Forests: Our Lifeline PDF

12 Forests: Our Lifeline O ne evening Boojho entered the “This is because the forests serve as park with an elderly person. He green lungs and water purifying systems introduced him to his friends. in nature”, Prof Ahmad ex...

12 Forests: Our Lifeline O ne evening Boojho entered the “This is because the forests serve as park with an elderly person. He green lungs and water purifying systems introduced him to his friends. in nature”, Prof Ahmad explained. The Prof Ahmad was a scientist working in children were confused. Prof Ahmad the university. The children started realised that the children had not visited playing while Prof Ahmad sat on a a forest. The children also wanted to bench in the corner. He was tired as he know more about the forest, so they had participated in the golden jubilee decided to visit it with Prof Ahmad. celebrations of the town. After a while, 12.1 VISIT TO A FOREST the children also came and sat around One Sunday morning, the children him. They wanted to know about the packed a few things like a knife, a hand celebrations. Prof Ahmad told them that lens, a stick, a notebook and walked after the cultural programme, the together through a forest trail near a senior people discussed the town’s village. On their way, they met Tibu, a unemployment problem. A plan was young boy of their age group, of nearby proposed to put up a factory by clearing village, who was taking cattle for grazing an area of the forest just outside the along with his aunt. He was very agile, town. This would give the increasing running here and there to keep the herd population of the town a chance to get together. When he saw the children, jobs. The children were very surprised Tibu also started walking along with when Prof Ahmad told them that many them, while his aunt went on a different people had objected to this idea. path. As soon as they entered the forest Tibu raised his hand and signalled them to keep quiet because noise could disturb the animals living in the forest. Tibu then took them to a place at a height to show them the broad view of the forest. Children were surprised because they could not see any land (Fig. 12.1). The different treetops had formed green cover over the land. However, the cover was not uniformly green. The Fig. 12.1 A view of a forest 142 SCIENCE Reprint 2024-25 environment was peaceful and a cool breeze was blowing. This made children quite fresh and happy. While coming down, they got excited on hearing a sudden sound of birds and some noise from the top branches of the trees. Tibu told them to relax since it was a normal phenomenon here. Because of the children’s presence, some monkeys had climbed higher up on the trees where they disturbed the birds. Animals often give this type of warning call to alert other animals. Tibu also told that many other animals like boar, bison, jackals, porcupine, elephants live in the deeper areas of the forest Fig. 12.3 Forest as habitat (Fig. 12.2). Prof Ahmad cautioned children that they should not go deep an example of a habitat in Class VI into the forest. (Fig. 12.3). They could see now how the Boojho and Paheli remembered that forest provides a home for many animals they have studied about forests as and plants. Fig. 12.2 Some forest animals FORESTS: OUR LIFELINE 143 Reprint 2024-25  Neem Sheesham Semal Fig. 12.4 Some forest plants covered with different types of creepers and climbers. The sun was barely visible through the leaves of the trees, making it quite dark inside the forest. Activity 12.1 Bambooo Observe the various things in your home and make a list of those which are made The land where the children were from material which may have been walking was uneven and covered with obtained from the forest. many trees. Tibu helped them to identify You might have many wooden items sal, teak, semal, sheesham, neem, on your list like plywood, fuel wood, palash, fig, khair, amla, bamboo, boxes, paper, matchsticks, and kachnar (Fig. 12.4). Prof Ahmad pointed furniture. Do you know that gum, oils, out that there are several other trees, spices, fodder for animals and medicinal shrubs, herbs and grasses in the forest. plants are also some of the products The forest floor and the trees were also which we get from the forest (Fig. 12.5). 144 SCIENCE Reprint 2024-25  Based on the products that we get Prof Ahmad asked children to look from plants, try to fill Table 12.1. One up and observe how the branches of the example of each plant is already given. tall trees look like a roof over the other Fill the table by adding more examples. plants in the forest. He told them that Sheila wondered who would have this is called a canopy (Fig. 12.7). planted these trees. Prof Ahmad replied Activity 12.2 that in nature trees produce enough seeds. The forest floor provides Visit a forest or a park in your favourable conditions for them to neighbourhood. Observe the trees and germinate and develop into seedlings try to identify them. You can take the help of some elders or books on trees. List the characteristics of the trees that Honey you observe, such as the height, shape of leaves, crown, flowers, and fruits. Also draw the crowns of