Copy of environmental studies

The need for sustainable lifestyles: The qual- 2.2.3 Renewable resources ity of human life and the quality of ecosystems on earth are indicators of the sustainable use of Though water and biological living resources are resources. There are clear indicators of sustain- considered renewable. They are in fact renew- able lifestyles in human life. able only within certain limits. They are linked to natural cycles such as the water cycle. • Increased longevity • Fresh water (even after being used) is evapo- • An increase in knowledge rated by the sun’s energy, forms water vapour and is reformed in clouds and falls • An enhancement of income. to earth as rain. However, water sources can be overused or wasted to such an ex- These three together are known as the ‘Human tent that they locally run dry. Water sources development index’. can be so heavily polluted by sewage and toxic substances that it becomes impossible The quality of the ecosystems have indicators to use the water. that are more difficult to assess. • Forests, once destroyed take thousands of • A stabilized population. years to regrow into fully developed natu- ral ecosystems with their full complement • The long term conservation of biodiversity. of species. Forests thus can be said to be- have like non-renewable resources if over- • The careful long-term use of natural re- used. sources. • Fish are today being over-harvested until the • The prevention of degradation and pollu- catch has become a fraction of the original tion of the environment. resource and the fish are incapable of breed- ing successfully to replenish the population. 2.2.2 Non-renewable resources • The output of agricultural land if misman- aged drops drastically. These are minerals that have been formed in the lithosphere over millions of years and con- • When the population of a species of plant stitute a closed system. These non-renewable or animal is reduced by human activities, resources, once used, remain on earth in a dif- until it cannot reproduce fast enough to ferent form and, unless recycled, become waste maintain a viable number, the species be- material. comes extinct. Non-renewable resources include fossil fuels • Many species are probably becoming extinct such as oil and coal, which if extracted at the without us even knowing, and other linked present rate, will soon be totally used up. The species are affected by their loss. end products of fossil fuels are in the form of heat and mechanical energy and chemical com- pounds, which cannot be reconstituted as a re- source. 22 Environmental Studies for Undergraduate Courses Chapter2.p65 22 4/9/2004, 5:07 PM

The Dodo of Madagascar and the Cheetah a) Forest Resources in India are well known examples of extinct species. What is however not generally rec- Use and overexploitation: Scientists estimate ognized is that thousands of extinctions of that India should ideally have 33 percent of its small plants and animals are occurring every land under forests. Today we have only about year due to loss of their habitat. Over har- 12 percent. Thus we need not only to protect vesting and poaching threaten the existence existing forests but also to increase our forest of many others. cover. Activity 3: Utilisation of resources People who live in or near forests know the value of forest resources first hand because their lives The use of a resource begins with its collec- and livelihoods depend directly on these re- tion, its processing into a useable product, sources. However, the rest of us also derive great and transport through a delivery system, benefits from the forests which we are rarely to the consumer who uses it. It also involves aware of. The water we use depends on the disposal of the waste products produced at existence of forests on the watersheds around each step. Each step in resource use can af- river valleys. Our homes, furniture and paper are fect the environment for better or worse. made from wood from the forest. We use many The control of these steps is known as en- medicines that are based on forest produce. And vironmental management. we depend on the oxygen that plants give out and the removal of carbon dioxide we breathe Think of a resource you use and track it out from the air. through these steps. Forests once extended over large tracts of our Eg. The cotton in the clothes you are wear- country. People have used forests in our coun- ing. At each step note: try for thousands of years. As agriculture spread the forests were left in patches which were con- • What other resources are needed at this trolled mostly by tribal people. They hunted ani- step to move the resource you chose to mals and gathered plants and lived entirely on the next? forest resources. Deforestation became a major concern in British times when a large amount • What waste products are generated at of timber was extracted for building their ships. that step? This led the British to develop scientific forestry in India. They however alienated local people • How are they likely to be disposed off? by creating Reserved and Protected Forests which curtailed access to the resources. This led • What pollutants are generated in the to a loss of stake in the conservation of the for- process? ests which led to a gradual degradation and fragmentation of forests across the length and Natural Resources breadth of the country. Another period of overutilisation and forest deg- radation occurred in the early period following independence as people felt that now that the British had gone they had a right to using our forests in any way we pleased. The following 23 Chapter2.p65 23 4/9/2004, 5:07 PM

FOREST FUNCTIONS Watershed protection: • Reduce the rate of surface run-off of water. • Prevent flash floods and soil erosion. • Produces prolonged gradual run-off and thus prevent effects of drought. Atmospheric regulation: • Absorption of solar heat during evapo-transpiration. • Maintaining carbon dioxide levels for plant growth. • Maintaining the local climatic conditions. Erosion control: • Holding soil (by preventing rain from directly washing soil away). Land bank: • Maintenance of soil nutrients and structure. Local use - Consumption of forest produce by local people who collect it for subsistence – (Consumptive use) • Food - gathering plants, fishing, hunting from the forest. (In the past when wildlife was plentiful, people could hunt and kill animals for food. Now that populations of most wildlife species have diminished, continued hunting would lead to extinction.) • Fodder - for cattle. • Fuel wood and charcoal for cooking, heating. • Poles - building homes especially in rural and wilderness areas. • Timber – household articles and construction. • Fiber - weaving of baskets, ropes, nets, string, etc. • Sericulture – for silk. • Apiculture - bees for honey, forest bees also pollinate crops. • Medicinal plants - traditionally used medicines, investigating them as potential source for new modern drugs. Market use - (Productive use) • Most of the above products used for consumptive purposes are also sold as a source of income for supporting the livelihoods of forest dwelling people. • Minor forest produce - (non-wood products): Fuelwood, fruit, gum, fiber, etc. which are collected and sold in local markets as a source of income for forest dwellers. • Major timber extraction - construction, industrial uses, paper pulp, etc. Timber extraction is done in India by the Forest Department, but illegal logging continues in many of the forests of India and the world. 24 Environmental Studies for Undergraduate Courses Chapter2.p65 24 4/9/2004, 5:07 PM

years saw India’s residual forest wealth dwindle CASE STUDY sharply. Timber extraction continued to remain the Forest Department’s main concern up to the Joint Forest Management 1970s. The fact that forest degradation and deforestation was creating a serious loss of the The need to include local communities in important functions of the forest began to over- Forest Management has become a growing ride its utilisation as a source of revenue from concern. Local people will only support timber. greening an area if they can see some eco- nomic benefit from conservation. An infor- Deforestation: Where civilizations have looked mal arrangement between local communi- after forests by using forest resources cautiously, ties and the Forest Department began in they have prospered, where forests were de- 1972, in Midnapore District of West Bengal. stroyed, the people were gradually impover- JFM has now evolved into a formal agree- ished. Today logging and mining are serious ment which identifies and respects the local causes of loss of forests in our country and all community’s rights and benefits that they over the world. Dams built for hydroelectric need from forest resources. Under JFM power or irrigation have submerged forests and schemes, Forest Protection Committees from have displaced tribal people whose lives are local community members are formed. They closely knit to the forest. This has become a se- participate in restoring green cover and pro- rious cause of concern in India. tect the area from being over exploited. One of India’s serious environmental problems ranges from 25 per cent in Kerala to 100 per is forest degradation due to timber extraction cent in Andhra Pradesh, 50 per cent in Gujarat, and our dependence on fuelwood. A large num- Maharashtra, Orissa and Tripura. In many States ber of poor rural people are still highly depen- 25 per cent of the revenue is used for village dent on wood to cook their meals and heat their development. In many States non-timber forest homes. We have not been able to plant enough products (NTFPs) are available for people free trees to support the need for timber and of cost. fuelwood. Some States have stopped grazing completely; The National Forest Policy of 1988 now gives an some have rotational grazing schemes which added importance to JFM. Another resolution have helped in forest regeneration. in 1990 provided a formal structure for com- munity participation though the formation of Timber extraction, mining and dams are in- Village Forest Committees. Based on these ex- variably parts of the needs of a developing coun- periences, new JFM guidelines were issued in try. If timber is overharvested the ecological func- 2000. This stipulates that at least 25 per cent of tions of the forest are lost. Unfortunately for- the income from the area must go to the com- ests are located in areas where there are rich munity. From the initiation of the program, un- mineral resources. Forests also cover the steep til 2002, there were 63,618 JFM Committees embankments of river valleys, which are ideally managing over 140,953 sq. km of forest under suited to develop hydel and irrigation projects. JFM in 27 States in India. Thus there is a constant conflict of interests be- The States have tried a variety of approaches to 25 JFM. The share for village forest committees Natural Resources Chapter2.p65 25 4/9/2004, 5:07 PM

tween the conservation interests of environmen- places enormous demands on the world’s lim- tal scientists and the Mining and Irrigation De- ited freshwater supply. The total annual fresh- partments. What needs to be understood is that water withdrawals today are estimated at 3800 long-term ecological gains cannot be sacrificed cubic kilometers, twice as much as just 50 years for short-term economic gains that unfortu- ago (World Commission on Dams, 2000). Stud- nately lead to deforestation. These forests where ies indicate that a person needs a minimum of development projects are planned, can displace 20 to 40 liters of water per day for drinking and thousands of tribal people who lose their homes sanitation. More than one billion people world- when these plans are executed. This leads to wide have no access to clean water, and to many high levels of suffering for which there is rarely more, supplies are unreliable. a satisfactory answer. Local conflicts are already spreading to states. b) Water resources Eg. Karnataka and Tamil Nadu over the waters of the Krishna. The water cycle, through evaporation and pre- India is expected to face critical levels of water cipitation, maintains hydrological systems which stress by 2025. At the global level 31 countries form rivers and lakes and support in a variety of are already short of water and by 2025 there aquatic ecosystems. Wetlands are intermediate will be 48 countries facing serious water short- forms between terrestrial and aquatic ecosys- ages. The UN has estimated that by the year tems and contain species of plants and animals 2050, 4 billion people will be seriously affected that are highly moisture dependent. All aquatic by water shortages. This will lead to multiple ecosystems are used by a large number of people conflicts between countries over the sharing of for their daily needs such as drinking water, water. Around 20 major cities in India face washing, cooking, watering animals, and irri- chronic or interrupted water shortages. There gating fields. The world depends on a limited are 100 countries that share the waters of 13 quantity of fresh water. Water covers 70% of large rivers and lakes. The upstream countries the earth’s surface but only 3% of this is fresh could starve the downstream nations leading to water. Of this, 2% is in polar ice caps and only political unstable areas across the world. Ex- 1% is usable water in rivers, lakes and subsoil amples are Ethopia, which is upstream on the aquifers. Only a fraction of this can be actually Nile and Egypt, which is downstream and highly used. At a global level 70% of water is used for dependent on the Nile. International accords agriculture about 25% for industry and only 5% that will look at a fair distribution of water in for domestic use. However this varies in differ- such areas will become critical to world peace. ent countries and industrialized countries use a India and Bangladesh already have a negotiated greater percentage for industry. India uses 90% agreement on the water use of the Ganges. for agriculture, 7% for industry and 3% for domestic use. Overutilization and pollution of surface and groundwater: With the growth of human One of the greatest challenges facing the world population there is an increasing need for larger in this century is the need to rethink the overall amounts of water to fulfill a variety of basic management of water resources. The world needs. Today in many areas this requirement population has passed the 6 billion mark. Based cannot be met. Overutilization of water occurs on the proportion of young people in develop- at various levels. Most people use more water ing countries, this will continue to increase sig- than they really need. Most of us waste water nificantly during the next few decades. This 26 Environmental Studies for Undergraduate Courses Chapter2.p65 26 4/9/2004, 5:07 PM

