climatic conditions, the slope of land and the thickness of the soil. There are two climatic factors which affect the growth of vegetation largely i.e. temperature and rainfall.
The natural vegetation of the world is classified into four types i.e. Forests, Grasslands, Deserts and Tundra.
Forests are large areas of land covered by trees, plants and underbrush growing in places which receive plenty of rain. The thickness and vegetation of forests changes and forests are further classified in four types i.e. Tropical, Temperate, Mediterranean and Coniferous.
Tropical rainforests lie in the "tropics," between the Tropic of Capricorn and Tropic of Cancer and near the equator. Rainforests receive heavy rainfall throughout the year; the trees here do not shed their leaves completely and appear green throughout the year. Hence, tropical rainforests are also called evergreen forests.
The climate of rainforests is hot and humid. The trees in rainforests form a thick canopy of several layers which is the reason sunlight does not enter the forest even during the day. Hardwood trees like rosewood, ebony and mahogany are commonly found here in addition to bamboos and reeds.
Nearly all types of animals, including microscopic animals, insects and worms, fish, reptiles, amphibians, birds and mammals, are found in the rainforests. The anaconda is one of the world’s largest snakes, can also be found in the tropical rainforest.
The tropical rainforests in India grow on the western slopes of the Western Ghats and the north-eastern regions of Arunachal Pradesh, Meghalaya, Assam and Nagaland, the Terai areas of the Himalayas and the Andaman group of islands.
Tropical deciduous forests or the monsoon forests are those which are green only during the rainy season and shed the leaves in the dry season for conserving water. These forests are not as thick as the rainforests and are found in large parts of India, northern Australia and Central America.
These forests do not receive rain throughout the year and experience seasonal changes. Some examples of trees in Tropical deciduous forests are teak, sal, sandalwood, mahua, khair, wattle, bamboo, semal, sisasm and myrobalan. These trees are used in furniture and construction.
The common animals found here are snails, spiders, snakes, frogs, salamanders, turtles, woodpeckers, hawks, owls, chipmunks, rabbits, weasels, foxes and bears. The soil of monsoon forests is most fertile as it is enriched with dry leaves and dead organisms. As a result, these forests are now being converted into farming lands.
Temperate evergreen forests grow between the mid-latitudinal coastal regions and experience a moderate climate. The rainfall in these forests is intense in the winters while the summers are mild and relatively dry. These are commonly found along the eastern boundaries of the continents like south-east USA, south China and south-east Brazil.
The trees in these forests have broad, flat and leathery leaves which are waxy, to prevent from losing too much water when the air is dry. One can find both hard and soft wood trees like oak, pine, fir and eucalyptus here. The timber from hardwood trees is used for making furniture while the eucalyptus tree gives us eucalyptus oil.
The forests become cool and wet near the middle latitudes around the globe and are called temperate deciduous forests. These are found in the north eastern part of USA, China, New Zealand, Chile and the coastal regions of Western Europe. The trees shed their leaves in autumn and grow again in spring.
Huge trees like oak, ash, maple, beech, chestnut, hickory, elm, basswood and linden, are found here. Most of the food items like walnuts, apples, mushrooms and maple sugar, come from temperate forests. These forests are home for animals like bears, deer, foxes, wolves and weasels and birds like pheasants, monals, bald eagles, red-tailed hawks and turkeys.
The cold woodlands found in the upper areas of North America and Asia, are called as coniferous forests or Taiga or boreal forests. The taiga forests cover about 15% of the earth’s land surface and are the largest land habitat on the earth.
These forests experience long and severe winters and the temperature remains below freezing point for almost 6 months. Tall, cone-bearing softwood evergreen trees like Chir, pine, cedar, needle leaf, coniferous or gymnosperm, fir and spruce are found in these forests. The wood of the coniferous trees is very useful for making pulp, used for manufacturing paper and newsprint. Matchboxes and packing boxes are also made from softwood.
Mosses found here are used as medicines as they possess antibacterial properties and by florists for decoration. The silver fox, mink and polar bear are the common animals here.
Mediterranean forests or Chapparal are mostly found in areas around the Mediterranean sea in Europe, Africa and Asia. They are also found outside the actual Mediterranean region in California in the USA, south west Africa and south western parts of South America and South west Australia.
These regions experience hot dry summers and mild rainy winters. Citrus fruits like figs, olives, oranges and grapes grow well in these regions and hence these are known as the Orchards of the World. Wildlife is not much here but animals like the wild goat, sheep, lynx, wild boar, rabbit and vulture can be found.
