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Human Intervention i in Natural a, Phenomena, , , , , , ,inisrich in natural resources. Many of these | You will learn about, , r@s0UrceS are essential to our survival, * Forests :, eae, , iythe natural resources from the following ee, , S = a, ation and write one use for each one of them,

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FORESTS, Forests are a valuable natural resour, are beneficial to human beings andt, , Deforestation refers to the continual degra, causes. The main causes of deforestation are as follows., , Deforestation may have, many adverse effects, , on the environment,, including human beings., , The following are some of the ways in which forests, ce. The, , he environment., ants, animals, birds,, , eded for survival. They also absorb carbon dioxide, is ne, , help to maintain a balance of these gases., : and medicines from forests,, , g soil erosion and landslides,, , and insects., Forests provide habitat to a large number of pl, Trees release oxygen, which i, released by animals. Thus, the 7, We obtain useful products such as timber, gum, papel,, , she, in, The roots of trees help to hold the soil in place, prevent ° rn anehitielag Si, Dead plants and trees decompose to form humus, which help, , Sean dation of forests due to natural or human-related, Te, Commercial logging to provide wood for furniture, A, houses, building materials, and other commercial, products, , Rapid urbanization resulting in the loss of forests to, make way for towns and cities, , Destruction of forests for conversion to agricultural, land [Fig. 17.1 (a)]., , Overgrazing by cattle, , , , , Destruction of forests for mining of economically, important minerals, , Felling of forests for, firewood [{Fig. 17.1(b)], and for making paper, , The roots of trees, hold the soil together., Therefore, the loss, , of forests will cause, soil erosion. Gradual, erosion can cause the, Soil to lose its fertility, leading to desertification., , , , (a) Conversion of forests to agricultural land, , (b) Requirement of wood, Fig. 17.1 Main causes of deforestation, , Since forests provide homes to many living organisms, their loss will result in, destruction of the natural habitat of many plants, animals, and birds

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—E——————___————————, , « The felling of trees wi, in the atmosphere, si, , thus maintaining th, atmosphere will Cal h, ere., + Plants also play a major role in maintaining the moisture content of the elena to, Deforestation will therefore result in the atmosphere getting drier, hence lea, reduced rainfall., , ioxide and oxygen, Il result in the imbalance of carbon dioxide x by animal, ce plants take in the carbon dioxide releas dioxide in the, © balance. An increase in the amount of carbon, use global warming., , + The roots of tree, heavy rains, Lac, , in, S also absorb rainwater and hence check the flow of water on = —, k of forest cover will therefore lead to soil erosion, floods, and lan, , , , , , yed an impor, Mrs Indira Gand, , La 15-year ban o, , , , , , , onserving Forests, , Here are some Practices that could help in conserving our forests., * Trees should be planted on a lar:, is called afforestation. When thi, , , , Ge scale on available land. Largeis is done on deforested lands, iti, More forest reserves and botanical gardens should be establish, Allowing animals to graze on the same patch of lan, , id for a long period of time is called, overgrazing. Minimizing overgrazing will go along Way in preventing farmlands from, turning barren., , scale planting of Saplings, s called reforestation,, ed., , Measures should be taken to prevent and control forest fires,, , Awareness programmes could be conducted by school children and various, organizations to promote the need to use our forest resources judiciously. Print and, television advertisements are also an effective, , medium., , i i ined from wood pulp, the, + Since paper is obtaine, recycling of paper will also help conserve trees to, some extent.

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Fatt iy the blanks with the correct wore, , 1 Deat pants and animay Geounpogs bo fin (hurviuaforest), , ~ (ON Raper) ia obtained fom wood pulp, , ~ TAROre state Reforestation) fa the lige-ecate planting of saplings on, , we ee, , ehonea tad tandd., Loss of bvast can Cause soi (conservationaroalon), , ~ (anta’Animala) play a Major role in maintaining the moisture éontent, Of the atmosphern, , Write T tor the True and F tor the Falee atatomonta, Correct the falae statements,, VA docrease i amount ot carbon diavide WW atmosphere will cause global warming, , 2. Trees release carbon Dorie and absorb oxygen daring photosyntheals,, , SX Towns and oties Provide habitat to a large number of planta, animale, birds, and Inagets,, , he, , , , , , , , , , FOSSIL FUELS,, , As you have learnt in Chapter 5, fossil fuels are formed from the burled remains of plants, and animals over a period of millions of years, Coal, petroleum, and natural gas are some, examples of fossil fuels, Fossil fuels are non-renewable energy sources, |.e., they are, , present in a limited quantity and cannot renew or replenish themselves over a short perlod, of time., , Over-extraction of Fossil Fuels, , Fossil fuels play a major role in generating energy for the world today, Their varied uses, , have led to their over-extraction. The major consequences of over-extraction of fossil fuels, are given below., , Exhaustion of existing reserves The over-extraction of fossil fuels Is slowly depleting the, , Earth of these resources. An energy crisis in the Immediate future Is a distinct possibility if, the present rate of consumption of fossil fuels is not brought under control., , Air pollution When coal and petroleum Products are burnt as fuel, they give off carbon, dioxide, a greenhouse gas that leads to global warming. They also give off pollutants such, as carbon monoxide, nitrogen oxides, sulphur oxides, particulate matter such as mineral, ash or fly ash, and unburnt hydrocarbons that pollute the air. Some of these gases combine, with water vapour in the air and form droplets that fall to the Earth as weak forms of, sulphuric and nitric acid, called acid rain., , Threat to organisms Coal contains poisonous metals such as ar., , senic and mercury,, which are dangerous if released into the environment, Mercury th, , at is released into the air, , settles in water over time. It then enters the bodies of fish and shellfish and can be harmful, to animals and people who eat them.

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Pee o, , nserving Fossil Fuels, , pcannot completely stop the use of fossil fuels but we can cut down our dependence, athem. In order to conserve fossil fuels, we can instead use renewable energy sources., enewable energy sources are ener., , gy sources that are present in unlimited quantities and, gnrenew or Ii eplenish themselves over a short period of time. These energy sources, such as, glar energy, Wind energy,, , nuclear energy, and biomass energy, will not only help conserve, yssil fuels, but will also he’, , Ip prevent Pollution, and thus safeguard the environment., ome renewable sources of energy are discussed below,, , , , , , Wind energy Energy of the, , wind has been used since ancient, times to move ships, pump water,, and grind corn. These days, huge Plants, this energy is utilized to, wind turbines are used to move produce heat energy, which is, turbines, which drive generators used to make steam for driving, and produce electricity. generators,, , Hydroelectric energy Energy, derived from flowing water in, water bodies such as rivers is used, by dams to drive generators to, produce electricity., , Nuclear energy This is released, by splitting or merging together, nuclei of atoms. In nuclear power, , , , Solar energy This is utilized with the help of solar, panels and solar cells. Solar panels convert solar, energy into heat and light energy, while solar cells, Convert it to electrical energy., , Biomass energy Biomass refers to organic matter,, such as plant and animal waste. Dung cakes are a form, of biomass that is used as a source of energy in rural, parts of India. Biomass is also used to produce energy,, in the form of biogas, which is then supplied via, pipelines to houses for use as cooking fuel., , , , errata mrt remem, ————