during a bath by using a shower or during wash- Global climate change: Changes in climate at ing of clothes. Many agriculturists use more a global level caused by increasing air pollution water than necessary to grow crops. There are have now begun to affect our climate. In some many ways in which farmers can use less water regions global warming and the El Nino winds without reducing yields such as the use of drip have created unprecedented storms. In other irrigation systems. areas, they lead to long droughts. Everywhere the ‘greenhouse effect’ due to atmospheric Agriculture also pollutes surface water and un- pollution is leading to increasingly erratic and derground water stores by the excessive use of unpredictable climatic effects. This has seriously chemical fertilizers and pesticides. Methods such affected regional hydrological conditions. as the use of biomass as fertilizer and non toxic pesticides such as neem products and using in- Floods: Floods have been a serious environmen- tegrated pest management systems reduces the tal hazard for centuries. However, the havoc agricultural pollution of surface and ground raised by rivers overflowing their banks has be- water. come progressively more damaging, as people have deforested catchments and intensified use Industry tends to maximise short-term economic of river flood plains that once acted as safety gains by not bothering about its liquid waste valves. Wetlands in flood plains are nature’s and releasing it into streams, rivers and the sea. flood control systems into which overfilled riv- In the longer term, as people become more con- ers could spill and act like a temporary sponge scious of using ‘green products’ made by holding the water, and preventing fast flowing ecosensitive industries, the polluter’s products water from damaging surrounding land. may not be used. The polluting industry that does not care for the environment and pays off Deforestation in the Himalayas causes floods bribes to get away from the cost needed to use that year after year kill people, damage crops effluent treatment plants may eventually be and destroy homes in the Ganges and its tribu- caught, punished and even closed down. Public taries and the Bramhaputra. Rivers change their awareness may increasingly put pressures on course during floods and tons of valuable soil is industry to produce only eco-friendly products lost to the sea. As the forests are degraded, rain- which are already gaining in popularity. water no longer percolates slowly into the sub- soil but runs off down the mountainside bear- As people begin to learn about the serious health ing large amounts of topsoil. This blocks rivers hazards caused by pesticides in their food, pub- temporarily but gives way as the pressure lic awareness can begin putting pressures on mounts allowing enormous quantities of water farmers to reduce the use of chemicals that are to wash suddenly down into the plains below. injurious to health. There, rivers swell, burst their banks and flood waters spread to engulf peoples’ farms and CASE STUDY homes. Water pollution - Nepal Drought: In most arid regions of the world the rains are unpredictable. This leads to periods The Narayani River of Nepal has been pol- when there is a serious scarcity of water to drink, luted by factories located on its bank. This use in farms, or provide for urban and industrial has endangered fish, dolphins, crocodiles and use. Drought prone areas are thus faced with other flora and fauna of the region. 27 Natural Resources Chapter2.p65 27 4/9/2004, 5:07 PM

irregular periods of famine. Agriculturists have water table drops and vegetation suffers. This no income in these bad years, and as they have soil and water management and afforestation no steady income, they have a constant fear of are long-term measures that reduce the impact droughts. India has ‘Drought Prone Areas De- of droughts. velopment Programs’, which are used in such areas to buffer the effects of droughts. Under Water for Agriculture and Power Genera- these schemes, people are given wages in bad tion: India’s increasing demand for water for years to build roads, minor irrigation works and intensive irrigated agriculture, for generating plantation programs. electricity, and for consumption in urban and industrial centers, has been met by creating large Drought has been a major problem in our coun- dams. Irrigated areas increased from 40 million try especially in arid regions. It is an unpredict- ha. in 1900 to 100 million ha. in 1950 and to able climatic condition and occurs due to the 271 million ha. by 1998. Dams support 30 to failure of one or more monsoons. It varies in 40% of this area. frequency in different parts of our country. While it is not feasible to prevent the failure of Although dams ensure a year round supply of the monsoon, good environmental manage- water for domestic use, provide extra water for ment can reduce its ill effects. The scarcity of agriculture, industry, hydropower generation, water during drought years affects homes, ag- they have several serious environmental prob- riculture and industry. It also leads to food short- lems. They alter river flows, change nature’s ages and malnutrition which especially affects flood control mechanisms such as wetlands and children. flood plains, and destroy the lives of local people and the habitats of wild plant and animal spe- Several measures can be taken to minimise the cies. serious impacts of a drought. However this must be done as a preventive measure so that if the Irrigation to support cash crops like sugarcane monsoons fail its impact on local people’s lives produces an unequal distribution of water. Large is minimised. landholders on the canals get the lion’s share of water, while poor, small farmers get less and In years when the monsoon is adequate, we use are seriously affected. up the good supply of water without trying to conserve it and use the water judiciously. Thus Sustainable water management: ‘Save wa- during a year when the rains are poor, there is ter’ campaigns are essential to make people no water even for drinking in the drought area. everywhere aware of the dangers of water scar- city. A number of measures need to be taken One of the factors that worsens the effect of for the better management of the world’s wa- drought is deforestation. Once hill slopes are ter resources. These include measures such as: denuded of forest cover the rainwater rushes down the rivers and is lost. Forest cover permits • Building several small reservoirs instead of water to be held in the area permitting it to few mega projects. seep into the ground. This charges the under- ground stores of water in natural aquifers. This • Develop small catchment dams and protect can be used in drought years if the stores have wetlands. been filled during a good monsoon. If water from the underground stores is overused, the 28 Environmental Studies for Undergraduate Courses Chapter2.p65 28 4/9/2004, 5:07 PM

• Soil management, micro catchment devel- have built around 57% of the world’s large opment and afforestation permits recharg- dams. ing of underground aquifers thus reducing the need for large dams. Dams problems • Treating and recycling municipal waste • Fragmentation and physical transformation water for agricultural use. of rivers. • Preventing leakages from dams and canals. • Serious impacts on riverine ecosystems. • Preventing loss in Municipal pipes. • Social consequences of large dams due to displacement of people. • Effective rain water harvesting in urban environments. • Water logging and salinisation of surround- ing lands. • Water conservation measures in agriculture such as using drip irrigation. • Dislodging animal populations, damaging their habitat and cutting off their migration • Pricing water at its real value makes people routes. use it more responsibly and efficiently and reduces water wasting. • Fishing and travel by boat disrupted. • In deforested areas where land has been • The emission of green house gases from degraded, soil management by bunding reservoirs due to rotting vegetation and along the hill slopes and making ‘nala’ plugs, carbon inflows from the catchment is a re- can help retain moisture and make it pos- cently identified impact. sible to re-vegetate degraded areas. Managing a river system is best done by leaving Large dams have had serious impacts on the its course as undisturbed as possible. Dams and lives, livelihoods, cultures and spiritual existence canals lead to major floods in the monsoon and of indigenous and tribal peoples. They have suf- the drainage of wetlands seriously affects areas fered disproportionately from the negative im- that get flooded when there is high rainfall. pacts of dams and often been excluded from sharing the benefits. In India, of the 16 to 18 Dams: Today there are more than 45,000 large million people displaced by dams, 40 to 50% dams around the world, which play an impor- were tribal people, who account for only 8% of tant role in communities and economies that our nation’s one billion people. harness these water resources for their economic development. Current estimates suggest some Conflicts over dams have heightened in the last 30-40% of irrigated land worldwide relies on two decades because of their social and envi- dams. Hydropower, another contender for the ronmental impacts and failure to achieve tar- use of stored water, currently supplies 19% of gets for sticking to their costs as well as achiev- the world’s total electric power supply and is ing promised benefits. Recent examples show used in over 150 countries. The world’s two how failure to provide a transparent process that most populous countries – China and India – includes effective participation of local people has prevented affected people from playing an Natural Resources 29 Chapter2.p65 29 4/9/2004, 5:07 PM

active role in debating the pros and cons of the Activity 4: project and its alternatives. The loss of tradi- tional, local controls over equitable distribution How much water is needed by one person? remains a major source of conflict. Several international agencies and experts have proposed that 50 liters per person per In India, a national assessment of dam day covers basic human water requirements projects cleared in the 1980s and 90s shows for drinking, sanitation, bathing and food that in 90% of cases the project authorities preparation. Estimate your average daily have not fulfilled the environmental condi- consumption. tions under which environmental clearance was given by the GOI under the EPA of 1986. c) Mineral Resources CASE STUDY A mineral is a naturally occurring substance of definite chemical composition and identifiable Sardar Sarovar Project physical properties. An ore is a mineral or com- bination of minerals from which a useful sub- The World Bank’s withdrawal from the stance, such as a metal, can be extracted and Sardar Sarovar Project in India in 1993 was used to manufacture a useful product. a result of the demands of local people threatened with the loss of their livelihoods Minerals are formed over a period of millions of and homes in the submergence area. years in the earth’s crust. Iron, aluminum, zinc, manganese and copper are important raw ma- This dam in Gujarat on the Narmada has dis- terials for industrial use. Important non-metal placed thousands of tribal folk, whose lives resources include coal, salt, clay, cement and and livelihoods were linked to the river, the silica. Stone used for building material, such as forests and their agricultural lands. While granite, marble, limestone, constitute another they and the fishermen at the estuary, have category of minerals. Minerals with special prop- lost their homeland, rich farmers down- erties that humans value for their aesthetic and stream will get water for agriculture. The ornamental value are gems such as diamonds, question is why should the local tribals be emeralds, rubies. The luster of gold, silver and made homeless, displaced and relocated to platinum is used for ornaments. Minerals in the benefit other people? Why should the less form of oil, gas and coal were formed when fortunate be made to bear the costs of de- ancient plants and animals were converted into velopment for better off farmers? It is a ques- underground fossil fuels. tion of social and economic equity as well as the enormous environmental losses, includ- Minerals and their ores need to be extracted ing loss of the biological diversity of the in- from the earth’s interior so that they can be undated forests in the Narmada valley. used. This process is known as mining. Mining operations generally progress through four stages: (1) Prospecting: Searching for minerals. (2) Exploration: Assessing the size, shape, lo- cation, and economic value of the deposit. 30 Environmental Studies for Undergraduate Courses Chapter2.p65 30 4/9/2004, 5:07 PM

(3) Development: Work of preparing access to CASE STUDY the deposit so that the minerals can be ex- tracted from it. Sariska Tiger Reserve, Rajasthan (4) Exploitation: Extracting the minerals from The Forest Department has leased land for the mines. mining in the Sariska Tiger Reserve area by denotifying forest areas. The local people In the past, mineral deposits were discovered have fought against the mining lobby, and by prospectors in areas where mineral deposits have filed a Public Interest Litigation in the in the form of veins were exposed on the sur- Supreme Court in 1991. Rajendra Singh, sec- face. Today, however, prospecting and explo- retary of TBS, points out that as many as 70 ration is done by teams of geologists, mining mines operate in close proximity to the for- engineers, geophysicists, and geochemists who est. work together to discover new deposits. Mod- ern prospecting methods include the use of so- equate ventilation are the greatest hazards. phisticated instruments like GIS to survey and Large explosions have occured in coal mines, study the geology of the area. killing many miners. More miners have suffered from disasters due to the use of explosives in The method of mining has to be determined metal mines. depending on whether the ore or mineral de- posit is nearer the surface or deep within the Mining poses several long-term occupational earth. The topography of the region and the hazards to the miners. Dust produced during physical nature of the ore deposit is studied. mining operations is injurious to health and causes a lung disease known as black lung, or Mines are of two types – surface (open cut or pneumoconiosis. Fumes generated by incom- strip mines) or deep or shaft mines. Coal, met- plete dynamite explosions are extremely poison- als and non-metalliferous minerals are all mined ous. Methane gas, emanating from coal strata, differently depending on the above criteria. The is hazardous to health although not poisonous method chosen for mining will ultimately de- in the concentrations usually encountered in pend on how maximum yield may be obtained mine air. Radiation is a hazard in uranium under existing conditions at a minimum cost, mines. with the least danger to the mining personnel. Environmental problems: Mining operations Most minerals need to be processed before they are considered one of the main sources of envi- become usable. Thus ‘technology’ is dependent ronmental degradation. The extraction of all on both the presence of resources and the en- these products from the lithosphere has a vari- ergy necessary to make them ‘usable’. ety of side effects. Depletion of available land due to mining, waste from industries, conver- Mine safety: Mining is a hazardous occupa- sion of land to industry and pollution of land, tion, and the safety of mine workers is an im- water and air by industrial wastes, are environ- portant environmental consideration of the in- mental side effects of the use of these non-re- dustry. Surface mining is less hazardous than newable resources. Public awareness of this underground mining. Metal mining is less haz- ardous than coal mining. In all underground 31 mines, rock and roof falls, flooding, and inad- Natural Resources Chapter2.p65 31 4/9/2004, 5:07 PM

