Contents
Biology Topics encompass the study of both prokaryotic and eukaryotic organisms.
What is Red Data Book and Reforestration ? Explain
The species which no longer exist anywhere on the earth are called extinct species. Extinct species are those which have died out completely. A species becomes extinct when the last living member of that species dies. The extinct species may be of animals or plants.
For example, a type of animal which no longer exists on earth is called an extinct animal. It means that this animal has no living member on the earth. All the members of this animal species have died out. For example, the animals called ‘dinosaurs’ which lived on this earth in ancient times have become extinct a long time ago (see Figure).
Some of the examples of extinct species of animals are : Dinosaur, Dodo, Cave lion, Caspian tiger, and Irish deer. All the members of these animals are dead. We can never see these animals again. They have all vanished from this earth for various reasons.
The species which are facing the risk of extinction are called endangered species. Endangered species are animals and plants which are on the verge of vanishing from the earth. They are the animals and plants that exist in small numbers on the earth, and if we do not take quick action to save them, they may be lost for ever (or become extinct).
For example, the wild animals whose numbers are diminishing to such a low level that they might face extinction soon, are known as endangered animals. An animal species becomes endangered either because it is few in numbers or it is being killed by predators or it is being hunted by human beings or its natural habitat is being destroyed by deforestation (leading to lack of shelter, food and water).
In fact, the survival of some wild animals is becoming more and more difficult day by day because of the destruction of their natural habitats. Some examples of endangered animal species are : Tiger, Snow leopard, Great Indian rhinoceros, Asiatic lion, Desert cat, Lion-tailed macaque, Naindapha flying squirrel, and Kashmir stag (see Figure).
It is not only the big animals which face extinction. The small animals are much more in danger of becoming extinct than the bigger animals. At times, people kill snakes, frogs, lizards, bats and owls without realising their importance in the ecosystem.
They might be small in size but their role in the ecosystem is very important which cannot be ignored. The small animals form parts of food chains and food webs which are essential for maintaining a balance in nature. By killing the small animals, we are actually harming ourselves. This point will become more clear from the following example of snake.
Snake is a spiall, wild animal. The skin of snakes is in great demand for making fancy leather goods, so the snake skin sells at a high price in the market. Now, to make some easy money, some greedy people kill the snakes indiscriminately in large numbers to obtain their skin.
This large scale killing of snakes disrupts the food chains in which snakes occur and creates an imbalance in nature. For example, snake is a friend of the farmer in the sense that it eats vermins like rats and mice which are pests and damage the crops (see Figure).
Now, when the snakes are killed in large numbers to obtain their skin, the population of snakes is reduced greatly. Due to lesser number of predator’ snakes, the population of pests like rats and mice in crop-fields increases. The increased number of rats and mice in the fields damage the standing crops leading to loss in the production of foodgrains. We will now discuss the red data book.
Red Data Book
Red Data Book is the ‘book’ (or publication) which keeps a record of all the endangered animals, plants and other species. Actually, Red Data Book contains a list of species which are in danger of becoming extinct. There are different Red Data Books for plants, animals and other species.
Red Data Books are being published in many different countries and provide useful information on the threat status of the various species. There is also a Red Data Book of India. Some of the endangered species of animals listed in the Red Data Book of India are : Flying squirrel, Indian giant squirrel, Barasingha, Black buck, Himalayan musk deer, Great Indian rhinoceros, Snow leopard, and Tiger.
The advantage of maintaining Red Data Book is that we come to know which species of animals, plants, etc., are very small in number and facing the danger of extinction so that timely remedial steps can be taken by the Authorities concerned to prevent their extinction.
Migration
The process of a bird (or other animal) moving from one place to another according to the season, is called migration. In other words, when a bird (or other animal) moves from one place to another in one season and returns in a different season, it is called migration. Migration of birds (or other animals) is an adaptation to escape the harsh and cold conditions of their normal habitat in winter so as to survive. Let us discuss the migration of birds.
When the winter sets in cold regions of the earth, the climate becomes extremely cold in those regions. The birds, which normally live in these regions, migrate (fly off) to far flung warmer places on earth to escape the extremely cold winter climate and survive (see Figure).