some trees. Prof Ahmad pointed out that trees Sealing wax Wooden statue had crowns of different types and sizes. These had created different horizontal layers in the forest. These are known as understoreys (Fig. 12.7). Giant and tall trees constituted the top layer followed Catechu by shrubs and tall grasses, and herbs formed the lowest layer. Gum Fig. 12.5 Forest products and saplings. Some grow up into trees. He added that branchy part of a tree above the stem is known as the crown of the tree (Fig. 12.6). Fig. 12.6 Some crown shapes Table 12.1 Plants and their products Gum Timber Medicinal Oil Babool Sheesham Neem Sandalwood FORESTS: OUR LIFELINE 145 Reprint 2024-25  Canopy Understorey Fig. 12.7 Canopy and under storeys in a forest “Would we see similar kind of trees They had a close look at the bushes. in every forest?” — asked Boojho. While doing that their hair and clothes Prof Ahmad said, “No, due to different had seeds and thorns clinging to them. climatic conditions there are variations They came across numerous insects, in the types of trees and other plants. spiders, squirrels, ants and various The types of animals also differ from other small animals on the bark of the forest to forest.” trees, plant leaves and on decaying A few children were busy watching leaves on the forest floor (Fig. 12.8). They beautiful butterflies fluttering here and started making sketches of these there on the flowers of shrubs and herbs. creatures. The forest floor seemed dark coloured and was covered with a layer of dead and decaying leaves, fruits, seeds, twigs and small herbs. The decaying matter was moist and warm. Children picked up various seeds and leaves for their collection. Walking over the dead leaf layer on the forest floor was like walking over a spongy carpet! Is the decaying matter always warm? Prof Ahmad suggested that the children could perform an activity to get an Fig. 12.8 Forest floor answer to this question. 146 SCIENCE Reprint 2024-25 Activity 12.3 depend ultimately on plants for food. Organisms which feed on plants often Dig a small pit. Put vegetable waste and get eaten by other organisms, and so leaves in it. Cover them with soil. Add on. For example, grass is eaten by some water. After three days, remove the insects, which in turn, is taken by the upper layer of the soil. Does the pit feel frog. The frog is consumed by snakes. warm inside? This is said to form a food chain: Paheli asked, “There are so many Grass insects frog snake eagle. trees here. Also, there are many forest Many food chains can be found in the like this. What difference will it make if forest. All food chains are linked. If any we cut some trees for a factory?” one food chain is disturbed, it affects Prof Ahmad said, “You have read other food chains. Every part of the about autotrophs, heterotrophs and forest is dependent on the other parts. saprotrophs. You have learnt how green If we remove one component, say trees, plants produce food. All animals, all other components would be affected.” whether herbivores or carnivores, Oxygen Carbon dioxide Photosynthesis Decomposers Soil Water Nutrients Fig. 12.9 Interrelationship of plant, soil and decomposers in a forest FORESTS: OUR LIFELINE 147 Reprint 2024-25  Prof Ahmad asked children to pick Paheli reminded Prof Ahmad that he up leaves from the forest floor and had not explained why forests are called observe them under a hand lens. They green lungs. Prof Ahmad explained that found tiny mushrooms over the plants release oxygen through the decaying leaves. They also saw an army process of photosynthesis. The plants of tiny insects, millipedes, ants and help to provide oxygen for animal beetle on them. They were wondering respiration. They also maintain the how these organisms live there. Prof Ahmad explained that apart from these animals which are easily seen, there are several Paheli reminded their organisms and micro-organisms that friends that they have live in the soil. Paheli wondered what studied photosynthesis in mushroom and other micro-organisms Chapter 1. eat. Prof Ahmad replied that they feed upon the dead plant and animal tissues and convert them into a dark coloured substance called humus. In which layer of the soil would you find humus? What is its importance to the soil? The micro-organisms which convert the dead plants and animals to humus are known as decomposers. These Fig. 12.10 Balance of oxygen and carbon micro-organisms play an important role dioxide in the forest. Soon, Paheli removed some dead leaves and discovered under them balance of oxygen and carbon dioxide a layer of humus on forest floor. The in the atmosphere (Fig. 12.10). That is presence of humus ensures that the why forests are called lungs. nutrients of the dead plants and The children saw clouds forming in animals are released into the soil. From the sky. Boojho recalled what he had there, these nutrients are again absorbed learnt about the water cycle in Class VI. by the roots of the living plants. “What Trees take in water from their roots and happens if an animal dies in the forest?” release water vapour into the air Sheila asked. Tibu replied the dead through evaporation. animals become food