problem is of a global nature and government irrigation. The Green Revolution of the 60’s re- actions to stem the damage to the natural envi- duced starvation in the country. However many ronment have led to numerous international of the technologies we have used to achieve agreements and laws directed toward the pre- this are now being questioned. vention of activities and events that may ad- versely affect the environment. • Our fertile soils are being exploited faster than they can recuperate. d) Food resources • Forests, grasslands and wetlands have been converted to agricultural use, which has led Today our food comes almost entirely from ag- to serious ecological questions. riculture, animal husbandry and fishing. Al- though India is self-sufficient in food produc- • Our fish resources, both marine and inland, tion, it is only because of modern patterns of show evidence of exhaustion. agriculture that are unsustainable and which pollute our environment with excessive use of • There are great disparities in the availability fertilizers and pesticides. of nutritious food. Some communities such as tribal people still face serious food prob- The FAO defines sustainable agriculture as that lems leading to malnutrition especially which conserves land, water and plant and ani- among women and children. mal genetic resources, does not degrade the environment and is economically viable and so- These issues bring in new questions as to how cially acceptable. Most of our large farms grow demands will be met in future even with a slow- single crops (monoculture). If this crop is hit by ing of population growth. Today the world is a pest, the entire crop can be devastated, leav- seeing a changing trend in dietary habits. As ing the farmer with no income during the year. living standards are improving, people are eat- On the other hand, if the farmer uses traditional ing more non-vegetarian food. As people varieties and grows several different crops, the change from eating grain to meat, the world’s chance of complete failure is lowered consider- demand for feed for livestock based on agricul- ably. Many studies have shown that one can ture increases as well. This uses more land per use alternatives to inorganic fertilizers and pes- unit of food produced and the result is that the ticides. This is known as Integrated Crop Man- world’s poor do not get enough to eat. agement. Women play an extremely vital role in food pro- World food problems: In many developing duction as well as cooking the meal and feed- countries where populations are expanding rap- ing children. In most rural communities they have idly, the production of food is unable to keep the least exposure to technical training and to pace with the growing demand. Food produc- health workers trained in teaching/learning on tion in 64 of the 105 developing countries is issues related to nutritional aspects. Women and lagging behind their population growth levels. girls frequently receive less food than the men. These countries are unable to produce more These disparities need to be corrected. food, or do not have the financial means to im- port it. India is one of the countries that have In India there is a shortage of cultivable produc- been able to produce enough food by cultivat- tive land. Thus farm sizes are too small to sup- ing a large proportion of its arable land through port a family on farm produce alone. With each generation, farms are being subdivided further. 32 Environmental Studies for Undergraduate Courses Chapter2.p65 32 4/9/2004, 5:07 PM

Poor environmental agricultural practices such to an improved flow of food across national as slash and burn, shifting cultivation, or ‘rab’ borders from those who have surplus to those (woodash) cultivation degrade forests. who have a deficit in the developing world is another issue that is a concern for planners who Globally 5 to 7 million hectares of farmland is deal with International trade concerns. ‘Dump- degraded each year. Loss of nutrients and over- ing’ of underpriced foodstuffs produced in the use of agricultural chemicals are major factors developed world, onto markets in undeveloped in land degradation. Water scarcity is an impor- countries undermines prices and forces farmers tant aspect of poor agricultural outputs. Salin- there to adopt unsustainable practices to com- ization and water logging has affected a large pete. amount of agricultural land worldwide. Loss of genetic diversity in crop plants is another Fisheries: Fish is an important protein food in issue that is leading to a fall in agricultural pro- many parts of the world. This includes marine duce. Rice, wheat and corn are the staple foods and fresh water fish. While the supply of food of two thirds of the world’s people. As wild rela- from fisheries increased phenomenally between tives of crop plants in the world’s grasslands, 1950 and 1990, in several parts of the world wetlands and other natural habitats are being fish catch has since dropped due to overfishing. lost, the ability to enhance traits that are resis- In 1995 FAO reported that 44% of the world’s tant to diseases, salinity, etc. is lost. Genetic fisheries are fully or heavily exploited, 16% are engineering is an untried and risky alternative already overexploited, 6% are depleted, and to traditional cross breeding. only 3% are gradually recovering. Canada had to virtually close down cod fishing in the 1990s Food Security: It is estimated that 18 million due to depletion of fish reserves. people worldwide, most of whom are children, die each year due to starvation or malnutrition, Modern fishing technologies using mechanized and many others suffer a variety of dietary defi- trawlers and small meshed nets lead directly to ciencies. overexploitation, which is not sustainable. It is evident that fish have to breed successfully and The earth can only supply a limited amount of need to have time to grow if the yield has to be food. If the world’s carrying capacity to produce used sustainably. The worst hit are the small tra- food cannot meet the needs of a growing popu- ditional fishermen who are no match for orga- lation, anarchy and conflict will follow. Thus food nized trawlers. security is closely linked with population control through the family welfare program. It is also Loss of Genetic diversity: There are 50,000 linked to the availability of water for farming. known edible plants documented worldwide. Food security is only possible if food is equitably Of these only 15 varieties produce 90% of the distributed to all. Many of us waste a large world’s food. Modern agricultural practices have amount of food carelessly. This eventually places resulted in a serious loss of genetic variability of great stress on our environmental resources. crops. India’s distinctive traditional varieties of rice alone are said to have numbered between A major concern is the support needed for small 30 and 50 thousand. Most of these have been farmers so that they remain farmers rather than lost to the farmer during the last few decades shifting to urban centers as unskilled industrial as multinational seed companies push a few workers. International trade policies in regard commercial types. Natural Resources 33 Chapter2.p65 33 4/9/2004, 5:07 PM

This creates a risk to our food security, as farm- techniques, especially on hill slopes, enhancing ers can loose all their produce due to a rapidly the soil with organic matter, rotating crops and spreading disease. A cereal that has multiple managing watersheds at the micro level are a varieties growing in different locations does not key to agricultural production to meet future permit the rapid spread of a disease. needs. Most importantly food supply is closely linked to the effectiveness of population con- The most effective method to introduce desir- trol programs worldwide. The world needs bet- able traits into crops is by using characteristics ter and sustainable methods of food produc- found in the wild relatives of crop plants. As the tion which is an important aspect of landuse wilderness shrinks, these varieties are rapidly management. disappearing. Once they are lost, their desirable characteristics cannot be introduced when Alternate food sources: Food can be found necessary in future. Ensuring long-term innovatively produced if we break out of the food security may depend on conserving wild current agricultural patterns. This includes work- relatives of crop plants in National Parks and ing on new avenues to produce food, such as Wildlife Sanctuaries. using forests for their multiple non-wood forest products, which can be used for food if har- If plant genetic losses worldwide are not slowed vested sustainably. This includes fruit, mush- down, some estimates show that as many as rooms, sap, gum, etc. This takes time, as people 60,000 plant species, which accounts for 25% must develop a taste for these new foods. of the world’s total, will be lost by the year 2025. The most economical way to prevent this is by CASE STUDY expanding the network and coverage of our Protected Areas. Collections in germplasm, seed Israel began using drip irrigation systems as banks and tissue culture facilities, are other pos- it is short of water. With this technique, farm- sible ways to prevent extinction but are ex- ers have been able to improve the efficiency tremely expensive. of irrigation by 95%. Over a 20-year period, Israel’s food production doubled without an Scientists now believe that the world will soon increase in the use of water for agriculture. need a second green revolution to meet our future demands of food based on a new ethic In India, some traditional communities in of land and water management that must be urban and semi urban towns used to grow based on values which include environmental their own vegetables in backyards on waste- sensitivity, equity, biodiversity conservation of water from their own homes. Calcutta re- cultivars and insitu preservation of wild relatives leases its waste water into surrounding la- of crop plants. This must not only provide food goons in which fish are reared and the wa- for all, but also work out more equitable distri- ter is used for growing vegetables. bution of both food and water, reduce agricul- tural dependence on the use of fertilizers and Medicines, both traditional and modern, can be pesticides (which have long term ill effects on harvested sustainably from forests. human wellbeing) and provide an increasing Madagaskar’s Rosy Periwinkle used for child- support for preserving wild relatives of crop hood leukemia’s and Taxol from Western Yew plants in Protected Areas. Pollution of water sources, land degradation and desertification must be rapidly reversed. Adopting soil conser- vation measures, using appropriate farming 34 Environmental Studies for Undergraduate Courses Chapter2.p65 34 4/9/2004, 5:07 PM

from the American Northwest as an anticancer food, water, fuel drug are examples of forest products used ex- and shelter. The tensively in modern medicine. Without care, sun’s rays power commercial exploitation can lead to early extinc- the growth of tion of such plants. plants, which form our food material, Using unfamiliar crops such as Nagli, which are give off oxygen grown on poor soil on hill slopes is another op- which we breathe in and take up carbon diox- tion. This crop grown in the Western Ghats now ide that we breathe out. Energy from the sun has no market and is thus rarely grown. Only evaporates water from oceans, rivers and lakes, local people use this nutritious crop themselves. to form clouds that turn into rain. Today’s fossil It is thus not as extensively cultivated as in the fuels were once the forests that grew in prehis- past. Popularising this crop could add to food toric times due to the energy of the sun. availability from marginal lands. Several crops can be grown in urban settings, including veg- Chemical energy, contained in chemical com- etables and fruit which can be grown on waste pounds is released when they are broken down household water and fertilizers from by animals in the presence of oxygen. In India, vermicomposting pits. manual labour is still extensively used to get work done in agricultural systems, and domestic ani- Several foods can be popularized from yet un- mals used to pull carts and ploughs. Electrical used seafood products such as seaweed as long energy produced in several ways, powers trans- as this is done at sustainable levels. Educating port, artificial lighting, agriculture and industry. women about nutrition, who are more closely This comes from hydel power based on the involved with feeding the family, is an impor- water cycle that is powered by the sun’s energy tant aspect of supporting the food needs of that supports evaporation, or from thermal many developing countries. power stations powered by fossil fuels. Nuclear energy is held in the nucleus of an atom and is Integrated Pest Management includes preserv- now harnessed to develop electrical energy. ing pest predators, using pest resistant seed varieties and reducing the use of chemical fer- We use energy for household use, agriculture, tilizers. production of industrial goods and for running transport. Modern agriculture uses chemical e) Energy resources fertilizers, which require large amounts of en- ergy dur- Energy is defined by physicists as the ca- ing their pacity to do work. Energy is found on our manufac- planet in a variety of forms, some of which ture. In- are immediately useful to do work, while oth- dustry ers require a process of transformation. uses en- ergy to The sun is the primary energy source in our lives. power We use it directly for its warmth and through manufacturing units and the urban complexes various natural processes that provide us with that support it. Energy-demanding roads and railway lines are built to transport products from Natural Resources place to place and to reach raw materials in mines and forests. 35 Chapter2.p65 35 4/9/2004, 5:07 PM