And when the winter season is over, these birds fly back to their original habitats in the cold regions. The birds which move from very cold regions to warmer regions in winter, and go back after the winter is over are called migratory birds. Migratory birds fly to far away places every year during a particular time because of climatic changes. The purpose of migration of birds is to survive by escaping the extremely cold conditions of their natural habitat and also for breeding (by laying eggs).
India is one of the destinations of many of the migratory birds coming from the very cold regions of the earth. One of the most common migratory bird which comes to India every year for a few months is the Siberian crane. The normal habitat of Siberian crane is Siberia (which is a very cold place).
When winter sets in Siberia and it gets extremely cold, the Siberian crane flies thousands of kilometres and comes to warmer places in India such as Bharatpur in Rajasthan, Sultanpur in Haryana, some wet lands of North-East, and some other parts of India.
The Siberian cranes stay in the warmer places in India for a few months. The Siberian cranes fly back to Siberia when the winter ends there and climate becomes favourable. We will now discuss the recycling of paper.
Recycling of Paper
Paper is one of the important products we get from the forests. Paper is made from wood pulp that is produced from the wood of forest trees. It has been estimated that 17 full grown trees are needed to make 1 tonne of paper. So, many trees have to be cut down from the forests to make paper.
Paper making is another cause of deforestation. So, we should save paper to save the forest trees. If each one of us saves just one sheet of paper in a day, we can save many trees in a year. We can save paper by writing fully on both sides of every sheet of paper in our notebook (without leaving any blank sheets).
We can also save paper by using chalk and slate for doing rough work (instead of paper notebook). Reuse of paper means that, if possible, we should use the ‘used paper’ again. For example, the ‘used paper envelopes’ can be reversed inside out and used again.
The term ‘recycling of paper’ means to process the waste paper (to make new paper) so that it can be used again. Paper can be recycled from old newspapers, magazines, books, notebooks, and packaging materials after removing ink from them.
If all of us keep on collecting old newspapers, magazines, books, notebooks and paper wrappers, etc., and send them to paper mills for recycling through a junk dealer (kabadiwala), we will be able to save many forest trees from being cut down. In fact, paper can be recycled five to seven times for use.
We should ‘save paper’, ‘reuse paper’ and ‘recycle paper’. By doing this, we will not only save trees but also save energy and water needed for manufacturing paper. The amount of harmful chemicals used in paper making will also be reduced.
From the above discussion we conclude that we should save paper, reuse paper and recycle paper :
- to save forest trees from being cut down,
- to save water used in paper making,
- to save energy (electricity) used in making paper, and
- to reduce the amount of harmful chemicals used in paper making.
Reforestation
The answer to the problem of deforestation is reforestation. The planting of trees in an area in which forests were destroyed, is called reforestation (see Figure).
The term ‘reforestation’ means ‘to cover again with forest’ (by planting new trees). The planted trees should generally be of the same species which were cut down from the forest during deforestation. We should plant at least as many trees as have been cut down.
In this way, the forests will continue to have sufficient number of trees all the time. Forests are called green wealth of a country. We have already caused tremendous damage to our lush green forests by deforestation. If we have to retain our ‘green wealth’ for future generations, then planting of more trees (reforestation) is the only option.
Reforestation can also take place naturally. If the deforested area is left undisturbed for some time, it re-establishes itself by the natural growth of trees. This is called natural reforestation. There is no role of human beings in natural reforestation.
Advantages of Reforestation
Reforestation has several advantages. Some of the advantages of reforestation are given below :
- Reforestation produces a large quantity of raw materials for industry (like paper industry), timber trade, etc.
- Reforestation will lead to a decrease in global warming by reducing the amount of carbon dioxide gas in the atmosphere.
- Reforestation increases rainfall in an area. This will raise groundwater level and prevent droughts.
- Reforestation prevents soil erosion and floods.
- Reforestation increases the area of earth under forests which is good for the conservation of wildlife.
In order to meet the ever-increasing demand for wood in factories and for shelter (building houses, furniture, etc.), forest trees are being cut continuously. It is quite justified to cut a limited number of trees for genuine developmental purposes. But at the same time, an equal number of new trees should be planted (in place of cut down trees) to maintain a balance in nature and avoid unpleasant consequences of deforestation.
There is a Forest Conservation Act in India. The Forest Conservation Act is aimed at the preservation and conservation of natural forests and at the same time meeting the basic needs of the people living in or near the forests.