for vultures, crows, If there were fewer trees, how will the jackals and insects.” In this way, the water cycle be affected? nutrients are cycled. So, nothing goes Tibu told them that the forest is not waste in a forest (Fig. 12.9). just home to plants and animals. Many people also live in the forest. Some of 148 SCIENCE Reprint 2024-25 them may belong to different tribes. Tibu showed the children droppings of some explained that these people depend animals, and explained the difference mostly on the forests. The forest provides between various types of droppings. them with food, shelter, water and Prof Ahmad informed them that the medicines. They have traditional forest officers could recognise the knowledge about many medicinal plants presence of some animals in the forest in the forest. by their droppings and footprints. While Boojho was drinking water Boojho called every one and showed from a small stream, he saw some deer them a large, decaying heap of animal crossing the stream (Fig. 12.11). They dropping. Several beetles and grubs disappeared into the bushes. The dense were feeding on the heap and a bunch bushes and the tall grass provide of seedlings was sprouting. “These animals with the food and shelter. They seedlings are of the herbs and shrubs. Fig. 12.11 Deer in a forest Fig. 12.12 A sapling on a wall The animals also disperse the seeds of certain plants and help the forest to grow Paheli remembered that she and regenerate. The decaying animal saw a Pipal sapling on the dung also provides nutrients to the sidewall in her school. Can you seedlings to grow”, said Prof Ahmad. help her to understand how this After listening to this, Boojho noted would have happened? in his notebook, “By harbouring greater variety of plants, the forest provides also protect them from carnivores that greater opportunities for food and live in the forest. habitat for the herbivores. Larger Tibu then started looking closely at number of herbivores means increased the forest floor. Soon he called and availability of food for a variety of FORESTS: OUR LIFELINE 149 Reprint 2024-25  Rain Transpiration and evaporation The closed canopy and many layers of vegetation slow down the speed of raindrops Covered ground with decaying material acts Root system like a sponge The root system helps water to seep down in the ground Water table Fig. 12.13 Rainwater drips from the trees and seeps into the ground carnivores. The wide variety of animals suggested another route for going back. helps the forest to regenerate and grow. While they were going back, it started Decomposers help in maintaining the raining. However, surprisingly, they saw supply of nutrients to the growing plants that the raindrops were not hitting the in the forest. Therefore, the forest is a forest floor directly. The uppermost layer ‘dynamic living entity’ — full of life and of the forest canopy intercepted the flow vitality.” of raindrops, and most of the water was It was about afternoon and the coming down through the branches and children wanted to go back. Tibu the stems of the trees. From the leaves it 150 SCIENCE Reprint 2024-25 was dripping slowly over branches of the that area were created after clearing the shrubs and herbs (Fig. 12.13). They forest about sixty years ago. Tibu’s found that the ground was still dry. After grandfather told them that when he was about half an hour, the rain stopped. young, the village was not as large as it They noticed that the layer of dead was now. It was also surrounded leaves over the forest floor appeared wet by forests. Construction of roads, now. But water did not stagnate in the buildings, industrial development and forest. increasing demand of wood created Boojho thought that if it had rained pressure on the forests and it started so heavily in his town, it would have vanishing. He was not happy that the flooded the drains and roads. forest adjoining their village is not What would happen if it rains heavily regenerating and is on the verge of in your town? disappearing due to overgrazing of Prof Ahmad told them that the forest animals and indiscriminate felling of also acts as a natural absorber of trees. Prof Ahmad said that if we did rainwater and allows it to seep. It helps things wisely we could preserve forests maintain the water table throughout the and environment as well as have year. Forests not only help in controlling development. floods but also help maintain the flow Children prepared a few pictures to of water in the streams so that we get a show the consequences of such an steady supply of water. On the other event. hand, if trees are not present, rain hits At the end of the visit, Prof Ahmad the ground directly and may flood the asked children to sum up the area around it. Heavy rain may also importance of forests. The children damages the soil. Roots of trees normally wrote: Forests provide us with oxygen. bind the soil together, but in their They protect soil and provide habitat to absence the soil is washed away or a large number of animals. Forests eroded. help in bringing good rainfall in The children spent an hour at Tibu’s neighbouring areas. They are a source village on their way back. The weather of medicinal plants, timber and many of the village was quite pleasant. Villagers other useful products. We must preserve told them that due to the surrounding our forests. forest, they receive good rainfall. The air also remained cool. Noise pollution, too is less because the forest absorbs the noise of the nearby highway. What would happen if The children learnt about the history forests disappear? of the village. It surprised them that the villages and the agricultural fields of FORESTS: OUR LIFELINE 151 Reprint 2024-25  1 2 1 If forests disappear, the amount of carbon dioxide in air will increase, resulting in the increase of earth’s temperature. 