No energy related technology is completely ‘risk In 1998, the World Resources Institute found free’ and unlimited demands on energy increase that the average American uses 24 times the this risk factor many fold. All energy use creates energy used by an Indian. heat and contributes to atmospheric tempera- ture. Many forms of energy release carbon di- Between 1950 and 1990, the world’s energy oxide and lead to global warming. Nuclear en- needs increased four fold. The world’s demand ergy plants have caused enormous losses to the for electricity has doubled over the last 22 years! environment due to the leakage of nuclear ma- The world’s total primary energy consumption terial. The inability to effectively manage and in 2000 was 9096 million tons of oil. A global safely dispose of nuclear waste is a serious average per capita that works out to be 1.5 tons global concern. of oil. Electricity is at present the fastest grow- ing form of end-use energy worldwide. By 2005 At present almost 2 billion people worldwide the Asia-Pacific region is expected to surpass have no access to electricity at all. While more North America in energy consumption and by people will require electrical energy, those who 2020 is expected to consume some 40% more do have access to it continue to increase their energy than North America. individual requirements. In addition, a large pro- portion of energy from electricity is wasted dur- For almost 200 years, coal was the primary en- ing transmission as well as at the user level. It is ergy source fuelling the industrial revolution in broadly accepted that long-term trends in en- the 19th century. At the close of the 20th cen- ergy use should be towards a cleaner global tury, oil accounted for 39% of the world’s com- energy system that is less carbon intensive and mercial energy consumption, followed by coal less reliant on finite non-renewable energy (24%) and natural gas (24%), while nuclear sources. It is estimated that the currently used (7%) and hydro/renewables (6%) accounted for methods of using renewable energy and non the rest. renewable fossil fuel sources together will be insufficient to meet foreseeable global demands Among the commercial energy sources used in for power generation beyond the next 50 to India, coal is a predominant source accounting 100 years. for 55% of energy consumption estimated in 2001, followed by oil (31%), natural gas (8%), Thus when we use energy wastefully, we are hydro (5%) and nuclear (1%). contributing to a major environmental disaster for our earth. We all need to become respon- In India, biomass (mainly wood and dung) ac- sible energy users. An electrical light that is burn- counts for almost 40% of primary energy sup- ing unnecessarily is a contributor to environmen- ply. While coal continues to remain the domi- tal degradation. nant fuel for electricity generation, nuclear power has been increasingly used since the Growing energy needs: Energy has always 1970s and 1980s and the use of natural gas been closely linked to man’s economic growth has increased rapidly in the 80s and 90s. and development. Present strategies for devel- opment that have focused on rapid economic growth have used energy utilization as an index of economic development. This index however, does not take into account the long-term ill ef- fects on society of excessive energy utilisation. 36 Environmental Studies for Undergraduate Courses Chapter2.p65 36 4/9/2004, 5:07 PM

Types of energy: There are three main types Warming the seas also leads to the death of of energy; those classified as non-renewable; sensitive organisms such as coral. those that are said to be renewable; and nuclear energy, which uses such small quanti- Oil and its environmental impacts: India’s oil ties of raw material (uranium) that supplies are reserves which are being used at present lie off to all effect, limitless. However, this classifica- the coast of Mumbai and in Assam. Most of our tion is inaccurate because several of the renew- natural gas is linked to oil and, because there is able sources, if not used ‘sustainably’, can be no distribution system, it is just burnt off. This depleted more quickly than they can be re- wastes nearly 40% of available gas. The pro- newed. cesses of oil and natural gas drilling, process- ing, transport and utilisation have serious envi- Non renewable energy ronmental consequences, such as leaks in which air and water are polluted and accidental fires To produce electricity from non-renewable re- that may go on burning for days or weeks be- sources the material must be ignited. The fuel is fore the fire can be controlled. During refining placed in a well contained area and set on fire. oil, solid waste such as salts and grease are pro- The heat generated turns water to steam, which duced which also damage the environment. Oil moves through pipes, to turn the blades of a slicks are caused at sea from offshore oil wells, turbine. This converts magnetism into electric- cleaning of oil tankers and due to shipwrecks. ity, which we use in various appliances. The most well-known disaster occurred when the Exxon Non-Renewable Energy Sources: These consist Valdez sank of the mineral based hydrocarbon fuels coal, oil in 1989 and and natural gas, that were formed from ancient birds, sea ot- prehistoric forests. These are called ‘fossil fuels’ ters, seals, because they are formed after plant life is fos- fish and silized. At the present rate of extraction there is other ma- enough coal for a long time to come. Oil and rine life gas resources however are likely to be used up along the within the next 50 years. When these fuels are coast of burnt, they produce waste products that are Alaska was released into the atmosphere as gases such as seriously af- carbon dioxide, oxides of sulphur, nitrogen, and fected. carbon monoxide, all causes of air pollution. These have led to lung problems in an enor- Oil powered vehicles emit carbon dioxide, sul- mous number of people all over the world, and phur dioxide, nitrous oxide, carbon monoxide have also affected buildings like the Taj Mahal and particulate matter which is a major cause and killed many forests and lakes due to acid of air pollution especially in cities with heavy traf- rain. Many of these gases also act like a green fic density. Leaded petrol, leads to neuro dam- house letting sunlight in and trapping the heat age and reduces attention spans. Running petrol inside. This is leading to global warming, a raise vehicles with unleaded fuel has been achieved in global temperature, increased drought in by adding catalytic converters on all the new some areas, floods in other regions, the melting cars, but unleaded fuel contains benzene and of icecaps, and a rise in sea levels, which is slowly butadene which are known to be carcinogenic submerging coastal belts all over the world. compounds. Delhi, which used to have serious Natural Resources 37 Chapter2.p65 37 4/9/2004, 5:07 PM

smog problems due to traffic, has been able to CASE STUDY reduce this health hazard by changing a large number of its vehicles to CNG, which contains Oil related disasters methane. During the Gulf War, oil installations burned Dependence on dwindling fossil fuel resources, for weeks polluting the air with poisonous especially oil, results in political tension, insta- gasses. The fires wasted 5 million barrels of bility and war. At present 65 percent of the oil and produced over a million tons of air- world’s oil reserves are located in the Middle borne pollutants, including sulphur dioxide, East. a major cause of acid rain. The gases moved to a height of 3km and spread as far as In- Coal and its environmental impacts: Coal is dia. Oil also polluted coastlines, killing birds the world’s single largest contributor of green and fish. house gases and is one of the most important causes of global warming. Renewable energy Many coal-based power generation plants are Renewable energy systems use resources that not fitted with devices such as electrostatic pre- are constantly replaced and are usually less pol- cipitators to reduce emissions of suspended par- luting. Examples include hydropower, solar, ticulate matter (SPM) which is a major contribu- wind, and geothermal (energy from the heat tor to air pollution. Burning coal also produces inside the earth). We also get renewable en- oxides of sulphur and nitrogen which, combined ergy from burning trees and even garbage as with water vapour, lead to ‘acid rain’. This kills fuel and processing other plants into biofuels. forest vegetation, and damages architectural heritage sites, pollutes water and affects human One day, all our homes may get their energy health. from the sun or the wind. Your car’s gas tank will use biofuel. Your garbage might contribute Thermal power stations that use coal produce to your city’s energy supply. Renewable energy waste in the form of ‘fly ash’. Large dumps are technologies will improve the efficiency and cost required to dispose off this waste material, while of energy systems. We may reach the point efforts have been made to use it for making when we may no longer rely mostly on fossil bricks. The transport of large quantities of fly fuel energy. ash and its eventual dumping are costs that have to be included in calculating the cost-benefits of thermal power. CASE STUDY The Exxon Valdez was wrecked in Prince Wil- liam Sound in Alaska in 1989 and polluted large parts of the surrounding seas. 38 Environmental Studies for Undergraduate Courses Chapter2.p65 38 4/9/2004, 5:07 PM

CASE STUDY CASE STUDY Nearly 50% of the world’s population is de- In 1882, the first Hydroelectric power dam pendent on fuel wood as a source of en- was built in Appleton, Wisconsin. In India the ergy. This is obvious in our own country, first hydroelectric power dams were built in which has lost a large proportion of its for- the late 1800s and early 1900s by the Tatas est cover as our population expands and in the Western Ghats of Maharashtra. burns enormous amounts of wood. Rural Jamshedjee Tata, a great visionary who de- women, and even women from the lower veloped industry in India in the 1800s, wished economic strata in towns, still have to spend to have a clean source of energy to run cot- a large part of their lives collecting fuel wood. ton and textile mills in Bombay as he found To overcome this, various types of fuel-effi- people were getting respiratory infections cient stoves (‘chulas’) can burn wood ex- due to coal driven mills. He thus asked the tremely slowly and do not waste the heat, British Government to permit him to develop and also produce less smoke and ash than dams in the Western Ghats to generate elec- normal ‘chulas’. There have also been sev- tricity. The four dams are the Andhra, eral efforts to grow fuelwood by involving Shirowata, Valvan and Mulshi hydel dams. local people in these efforts. Examples in- An important feature of the Tata power clude Social Forestry, Farm Forestry and Joint projects is that they use the high rainfall in Forestry Management. the hills as storage areas. While the rivers flowing eastwards from the Western Ghats Hydroelectric Power are dammed in the foothills near the Deccan plateau, the water is tunneled through the This uses water flowing down a natural gradi- crest of the Ghats to drop several hundred ent to turn turbines to generate electricity meters to the coastal belt. Large turbines in known as ‘hydroelectric power’ by constructing the power plants generate electricity for dams across rivers. Between 1950 and 1970, Mumbai and its giant industrial belt. Hydropower generation worldwide increased seven times. The long life of hydropower plants, the renew- able nature of the energy source, very low operating and maintenance costs, and absence of infla- tionary pressures as in fossil fuels, are some of its advan- tages. Natural Resources 39 Chapter2.p65 39 4/9/2004, 5:07 PM

Drawbacks: Although hydroelectric power has CASE STUDY led to economic progress around the world, it has created serious ecological problems. Narmada Project • To produce hydroelectric power, large ar- The Narmada Bachao Andolan in India is an eas of forest and agricultural lands are sub- example of a movement against large dams. merged. These lands traditionally provided The gigantic Narmada River Project has af- a livelihood for local tribal people and farm- fected the livelihoods of hundreds of ex- ers. Conflicts over land use are inevitable. tremely poor forest dwellers. The rich landholders downstream from the Sardar • Silting of the reservoirs (especially as a re- Sarovar dam will derive the maximum eco- sult of deforestation) reduces the life of the nomic benefit, whereas the poor tribal hydroelectric power installations. people have lost their homes and traditional way of life. The dam will also destroy the • Water is required for many other purposes livelihood of fishermen at the estuary. The besides power generation. These include disastrous impact that this project has on the domestic requirements, growing agricultural lives of the poor, and the way in which they crops and for industry. This gives rise to are being exploited, need to be clearly un- conflicts. derstood. • The use of rivers for navigation and fisher- With large dams causing social problems, there ies becomes difficult once the water is has been a trend to develop small hydroelectric dammed for generation of electricity. generation units. Multiple small dams have less impact on the environment. China has the larg- • Resettlement of displaced persons is a prob- est number of these - 60,000, generating 13,250 lem for which there is no ready solution. megawatts, i.e. 30% of China’s electricity. Swe- The opposition to many large hydroelectric den, the US, Italy and France also have devel- schemes is growing as most dam projects oped small dams for electrical power genera- have been unable to resettle people that tion. The development of small hydroelectric were affected and displaced. power units could become a very important re- source in India, which has steeply falling rivers • In certain regions large dams can induce and the economic capability and technical re- seismic activity which will result in earth- sources to exploit them. quakes. There is a great possibility of this occurring around the Tehri dam in the Hi- Solar energy: In one hour, the sun pours as malayan foothills. Shri Sunderlal Bahuguna, much energy onto the earth as we use in a whole the initiator of the Chipko Movement has year. If it were possible to harness this colossal fought against the Tehri Dam for several quantum of energy, humanity would need no years. other source of energy. Today we have devel- oped several methods of collecting this energy for heating water and generating electricity. 40 Environmental Studies for Undergraduate Courses Chapter2.p65 40 4/9/2004, 5:07 PM