Different Types of Forest : Chapter Summary
Forests that grow between the mid-latitudinal coastal regions are called temperate evergreen forests.Temperate evergreen forests experience a moderate climate.
The rainfall in these forests is intense in the cool winter months. The summers are mild and relatively dry. These forests are commonly found along the eastern boundaries of the continents like south-east USA, south China and south-east Brazil. Both hard and soft wood trees like oak, pine, fir and eucalyptus grow here.
As we move towards higher altitudes, near the middle latitudes around the globe, the forests become cool and wet. These forests are called temperate deciduous forests. Temperate deciduous forests are found in the north eastern part of USA, China, New Zealand, Chile and also the coastal regions of Western Europe.
Huge trees, such as oak, ash, maple, beech, chestnut, hickory, elm, basswood and linden, are commonly found here. Animals such as bears, deer, foxes, wolves and weasels are found here. Birds like pheasants, monals, bald eagles, red-tailed hawks and turkeys are also found here.
The cold woodlands found in Northern Asia are called coniferous forests. These are also called Taiga or boreal forests. Taiga covers about 15% of the earth’s land surface and is the largest land habitat on the earth. These forests experience long and severe spells of winters. The summers are very short.
Tall, cone-bearing softwood evergreen trees like Chir, pine, cedar, needle leaf, coniferous or gymnosperm, fir and spruce are some of the important varieties of trees found in these forests. The regions with tall, thick shrubs are called Mediterranean forests or Chapparal.
They are also found outside the actual Mediterranean region in California in the USA, south west Africa and south western parts of South America and South west Australia. These regions experience hot dry summers and mild rainy winters.
Grassland, Desert and Tundra : Chapter Summary
Grasslands are vast open areas covered by grass and are classified into two types—tropical grasslands and temperate grasslands. Tropical grasslands are located near the equator, between the Tropic of
Cancer and the Tropic of Capricorn and are found in Australia, India, Africa and South America. The climate Tropical grasslands is usually hot and dry throughout the year and the rainfall can vary from heavy to moderate, followed by long bouts of drought. The grass in tropical grasslands can grow up to a height of 3-4 metres.
Large animals like elephants, giraffes, lions, leopards, hyenas, zebras, buffaloes and kangaroos along with small animals like mice, moles, gophers, ground squirrels, snakes, worms, termites, and beetles are found here. Birds like ostrich, emu and rhea and different varieties of snakes are found too. Some examples of tropical grasslands are the Savannahs in Africa, the Campos in Brazil and the Llanos in Venezuela.
The temperate grasslands are covered by short and nutritious varieties of grasses and are located to the north of the Tropic of Cancer and to the south of the Tropic of Capricorn. These grasslands receive very little rainfall and experience hot summers and cold winters.
The major temperate grasslands are the Velds of South Africa, the Prairies of North America, the Pampas of Argentina, the Steppes of Central Asia, and the Downs of Australia.
Large animals like bison, pronghorn, deer, wolves, coyotes and zebras and small animals like prairie dogs, rabbits and mice live here. Birds like grouses, meadowlarks, quails, sparrows, hawks and owls, and snakes and insects are also found in temperate grasslands.
The soil of temperate grasslands is very fertile and hence these are major farm lands for growing cereal crops such as wheat, oats, barley, milo and corn.
Tropical deserts are the driest and hottest places on earth where the rainfall is very scanty and irregular. Owing to these conditions, vegetation and wildlife is scarce. Animals like camel and mongoose, and a variety of reptiles and insects live in these deserts. Cactus, prickly pears, turpentine bush and yuccas commonly grow here.
The Sahara Desert of Africa is the world’s largest tropical desert and stretches for 32,50,000 square miles. In India, the Thar desert in Rajasthan is another example of tropical desert. Tundra regions are lands which are extremely cold, covered with frosts and devoid of trees. Deserts in the polar regions of Antarctica, Greenland and parts of North America are examples of Tundra regions.
There are two types of tundra regions in the world i.e. Arctic Tundra and Alpine Tundra. The arctic tundra is mainly located around the North Pole while the alpine tundra can be found in the mountainous regions.
The vegetation in these regions is sparse and treeless limited to mosses, lichens and very small shrubs. Seals, walruses, musk-oxen, arctic owls, polar bears and snow foxes are form of wildlife found here. These animals have a thick fur and skin which protects them from the acute cold.