2 In the absence of trees and plants, the animals will not get food and shelter. 3 In the absence of trees, the soil will not hold water, which will cause floods. 4 Deforestation will endanger our life and environment. Think, what we can do to preserve our forests. 3 4 152 SCIENCE Reprint 2024-25  Keywords Canopy Deforestation Seed dispersal Crown Humus Soil erosion Decomposers Regeneration Understorey What you have learnt We get various products from the forests surrounding us. Forest is a system comprising various plants, animals and micro-organisms. In a forest, trees form the uppermost layer, followed by shrubs. The herbs form the lowest layer of vegetation. Different layers of vegetation provide food and shelter for animals, birds and insects. The various components of the forest are interdependent on one another. The forest keeps on growing and changing, and can regenerate. In the forest, there is interaction between soil, water, air and living organisms. Forests protect the soil from erosion. Soil helps forests to grow and regenerate. Forests are the lifeline for the forest-dwelling communities. Forests influence climate, water cycle and air quality. Exercises 1. Explain how animals dwelling in the forest help it grow and regenerate. 2. Explain how forests prevent floods. 3. What are decomposers? Name any two of them. What do they do in the forest? 4. Explain the role of forest in maintaining the balance between oxygen and carbon dioxide in the atmosphere. 5. Explain why there is no waste in a forest. 6. List five products we get from forests? FORESTS: OUR LIFELINE 153 Reprint 2024-25  7. Fill in the blanks: (a) The insects, butterflies, honeybees and birds help flowering plants in. (b) A forest is a purifier of and. (c) Herbs form the layer in the forest. (d) The decaying leaves and animal droppings in a forest enrich the. 8. Why should we worry about the conditions and issues related to forests far from us? 9. Explain why there is a need of variety of animals and plants in a forest. 10. In Fig. 12.15, the artist has forgotten to put the labels and directions on the arrows. Mark the directions on the arrows and label the diagram using the following labels: clouds, rain, atmosphere, carbon dioxide, oxygen, plants, animals, soil, roots, water table. 11. Which of the following is not a forest product? (i) Gum (ii) Plywood (iii) Sealing wax Carbon dioxide (iv) Kerosene 12. Which of the following statements is not correct? Oxygen (i) Forests protect the soil from erosion. (ii) Plants and animals in a forest are not depedent on one another. (iii) Forests influence the climate and water cycle. (iv) Soil helps forests to grow and regenerate. Fig. 12.15 154 SCIENCE Reprint 2024-25  13. Micro-organisms act upon the dead plants to produce (i) sand (ii) mushrooms (iii) humus (iv) wood Extended Learning — Activities and Projects 1. The Department of Environment is to decide whether some portion of a forest in your area could be cleared for a housing complex. Write a letter to the department explaining your point of view as a concerned citizen. 2. Visit a forest. Here is a list of points that would make your visit more fruitful. (a) Make sure that you have permission to go into the forest. (b) Make sure that you can find your way around. Get a map and go along with some one who is familiar with the area. (c) Keep a record of the things you see and do. Observations make the visit interesting. Sketches and photographs are useful. (d) You may record bird calls. (e) Collect different kinds of seeds or hard fruits like nuts. (f) Try to recognise various types of trees, shrubs, herbs, etc. Make lists of plants from different places in the forest and of different layers. You may not be able to name all the plants, but it is worth recording and seeing where they grow. Make a record of approximate heights of plants, crown shape, bark texture, leaf size, and flower colour. (g) Learn to recognise the animal’s droppings. (h) Interview the forest officials and the people of surrounding vil lages and other visitors. You must never collect birds’ eggs, and their nests should never be disturbed. You can read more on the following website: www.wild-india.com Did you know? In India the area under forest cover is about 21% of the total area. It had steadily been falling since independence. But people now seem to have realised the importance of the forest cover. Reports suggest that the area under forest cover has slightly increased in recent years. FORESTS: OUR LIFELINE 155 Reprint 2024-25