Solar heating for homes: Modern housing that sorb the sun’s heat. The back and sides of the uses air conditioning and/ or heating are ex- box are insulated to hold in the heat. Heat builds tremely energy dependant. A passive solar home up in the collector, and as the fluid passes or building is designed to collect the sun’s heat through the tubes, it too heats up. through large, south-facing glass windows. In solar heated buildings, sunspaces are built on Solar water-heating systems cannot heat water the south side of the structure which act as large when the sun is not shining. Thus homes must heat absorbers. The floors of sunspaces are usu- also have a conventional backup system. About ally made of tiles or bricks that absorb heat 80% of homes in Israel have solar hot water throughout the day, then release heat at night heaters. when its cold. Solar cookers: The heat produced by the sun In energy efficient architecture the sun, water can be directly used for cooking using solar cook- and wind are used to heat a building when the ers. A solar cooker is a metal box which is black weather is cold and to cool it in summer. This is on the inside to absorb and retain heat. The lid based on design and building material. Thick has a reflective surface to reflect the heat from walls of stone or mud were used in traditional the sun into the box. The box contains black architecture as an insulator. Small doors and vessels in which the food to be cooked is placed. windows kept direct sunlight and heat out. Deeply set glass windows in colonial homes, on India has the world’s largest solar cooker pro- which direct sunlight could not reach, permit- gram and an estimated 2 lakh families that use ted the glass from creating a green house ef- solar cookers. Although solar cookers reduce the fect. Verandahs also served a similar purpose. need for fuel wood and pollution from smoky wood fires, they have not caught on well in ru- Traditional bungalows had high roofs and ven- ral areas as they are not suitable to traditional tilators that permitted hot air to rise and leave cooking practices. However, they have great the room. Cross ventilation where wind can drive potential if marketed well. the air in and out of a room keeps it cool. Large overhangs over windows prevent the glass from Other Solar-Powered Devices: Solar desalination heating the room inside. Double walls are used systems (for converting saline or brackish water to prevent heating. Shady trees around the into pure distilled water) have been developed. house help reduce temperature. In future, they should become important alter- natives for man’s future economic growth in Solar water heating: Most solar water-heating areas where fresh water is not available. systems have two main parts: the solar collec- tor and the storage tank. The solar energy col- Photovoltaic energy: The solar technology lector heats the water, which then flows to a which has the greatest potential for use through- well insulated storage tank. out the world is that of solar photo voltaic cells which directly produce electricity from sunlight A common type of collector is the flat-plate col- using photovoltaic (PV) (also called solar) cells. lector, a rectangular box with a transparent cover that faces the sun, usually mounted on Solar cells use the sun’s light, not its heat, to the roof. Small tubes run through the box, car- make electricity. PV cells require little mainte- rying the water or other fluid, such as antifreeze, nance, have no moving parts, and essentially to be heated. The tubes are mounted on a metal no environmental impact. They work cleanly, absorber plate, which is painted black to ab- 41 Natural Resources Chapter2.p65 41 4/9/2004, 5:07 PM

Photovoltaic Cells CASE STUDIES safely and silently. They can be installed quickly • In 1981, a plane called ‘The Solar Chal- in small modules, anywhere there is sunlight. lenger’ flew from Paris to England in 5 Solar cells are made up of two separate layers hours, 20 minutes. It had 16,000 solar of silicon, each of which contains an electric cells glued to the wings and tail of the charge. When light hits the cells, the charges plane and they produced enough power begin to move between the two layers and elec- to drive a small electric motor and pro- tricity is produced. PV cells are wired together peller. Since 1987, every three years to form a module. A module of about 40 cells is there is a World Solar challenge for so- enough to power a light bulb. For more power, lar operated vehicles in Australia where PV modules are wired together into an array. the vehicles cover 3000 kms. PV arrays can produce enough power to meet the electrical needs of a home. Over the past • The world’s first solar-powered hospital few years, extensive work has been done in is in Mali in Africa. Being situated at the decreasing PV technology costs, increasing effi- edge of the Sahara desert, Mali receives ciency, and extending cell lifetimes. Many new a large amount of sunlight. Panels of materials, such as amorphous silicon, are being solar cells supply the power needed to tested to reduce costs and automate manufac- run vital equipment and keep medical turing. supplies cool in refrigerators. • Space technology required solar energy and the space race spurred the devel- opment of solar cells. Only sunlight can provide power for long periods of time for a space station or long distance spaceship. PV cells are commonly used today in calculators • Japanese farmers are substituting PV op- and watches. They also provide power to satel- erated insect killers for toxic pesticides. lites, electric lights, and small electrical appli- ances such as radios and for water pumping, • In recent years, the popularity of build- highway lighting, weather stations, and other ing integrated photovoltaics (BIPV’s) has electrical systems located away from power lines. grown considerably. In this application, Some electric utility companies are building PV PV devices are designed as part of build- systems into their power supply networks. ing materials (i.e. roofs and siding) both to produce electricity and reduce costs PV cells are environmentally benign, ie. they do by replacing the costs of normal con- not release pollutants or toxic material to the struction materials. There are more than air or water, there is no radioactive substance, 3,000 BIPV systems in Germany and Ja- and no catastrophic accidents. Some PV cells, pan has a program that will build 70,000 however, do contain small quantities of toxic BIPV buildings. substances such as cadmium and these can be released to the environment in the event of a fire. Solar cells are made of silicon which, al- 42 Environmental Studies for Undergraduate Courses Chapter2.p65 42 4/9/2004, 5:07 PM

though the second most abundant element in Biomass energy: When a log is burned we are the earth’s crust, has to be mined. Mining cre- using biomass energy. Because plants and trees ates environmental problems. PV systems also depend on sunlight to grow, biomass energy is of course only work when the sun is shining, a form of stored solar energy. Although wood and thus need batteries to store the electricity. is the largest source of biomass energy, we also use agricultural waste, sugarcane wastes, and Solar thermal electric power: Solar radiation other farm byproducts to make energy. can produce high temperatures, which can gen- erate electricity. Areas with low cloud levels of There are three ways to use biomass. It can be cover with little scattered radiation as in the burned to produce heat and electricity, changed desert are considered most suitable sites. Ac- to a gas-like fuel such as methane, or changed cording to a UNDP assessment, STE is about 20 to a liquid fuel. Liquid fuels, also called biofuels, years behind the wind energy market exploita- include two forms of alcohol: ethanol and tion, but is expected to grow rapidly in the near methanol. Because biomass can be changed future. directly into liquid fuel, it could someday supply much of our transportation fuel needs for cars, Mirror energy: During the 1980s, a major solar trucks, buses, airplanes and trains with diesel thermal electrical generation unit was built in fuel replaced by ‘biodiesel’ made from vegetable California, containing 700 parabolic mirrors, oils. In the United States, this fuel is now being each with 24 reflectors, 1.5 meters in diameter, produced from soybean oil. Researchers are also which focused the sun’s energy to produce developing algae that produce oils, which can steam to generate electricity. be converted to biodiesel and new ways have been found to produce ethanol from grasses, trees, bark, sawdust, paper, and farming wastes. Mirror Energy Organic municipal solid waste includes paper, food wastes, and other organic non-fossil-fuel Solar thermal systems change sunlight into elec- derived materials such as textiles, natural rub- tricity, by focusing sunlight to boil water to make ber, and leather that are found in the waste of steam. urban areas. Currently, in the US, approximately 31% of organic waste is recovered from mu- Natural Resources nicipal solid waste via recycling and composting programs, 62% is deposited in landfills, and 7% is incinerated. Waste material can be converted into electricity by combustion boilers or steam turbines. Note that like any fuel, biomass creates some pollutants, including carbon dioxide, when burned or converted into energy. In terms of air pollutants, biomass generate less relative to fossil fuels. Biomass is naturally low in sulphur and therefore, when burned, generates low sulphur dioxide emissions. However, if burned in the open air, some biomass feedstocks would emit relatively high levels of nitrous oxides (given the 43 Chapter2.p65 43 4/9/2004, 5:07 PM

high nitrogen content of plan material), carbon Activity 5: monoxide, and particulates. What you may throw out in your garbage Biogas: Biogas is produced from plant material today could be used as fuel for someone and animal waste, garbage, waste from house- else. Municipal solid waste has the poten- holds and some types of industrial wastes, such tial to be a large energy source. Garbage is as fish processing, dairies, and sewage treatment an inexpensive energy resource. Unlike plants. It is a mixture of gases which includes most other energy resources, someone will methane, carbon dioxide, hydrogen sulphide collect garbage, deliver it to the power and water vapour. In this mixture, methane plant, and even pay to get rid of it. This burns easily. With a ton of food waste, one can helps cover the cost of turning garbage into produce 85 Cu. M of biogas. Once used, the energy. Garbage is also a unique resource residue is used as an agricultural fertilizer. because we all contribute to it. Denmark produces a large quantity of biogas Keep a record of all the garbage that you from waste and produces 15,000 megawatts and our family produce in a day. What pro- of electricity from 15 farmers’ cooperatives. Lon- portion of it is in the form of biomass? don has a plant which makes 30 megawatts of Weigh this. electricity a year from 420,000 tons of munici- pal waste which gives power to 50,000 fami- How long would it take you to gather lies. In Germany, 25% of landfills for garbage enough waste biomass to make a tankful produce power from biogas. Japan uses 85% (0.85 cu.m.) of biogas? (Remember one ton of its waste and France about 50%. of biomass produces 85 cu.m. of biogas) Biogas plants have become increasingly popu- Wind Power: Wind was the earliest energy lar in India in the rural sector. The biogas plants source used for transportation by sailing ships. use cowdung, which is converted into a gas Some 2000 years ago, windmills were developed which is used as a fuel. It is also used for run- ning dual fuel engines. The reduction in kitchen smoke by using biogas has reduced lung condi- tions in thousands of homes. The fibrous waste of the sugar industry is the in China, Afghanistan and Persia to draw water world’s largest potential source of biomass en- for irrigation and grinding grain. Most of the ergy. Ethanol produced from sugarcane molas- early work on generating electricity from wind ses is a good automobile fuel and is now used was carried out in Denmark, at the end of the in a third of the vehicles in Brazil. last century. Today, Denmark and California have large wind turbine cooperatives which sell The National Project on Biogas Development electricity to the government grid. In Tamil Nadu, (NPBD), and Community/ Institutional Biogas there are large wind farms producing 850 mega- Plant Program promote various biogas projects. watts of electricity. At present, India is the third By 1996 there were already 2.18 million fami- largest wind energy producer in the world. lies in India that used biogas. However China has 20 million households using biogas! 44 Environmental Studies for Undergraduate Courses Chapter2.p65 44 4/9/2004, 5:07 PM

The power in wind is a function of the wind electricity, and requires some other backup or speed and therefore the average wind speed of stand-by electricity source. an area is an important determinant of economi- cally feasible power. Wind speed increases with Tidal and Wave Power: The earth’s surface is height. At a given turbine site, the power avail- 70% water. By warming the water, the sun, able 30 meters above ground is typically 60 per- creates ocean currents and wind that produces cent greater than at 10 meters. waves. It is estimated that the solar energy ab- sorbed by the tropical oceans in a week could Over the past two decades, a great deal of tech- equal the entire oil reserves of the world – 1 nical progress has been made in the design, sit- trillion barrels of oil. The energy of waves in the ing, installation, operation, and maintenance of sea that crash on the land of all the continents power-producing wind mills (turbines). These im- is estimated at 2 to 3 million megawatts of en- provements have led to higher wind conversion ergy. From the 1970s several countries have efficiencies and lower electricity production been experimenting with technology to harness costs. the kinetic energy of the ocean to generate elec- tricity. Environmental Impacts: Wind power has few en- vironmental impacts, as there are virtually no Tidal power is tapped by placing a barrage across air or water emissions, or radiation, or solid an estuary and forcing the tidal flow to pass waste production. The principal problems are through turbines. In a one-way system the in- bird kills, noise, effect on TV reception, and aes- coming tide is allowed to fill the basin through thetic objections to the sheer number of wind a sluice, and the water so collected is used to turbines that are required to meet electricity produce electricity during the low tide. In a two- needs. way system power is generated from both the incoming as well as the outgoing tide. Although large areas of land are required for setting up wind farms, the amount used by the turbine bases, the foundations and the access roads is less than 1% of the total area covered by the wind farm. The rest of the area can also be used for agricultural purposes or for grazing. Siting windmills offshore re- duces their demand for land and visual impact. Wind is an intermittent 45 source and the intermittency of wind depends on the geo- graphic distribution of wind. Wind therefore cannot be used as the sole resource for Natural Resources Chapter2.p65 45 4/9/2004, 5:07 PM

Tidal power stations bring about major ecologi- Geo-Thermal cal changes in the sensitive ecosystem of coastal Energy regions and can destroy the habitats and nest- ing places of water birds and interfere with fish- deep below the surface of the earth to tap into eries. A tidal power station at the mouth of a geothermal reservoirs. This is called direct use river blocks the flow of polluted water into the of geothermal energy, and it provides a steady sea, thereby creating health and pollution haz- stream of hot water that is pumped to the ards in the estuary. Other drawbacks include earth’s surface. offshore energy devices posing navigational hazards. Residual drift current could affect In the 20th century geothermal energy has been spawning of some fish, whose larvae would be harnessed on a large scale for space heating, carried away from spawning grounds. They may industrial use and electricity production, espe- also affect the migration patterns of surface cially in Iceland, Japan and New Zealand. swimming fish. Geothermal energy is nearly as cheap as hydro- Wave power converts the motion of waves into power and will thus be increasingly utilised in electrical or mechanical energy. For this, an en- future. However, water from geothermal reser- ergy extraction device is used to drive turbo- voirs often contains minerals that are corrosive generators. Electricity can be generated at sea and polluting. Geothermal fluids are a problem and transmitted by cable to land. This energy which must be treated before disposal. source has yet to be fully explored. The largest concentration of potential wave energy on earth Nuclear Power is located between latitudes 40 to 60 degrees in both the northern and southern hemispheres, where the winds blow most strongly. Another developing concept harnesses energy due to the differences in temperature between the warm upper layers of the ocean and the cold deep sea water. These plants are known as Ocean Thermal Energy Conversion (OTEC). This is a high tech installation which may prove to be highly valuable in the future. Geothermal energy: is the energy stored In 1938 two German scientists Otto Hahn and within the earth (“geo” for earth and “ther- Fritz Strassman demonstrated nuclear fission. mal” for heat). Geothermal energy starts with They found they could split the nucleus of a ura- hot, molten rock (called magma) deep inside the nium atom by bombarding it with neutrons. As earth which surfaces at some parts of the earth’s the nucleus split, some mass was converted to crust. The heat rising from the magma warms energy. The nuclear power industry however underground pools of water known as geother- was born in the late 1950s. The first large-scale mal reservoirs. If there is an opening, hot un- nuclear power plant in the world became op- derground water comes to the surface and erational in 1957 in Pennsylvania, US. forms hot springs, or it may boil to form gey- sers. With modern technology, wells are drilled Dr. Homi Bhabha was the father of Nuclear Power development in India. The Bhabha Atomic 46 Environmental Studies for Undergraduate Courses Chapter2.p65 46 4/9/2004, 5:07 PM

Research Center in Mumbai studies and devel- and destroy an area for decades by its radioac- ops modern nuclear technology. India has 10 tivity which leads to death, cancer and genetic nuclear reactors at 5 nuclear power stations that deformities. Land, water, vegetation are de- produce 2% of India’s electricity. These are lo- stroyed for long periods of time. Management, cated in Maharashtra (Tarapur), Rajasthan, Tamil storage and disposal of radioactive wastes re- Nadu, Uttar Pradesh and Gujrat. India has ura- sulting from nuclear power generation are the nium from mines in Bihar. There are deposits of biggest expenses of the nuclear power indus- thorium in Kerala and Tamil Nadu. try. There have been nuclear accidents at Chernobyl in USSR and at the Three Mile Island The nuclear reactors use Uranium 235 to pro- in USA. The radioactivity unleashed by such an duce electricity. Energy released from 1kg of accident can affect mankind for generations. Uranium 235 is equivalent to that produced by burning 3,000 tons of coal. U235 is made into Energy Conservation: Conventional energy rods which are fitted into a nuclear reactor. The sources have a variety of impacts on nature and control rods absorb neutrons and thus adjust human society. the fission which releases energy due to the chain reaction in a reactor unit. The heat en- India needs to rapidly move into a policy to re- ergy produced in the reaction is used to heat duce energy needs and use cleaner energy pro- water and produce steam, which drives turbines duction technologies. A shift to alternate en- that produce electricity. The drawback is that ergy use and renewable energy sources that are the rods need to be changed periodically. This used judiciously and equitably would bring about has impacts on the environment due to disposal environmentally friendly and sustainable of nuclear waste. The reaction releases very hot lifestyles. India must reduce its dependency on waste water that damages aquatic ecosystems, imported oil. At present we are under-utilizing even though it is cooled by a water system be- our natural gas resources. We could develop fore it is released. thousands of mini dams to generate electricity. India wastes great amounts of electricity during The disposal of nuclear waste is becoming an transmission. Fuel wood plantations need to be increasingly serious issue. The cost of Nuclear enhanced and management through Joint For- Power generation must include the high cost of estry Management (JFM) has a great promise disposal of its waste and the decommissioning for the future. of old plants. These have high economic as well as ecological costs that are not taken into ac- Energy efficient cooking stoves or ‘chulas’ help count when developing new nuclear installa- the movement of air through it so that the wood tions. For environmental reasons, Sweden has is burnt more efficiently. They also have a chim- decided to become a Nuclear Free Country by ney to prevent air pollution and thus reduce res- 2010. piratory problems. While over 2 lakh improved chulas have been introduced throughout the Although the conventional environmental im- country, the number in active use is unknown pacts from nuclear power are negligible, what as most rural people find it to be unusable for overshadows all the other types of energy several reasons. TERI in 1995 estimated that in sources is that an accident can be devastating India 95% of rural people and 60% of urban and the effects last for long periods of time. poor still depend on firewood, cattle dung and While it does not pollute air or water routinely crop residue for cooking and other domestic like oil or biomass, a single accident can kill thou- purposes. Biomass can be converted into biogas sands of people, make many others seriously ill, 47 Natural Resources Chapter2.p65 47 4/9/2004, 5:07 PM

or liquid fuels ie. ethanol and methanol. Biogas CASE STUDIES digesters convert animal waste or agricultural residues into gas. This is 60% methane and 40% Indian industries use more energy than nec- CO2 generated by fermentation. The commonly essary. used agri waste is dung of domestic animals and rice husk, coconut shells, straw or weeds. The Steel and energy: To produce one tonne of material left after the gas is used acts as a fertil- steel, India spends 9.5 million kilocalories. In izer. Italy it is 4.3 million kilocalories and for Ja- pan it is only 4.1 million kilocalories. Small hydrogeneration units are environment- friendly. They do not displace people, destroy Cement industry: Over 2 million kilocalories forests or wildlife habitats or kill aquatic and are used to produce one tonne of cement in terrestrial biodiversity. They can be placed in India. In Germany it is 0.82 million kilocalo- several hill streams, on canals or rivers. The gen- ries, in USA, 0.92 million kilocalories. eration depends on flowing water due to grav- ity. However, this fails if the flow is seasonal. Vehicles: Lighter materials should be used for cars. Instead of steel we should use alu- It is easy to waste energy but cheaper to save it minum, fiber glass or plastics. These lighter than generate it. We can conserve energy by materials can reduce the weight by 15 % preventing or reducing waste of energy and by and increase the fuel economy by 6 to 8%. using resources more efficiently. People waste energy because government subsidises it. If the Refrigerators: Better technologies reduced real cost was levied, people would not be able the annual energy needed by a typical Dan- to afford to waste it carelessly. ish 200 liter refrigerator (with no freezer) from 350 kilo Watt hour (kWh) to 90 kWh. Industry and transport are the main grow- ing users of energy in India. Industries that Lighting: An 18-watt modern, compact fluo- are known for generating pollution also rescent lamp, can replace a standard 75-watt waste the most energy. These include chemi- incandescent lamp. cal industries, especially petrochemical units, iron and steel, textiles, paper, etc. Unplanned f) Land resources: and inefficient public transport systems, es- pecially in cities, waste large amount of en- Land as a resource: Landforms such as hills, ergy. Using bicycles is an excellent method valleys, plains, river basins and wetlands include to reduce the use of energy. In agriculture, different resource generating areas that the irrigation pumps to lift water are the most people living in them depend on. Many tradi- energy intensive agricultural use. These are tional farming societies had ways of preserving either electrical or run on fossil fuels. areas from which they used resources. Eg. In the ‘sacred groves’ of the Western Ghats, re- quests to the spirit of the Grove for permission to cut a tree, or extract a resource, were ac- companied by simple rituals. The outcome of a chance fall on one side or the other of a stone 48 Environmental Studies for Undergraduate Courses Chapter2.p65 48 4/9/2004, 5:07 PM

balanced on a rock gave Changes in land use or withheld permission. The request could not be repeated for a specified period. If land is utilized carefully it can be considered a renewable resource. The roots of trees and Land Degradation: Farmland is under threat grasses bind the soil. If due to more and more intense utilisation. Every forests are depleted, or year, between 5 to 7 million hectares of land grasslands overgrazed, worldwide is added to the existing degraded the land becomes un- farmland. When soil is used more intensively by productive and wasteland is formed. Intensive farming, it is eroded more rapidly by wind and irrigation leads to water logging and salination, rain. Over irrigating farmland leads to on which crops cannot grow. Land is also con- salinisation, as evaporation of water brings the verted into a non-renewable resource when salts to the surface of the soil on which crops highly toxic industrial and nuclear wastes are cannot grow. Over irrigation also creates water dumped on it. logging of the topsoil so that crop roots are af- fected and the crop deteriorates. The use of Land on earth is as finite as any of our other more and more chemical fertilizers poisons the natural resources. While mankind has learnt to soil so that eventually the land becomes unpro- adapt his lifestyle to various ecosystems world ductive. over, he cannot live comfortably for instance on polar ice caps, on under the sea, or in space in As urban centers grow and industrial expansion the foreseeable future. occurs, the agricultural land and forests shrink. This is a serious loss and has long term ill effects Man needs land for building homes, cultivating on human civilisation. food, maintaining pastures for domestic animals, developing industries to provide goods, and sup- porting the industry by creating towns and cit- ies. Equally importantly, man needs to protect wilderness area in forests, grasslands, wetlands, mountains, coasts, etc. to protect our vitally valuable biodiversity. Thus a rational use of land needs careful plan- Soil erosion: The characteristics of natural eco- ning. One can develop most of these different systems such as forests and grasslands depend types of land uses almost anywhere, but Pro- on the type of soil. Soils of various types sup- tected Areas (National Park’s and Wildlife Sanc- port a wide variety of crops. The misuse of an tuaries) can only be situated where some of the ecosystem leads to loss of valuable soil through natural ecosystems are still undisturbed. These erosion by the monsoon rains and, to a smaller Protected Areas are important aspects of good extent, by wind. The roots of the trees in the landuse planning. forest hold the soil. Deforestation thus leads to Natural Resources 49 Chapter2.p65 49 4/9/2004, 5:07 PM

rapid soil erosion. Soil is washed into streams 2.3 ROLE OF AN INDIVIDUAL IN CONSERVA- and is transported into rivers and finally lost to TION OF NATURAL RESOURCES the sea. The process is more evident in areas where deforestation has led to erosion on steep Until fairly recently mankind acted as if he could hill slopes as in the Himalayas and in the West- go on for ever exploiting the ecosystems and ern Ghats. These areas are called ‘ecologically natural resources such as soil, water, forests and sensitive areas’ or ESAs. To prevent the loss of grasslands on the Earth’s surface and extract- millions of tons of valuable soil every year, it is ing minerals and fossil fuels from underground. essential to preserve what remains of our natu- But, in the last few decades, it has become in- ral forest cover. It is equally important to refor- creasingly evident that the global ecosystem has est denuded areas. The linkage between the the capacity to sustain only a limited level of existence of forests and the presence of soil is utilization. Biological systems cannot go on re- greater than the forest’s physical soil binding plenishing resources if they are overused or mis- used. At a critical point, increasing pressure de- CASE STUDY stabilizes their natural balance. Even biological resources traditionally classified as ‘renewable’ Selenium – Punjab - such as those from our oceans, forests, grass- lands and wetlands, are being degraded by over- In 1981-82, farmers from Hoshirapur and use and may be permanently destroyed. And Nawanshehar Districts approached scientists no natural resource is limitless. ‘Non-renewable’ of the Punjab Agricultural University (PAU), resources will be rapidly exhausted if we con- Ludhiana, as wheat crops had turned white. tinue to use them as intensively as at present. Soil analysis indicated selenium (Se) levels in the area were above toxic limits. Se is a natu- The two most damaging factors leading to the rally occurring trace element, essential for current rapid depletion of all forms of natural animal and human health, but the gap be- resources are increasing ‘consumerism’ on the tween requirement and excess is narrow. part of the affluent sections of society, and rapid Soils containing 0.5 microgrammes (ug) of population growth. Both factors are the results Se per kg or more are injurious to health. In of choices we make as individuals. As individu- some areas of Punjab, Se levels ranges from als we need to decide; 0.31 ug/kg to 4.55ug/kg. Rice cultivation requires the presence of standing water. • What will we leave to our children? (Are Being highly soluble, Se dissolves and comes we thinking of short-term or long-term to the surface. The water then evaporates gain?) leaving the Se behind. • Is my material gain someone else’s loss? function alone. The soil is enriched by the leaf- litter of the forest. This detritus is broken down Greed for material goods has become a way of by soil micro-organisms, fungi, worms and in- life for a majority of people in the developed sects, which help to recycle nutrients in the sys- world. Population growth and the resulting tem. Further losses of our soil wealth will im- shortage of resources most severely affects poverish our country and reduce its capacity to people in the developing countries. In nations grow enough food in future. such as ours, which are both developing rap- idly, and suffering from a population explosion, both factors are responsible for environmental degradation. We must ask ourselves if we have 50 Environmental Studies for Undergraduate Courses Chapter2.p65 50 4/9/2004, 5:07 PM

perhaps reached a critical flash point, at which tional levels must be based on the ability to dis- economic ‘development’ affects the lives of tribute benefits of natural resources by sharing people more adversely than the benefits it pro- them more equally among the countries as well vides. as among communities within countries such as our own. It is at the local level where people What can you do to save electricity? subsist by the sale of locally collected resources, that the disparity is greatest. ‘Development’ has • Turn off lights and fans as soon as you leave not reached them and they are often unjustly the room. accused of ‘exploiting’ natural resources. They must be adequately compensated for the re- • Use tube lights and energy efficient bulbs moval of the sources to distant regions and thus that save energy rather than bulbs. A 40- develop a greater stake in protecting natural watt tube light gives as much light as a 100 resources. watt bulb. There are several principles that each of us can • Keep the bulbs and tubes clean. Dust on adopt to bring about sustainable lifestyles. This tubes and bulbs decreases lighting levels by primarily comes from caring for our Mother 20 to 30 percent. Earth in all respects. A love and respect for Na- ture is the greatest sentiment that helps bring • Switch off the television or radio as soon as about a feeling for looking at how we use natu- the program of interest is over. ral resources in a new and sensitive way. Think of the beauty of a wilderness, a natural forest • A pressure cooker can save up to 75 per- in all its magnificence, the expanse of a green cent of energy required for cooking. It is grassland, the clean water of a lake that sup- also faster. ports so much life, the crystal clear water of a hill stream, or the magnificent power of the • Keeping the vessel covered with a lid dur- oceans, and we cannot help but support the ing cooking, helps to cook faster, thus sav- conservation of nature’s wealth. If we respect ing energy. this we cannot commit acts that will deplete our life supporting systems. 2.4 EQUITABLE USE OF RESOURCES FOR 51 SUSTAINABLE LIFESTYLES Reduction of the unsustainable and unequal use of resources, and control of our population growth are essential for the survival of our na- tion and indeed of human kind everywhere. Our environment provides us with a variety of goods and services necessary for our day-to-day lives, but the soil, water, climate and solar energy which form the ‘abiotic’ support that we derive from nature, are in themselves not distributed evenly throughout the world or within countries. A new economic order at the global and at na- Natural Resources Chapter2.p65 51 4/9/2004, 5:07 PM

UNIT 3: Ecosystems 3.1 CONCEPT OF AN ECOSYSTEM 54 3.1.1 Understanding ecosystems 55 3.1.2 Ecosystem degradation 55 3.1.3 Resource utilisation 56 3.2 STRUCTURE AND FUNCTIONS OF AN ECOSYSTEM 56 3.3 PRODUCERS, CONSUMERS AND DECOMPOSERS 57 3.4 ENERGY FLOW IN THE ECOSYSTEM 58 3.4.1 The water cycle 58 3.4.2 The Carbon cycle 59 3.4.3 The Oxygen cycle 60 3.4.4 The Nitrogen cycle 60 3.4.5 The energy cycle 61 3.4.6 Integration of cycles in nature 62 3.5 ECOLOGICAL SUCCESSION 62 3.6 FOOD CHAINS, FOOD WEBS AND ECOLOGICAL PYRAMIDS 62 3.6.1 The food chains 62 3.6.2 The food webs 63 3.6.3 The ecological pyramids 63 3.7 INTRODUCTION, TYPES, CHARACTERISTIC FEATURES, STRUCTURE AND FUNCTIONS 63 3.7.1 Forest ecosystem 65 3.7.2 Grassland ecosystem 70 3.7.3 Desert ecosystem 74 3.7.4 Aquatic ecosystems (ponds, lakes, streams, rivers, estuaries, oceans) 75 Ecosystems 53 Chapter3.p65 53 4/9/2004, 5:08 PM

3.1 CONCEPT OF AN ECOSYSTEM the Western and Eastern Ghats, the semi-arid desert in the West, the Deccan Plateau, the An ‘Ecosystem’ is a region with a specific and Coastal Belts, and the Andaman and Nicobar recognizable landscape form such as forest, Islands. These geographically distinctive areas grassland, desert, wetland or coastal area. The have plants and animals that have been adapted nature of the ecosystem is based on its geo- to live in each of these regions. graphical features such as hills, mountains, plains, rivers, lakes, coastal areas or islands. It is At an even more local level, each area has sev- also controlled by climatic conditions such as the eral structurally and functionally identifiable eco- amount of sunlight, the temperature and the systems such as different types of forests, grass- rainfall in the region. The geographical, climatic lands, river catchments, mangrove swamps in and soil characteristics form its non-living (abi- deltas, seashores, islands, etc. to give only a few otic) component. These features create condi- examples. Here too each of these forms a habi- tions that support a community of plants and tat for specific plants and animals. animals that evolution has produced to live in these specific conditions. The living part of the Ecosystems have been formed on land and in ecosystem is referred to as its biotic component. the sea by evolution that has created species to live together in a specific region. Thus ecosys- Ecosystems are divided into terrestrial or land- tems have both non-living and living compo- based ecosystems, and aquatic ecosystems in nents that are typical to an area giving it its own water. These form the two major habitat condi- special characteristics that are easily observed. tions for the Earth’s living organisms. Definition: The living community of plants and All the living organisms in an area live in com- animals in any area together with the non-liv- munities of plants and animals. They interact ing components of the environment such as soil, with their non-living environment, and with each air and water, constitute the ecosystem. other at different points in time for a large num- ber of reasons. Life can exist only in a small pro- Some ecosystems are fairly robust and are less portion of the earth’s land, water and its atmo- affected by a certain level of human disturbance. sphere. At a global level the thin skin of the earth Others are highly fragile and are quickly de- on the land, the sea and the air, forms the bio- stroyed by human activities. Mountain ecosys- sphere. tems are extremely fragile as degradation of forest cover leads to severe erosion of soil and At a sub-global level, this is divided into bio- changes in river courses. Island ecosystems are geographical realms, eg. Eurasia called the easily affected by any form of human activity palaeartic realm; South and South-East Asia (of which can lead to the rapid extinction of sev- which India forms a major part) is the Oriental eral of their unique species of plants and ani- realm; North America is the Nearctic realm; mals. Evergreen forests and coral reefs are also South America forms the Neotropical realm; examples of species rich fragile ecosystems Africa the Ethiopian realm; and Australia the which must be protected against a variety of Australian realm. human activities that lead to their degradation. River and wetland ecosystems can be seriously At a national or state level, this forms biogeo- affected by pollution and changes in surround- graphic regions. There are several distinctive ing landuse. geographical regions in India- the Himalayas, the Gangetic Plains, the Highlands of Central India, 54 Environmental Studies for Undergraduate Courses Chapter3.p65 54 4/9/2004, 5:08 PM

3.1.1 Understanding ecosystems • ‘How does the ecosystem work’? The ecosystem functions through several Natural ecosystems include the forests, grass- biogeochemical cycles and energy transfer lands, deserts, and aquatic ecosystems such as mechanisms. Observe and document the ponds, rivers, lakes, and the sea. Man modified components of the ecosystem which con- ecosystems include agricultural land and urban sists of its non-living or abiotic features such or industrial land use patterns. as air, water, climate and soil. Its biotic com- ponents, the various plants and animals. Each ecosystem has a set of common features Both these aspects of the ecosystem inter- that can be observed in the field: act with each other through several func- tional aspects to form Nature’s ecosystems. • ‘What does the ecosystem look like?’ Plants, herbivores and carnivores can be One should be able to describe specific fea- seen to form food chains. All these chains tures of the different ecosystems in ones are joined together to form a ‘web of life’ own surroundings. Field observations must on which man depends. Each of these use be made in both urban and natural sur- energy that comes from the sun and pow- roundings. ers the ecosystem. • What is its structure? 3.1.2 Ecosystem degradation Is it a forest, a grassland, a water body, an agricultural area, a grazing area, an urban Ecosystems are the basis of life itself! The natu- area, an industrial area, etc.? ral ecosystems in the wilderness provide a vari- ety of products and are regions in which a num- What you should see are its different char- ber of vital ecological processes are present, acteristics. A forest has layers from the without which human civilization would not be ground to the canopy. A pond has differ- able to exist. ent types of vegetation from the periphery to its center. The vegetation on a mountain Ecosystems are however frequently disrupted by changes from its base to its summit. human actions which lead to the extinction of species of plants and animals that can live only • What is the composition of its plant and in the different natural ecosystems. Some spe- animal species? cies if eliminated seriously affect the ecosystem. List the well-known plants and animals you These are called ‘keystone’ species. Extinction can see. Document their abundance and occurs due to changes in land use. Forests are numbers in nature: very common, common, deforested for timber, wetlands are drained to uncommon, rare. Wild mammals will not create more agricultural land and semi arid be seen in large numbers, cattle would be grasslands that are used as pastures are changed common. Some birds are common – which into irrigated fields. Pollution from industry and are the most common species? Insect spe- waste from urban settings can also lead to ex- cies are very common and most abundant. tinction of several species. In fact there are so many that they cannot be easily counted. The reason for the depletion of natural resources is twofold – our rapidly exploding population Ecosystems that needs to sustain itself on resources, and the growth of affluent societies, which consume 55 Chapter3.p65 55 4/9/2004, 5:08 PM

and waste a very large proportion of resources The key to this issue is the need for an ‘equi- and energy. Increasing extraction of resources table’ distribution of all types of natural re- is at the cost of natural ecosystems, leading to a sources. A more even sharing of resources within derangement of their important functions. Each the community can reduce these pressures on of us in our daily lives use a variety of resources. the natural ecosystems. If tracked back to their source, one finds that the resources were originally obtained from 3.2 STRUCTURE AND FUNCTIONS OF AN nature and natural ecosystems. Our insensitiv- ECOSYSTEM ity to using resources carefully has produced societies that nature can no longer sustain. If Structural aspects one thinks before wasting resources such as wa- ter, reusing and recycling paper, using less plas- Components that make up the structural as- tics that are non-degradable, culminatively this pects of an ecosystem include: can have positive implications on the integrity of our natural resource base and conserve the 1) Inorganic aspects – C, N, CO2, H2O. resources that nature provides. 2) Organic compounds – Protein, Carbo- Ecosystems and man: Every region of our earth hydrates, Lipids – link abiotic to biotic has different ecosystems based on its climatic aspects. conditions and geographical feature. There are terrestrial ecosystems on land and aquatic eco- 3) Climatic regimes – Temperature, Mois- systems in water. ture, Light & Topography. 3.1.3 Resource utilisation 4) Producers – Plants. Most traditional societies used their environment 5) Macro consumers – Phagotrophs – Large sustainably. Though inequality in resource utili- animals. zation has existed in every society, the number of individuals that used a large proportion of 6) Micro consumers – Saprotrophs, absorb- resources was extremely limited. In recent times ers – fungi. the proportion of ‘rich’ people in affluent soci- eties, grew rapidly. Inequality thus became a se- Functional aspects rious problem. Whereas in the past many re- 1) Energy cycles. sources such as timber and fuel wood from the 2) Food chains. forest were extracted sustainably, this pattern 3) Diversity-interlinkages between organ- has drastically changed during the last century. The economically better off sections began to isms. use greater amounts of forest products, while 4) Nutrient cycles-biogeochemical cycles. those people who lived in the forest became 5) Evolution. increasingly poor. Similarly the building of large irrigation projects led to wealth in those areas that had canals, while those who hand to re- main dependent on a constant supply of water from the river itself, found it difficult to survive. 56 Environmental Studies for Undergraduate Courses Chapter3.p65 56 4/9/2004, 5:08 PM

Since each ecosystem has a non-living and a liv- Plants are the ‘producers’ in the ecosystem as ing part that are linked to each other, one needs they manufacture their food by using energy to look around us and observe this closely. This from the sun. In the forest these form commu- is an important aspect that is a vital part of our nities of plant life. In the sea these include tiny lives. algal forms to large seaweed. The non-living components of an ecosystem are The herbivorous animals are primary consum- the amount of water, the various inorganic sub- ers as they live on the producers. In a forest, stances and organic compounds, and climatic these are the insects, amphibia, reptiles, birds conditions such as rainfall and temperature, and mammals. The herbivorous animals include which depend on geographical conditions and for example hare, deer and elephants that live location which is also related to the amount of on plant life. They graze on grass or feed on the sunlight. The living organisms in an ecosystem foliage from trees. In grasslands, there are her- are inseparable from their habitat. bivores such as the blackbuck that feed on grass. In the semiarid areas, there are species such as The living component of plant life ranges from the chinkara or Indian gazelle. In the sea, there extremely small bacteria, which live in air, wa- ter and soil, algae which live in fresh and salt Herbivores water, to the terrestrial plants which range from grasses and herbs that grow after the monsoon Nectarivores every year, to the giant long-lived trees of the forest. The plants convert energy from sunlight Frugivores into organic matter for their growth. They thus function as producers in the ecosystem. The liv- ing component of the animal world ranges from microscopic animals, to small insects and the larger animals such as fish, amphibia, reptiles, birds and mammals. Man is just one of the 1.8 million species of plants and animals that inhabit the earth. 3.3 PRODUCERS, CONSUMERS AND DECOM- Gramnivores POSERS Every living organism is in some way dependent are small fish that live on algae and other plants. on other organisms. Plants Grass At a higher tropic level, there are carnivorous are food for herbivorous ani- animals, or secondary consumers, which live mals which are in turn food on herbivorous ani- mals. In our forests, for carnivorous animals. the carnivorous ani- mals are tigers, leop- Thus there are different ards, jackals, foxes and small wild cats. In Carnivores tropic levels in the ecosys- 57 tem. Some organisms such as fungi live only on dead material and inorganic mat- ter. Ecosystems Chapter3.p65 57 4/9/2004, 5:08 PM

the sea, carnivorous fish live on other fish and is not widely distributed, it becomes extinct for marine animals. Animals that live in the sea all time. range in size from microscopic forms to giant mammals such as the whale. 3.4 ENERGY FLOW IN THE ECOSYSTEM Decomposers or detrivores are a group of or- Every ecosystem has several interrelated mecha- ganisms consisting of small animals like worms, nisms that affect human life. These are the wa- insects, bacteria and fungi, which break down ter cycle, the carbon cycle, the oxygen cycle, dead organic material into smaller particles and the nitrogen cycle and the energy cycle. While finally into simpler substances that are used by every ecosystem is controlled by these cycles, in plants as nutrition. Decomposition thus is a vital each ecosystem its abiotic and biotic features function in nature, as without this, all the nutri- are distinct from each other. ents would be tied up in dead matter and no new life could be produced. All the functions of the ecosystem are in some way related to the growth and regeneration of Most ecosystems are highly complex and con- its plant and animal species. These linked pro- sist of an extremely large number of individuals cesses can be depicted as the vari- Detrivores ous cycles. These processes de- pend on energy from sunlight. of a wide variety of species. In the species-rich During photosynthesis carbon di- tropical ecosystems (such as in our country), only oxide is taken up by plants and a few species are very common, while most spe- oxygen is released. Animals de- cies have relatively few individuals. Some spe- pend on this oxygen for their res- cies of plants and animals are extremely rare piration. The water cycle depends and may occur only at a few locations. These on the rainfall, which is necessary are said to be ‘endemic’ to these areas. for plants and animals to live. The energy cycle recycles nutrients When human activities alter the balance in these into the soil on which plant life ecosystems, the “perturbation” leads to the grows. Our own lives are closely disappearance of these uncommon species. linked to the proper functioning When this happens to an endemic species that of these cycles of life. If human activities go on altering them, humanity cannot survive on our earth. 3.4.1 The Water Cycle When it rains, the water runs along the ground and flows into rivers or falls directly into the sea. A part of the rainwater that falls on land perco- lates into the ground. This is stored underground throughout the rest of the year. Water is drawn up from the ground by plants along with the nutrients from the soil. The water is transpired from the leaves as water vapour and returned 58 Environmental Studies for Undergraduate Courses Chapter3.p65 58 4/9/2004, 5:08 PM

Water Cycle 3.4.2 The Carbon cycle to the atmosphere. As it is lighter than air, wa- The carbon, which occurs in ter vapour rises and forms clouds. Winds blow organic compounds, is in- the clouds for long distances and when the cluded in both the abiotic and clouds rise higher, the vapour condenses and biotic parts of the ecosystem. changes into droplets, which fall on the land as Carbon is a building block of rain. Though this is an end- both plant and animal tissues. less cycle on which life de- In the atmosphere, carbon pends, man’s activities are occurs as carbon dioxide making drastic changes in (CO2). In the presence of sun- the atmosphere through light, plants take up carbon pollution which is altering dioxide from the atmosphere rainfall patterns. This is through their leaves. The leading to prolonged plants combine carbon diox- drought periods extending ide with water, which is ab- over years in countries sorbed by their roots from the such as Africa, while caus- soil. In the presence of sun- ing floods in countries such light they are able to form car- as the US. El Nino storms bohydrates that contain car- due to these effects have bon. This process is known as devastated many places in photosynthesis. Plants use this the last few years. complex mechanism for their Ecosystems growth and development. In this process, plants release oxygen into the atmosphere on which animals depend for their respiration. Plants therefore help in regulating and monitoring the percent- age of Oxygen and Carbon dioxide in the earth’s atmosphere. All of mankind thus depends on Carbon Cycle 59 Chapter3.p65 59 4/9/2004, 5:08 PM

the oxygen generated through this cycle. It also 3.4.4 The Nitrogen Cycle keeps the CO2 at acceptable levels. Carnivorous animals feed on herbivorous ani- Herbivorous animals feed on plant material, mals that live on plants. When animals defecate, which is used by them for energy and for their this waste material is broken down by worms growth. Both plants and animals release carbon and insects mostly beetles and ants. These small dioxide during respiration. They also return fixed ‘soil animals’ break the waste material into carbon to the soil in the waste they excrete. smaller bits on which microscopic bacteria and When plants and animals die they return their fungi can act. This material is thus broken down carbon to the soil. These processes complete the further into nutrients that plants can absorb and carbon cycle. use for their growth. Thus nutrients are recycled back from animals to plants. Similarly the bod- Oxygen Cycle > ies of dead animals are also broken down into nutrients that are used by the plants for their growth. Thus the nitrogen cycle on which life is dependent is com- pleted. > Nitrogen fixing bacteria and > > fungi in soil gives this impor- > 3.4.3 The Oxygen Cycle tant element to plants, which absorb it as nitrates. The ni- Oxygen is taken up by plants and ani- trates are a part of the plant’s mals from the air during respiration. metabolism, which help in The plants return oxygen to the at- forming new plant proteins. mosphere during photosynthesis. This This is used by animals that links the Oxygen Cycle to the Carbon feed on the plants. The nitro- Cycle. Deforestation is likely to gradu- gen is then transferred to car- ally reduce the oxygen levels in our nivorous animals when they atmosphere. Thus plant life plays an feed on the herbivores. Thus our own lives are important role in our lives which we frequently do not appreciate. This is > an important reason to participate in afforestation programs. Nitrogen Cycle > > 60 Environmental Studies for Undergraduate Courses Chapter3.p65 60 4/9/2004, 5:08 PM

closely interlinked to soil animals, fungi and even Since plants can grow by converting the sun’s bacteria in the soil. When we think of food webs, energy directly into their tissues, they are known we usually think of the large mammals and other as producers in the ecosystem. The plants are large forms of life. But we need to understand used by herbivorous animals as food, which that it is the unseen small animals, plants and gives them energy. A large part of this energy is microscopic forms of life that are of great value used up for day to day functions of these ani- for the functioning of the ecosystem. mals such as breathing, digesting food, support- ing growth of tissues, maintaining blood flow 3.4.5 The Energy Cycle and body temperature. Energy is also used for activities such as looking for food, finding shel- The energy cycle is based on the flow of energy ter, breeding and bringing up young ones. The through the ecosystem. Energy from sunlight is carnivores in turn depend on herbivorous ani- converted by plants themselves into growing mals on which they feed. Thus the different plant new plant material which includes leaves, flow- and animal species are linked to one another ers, fruit, branches, trunks and roots of plants. through food chains. Each food chain has three or four links. However as each plant or animal can be linked to several other plants or animals through many different link- ages, these inter-linked chains can be depicted as a complex food web. This is thus called the ‘web of life’ that shows that there are thousands of interrelation- ships in nature. The energy in the ecosystem can be de- picted in the form of a food pyramid or energy pyramid. The food pyramid has a large base of plants called ‘produc- ers’. The pyramid has a narrower middle section that depicts the number and bio- mass of herbivorous animals, which are called ‘first order consumers’. The apex depicts the small biomass of carnivorous animals called ‘second order consum- ers’. Man is one of the animals at the apex of the pyramid. Thus to support mankind, there must be a large base of herbivorous animals and an even greater quantity of plant material. Energy Cycle When plants and animals die, this ma- Ecosystems terial is returned to the soil after being broken down into simpler substances by decomposers such as insects, worms, bacteria and fungi so that plants can absorb the nutrients through their roots. 61 Chapter3.p65 61 4/9/2004, 5:08 PM

Animals excrete waste products after digesting related to the way in which energy flows food, which goes back to the soil. This links the through the biological system. The most fre- energy cycle to the Nitrogen cycle. quent example of successional changes occur in a pond ecosystem where it fluctuates from a 3.4.6 Integration of cycles in Nature dry terrestrial habitat to the early colonisation stage by small aquatic species after the mon- These cycles are a part of global life processes. soon, which gradually passes through to a ma- These biogeochcemical cycles have specific fea- ture aquatic ecosystem, and then reverts back tures in each of the ecosystems. These cycles to its dry stage in summer where its aquatic life are however linked to those of adjacent ecosys- remains dormant. tems. Their characteristics are specific to the plant and animal communities in the region. This 3.6 FOOD CHAINS, FOOD WEBS AND ECO- is related to the geographical features of the LOGICAL PYRAMIDS area, the climate and the chemical composition of the soil. Together the cycles are responsible The transfer of energy from the source in plants for maintaining life on earth. If mankind disturbs through a series of organisms by eating and these cycles beyond the limits that nature can being eaten constitutes food chains. At each sustain, they will eventually break down and lead transfer, a large proportion of energy is lost in to a degraded earth on which man will not be the form of heat. These food chains are not iso- able to survive. lated sequences, but are interconnected with each other. This interlocking pattern is known 3.5 ECOLOGICAL SUCCESSION as the food web. Each step of the food web is called a trophic level. Hence green plants oc- Ecological succession is a process through which cupy the first level, herbivores the second level, ecosystems tend to change over a period of time. carnivores the third level and secondary carni- Succession can be related to seasonal environ- vores the fourth level. These trophic levels to- mental changes, which create changes in the gether form the ecological pyramid. community of plants and animals living in the ecosystem. Other successional events may take 3.6.1 The food chains much longer periods of time extending to sev- eral decades. If a forest is cleared, it is initially The most obvious aspect of nature is that en- colonized by a certain group of species of plants ergy must pass from one living organism to an- and animals, which gradually change through other. When herbivorous animals feed on plants, an orderly process of community development. energy is transferred from plants to animals. In One can predict that an opened up area will an ecosystem, some of the animals feed on other gradually be converted into a grassland, a living organisms, while some feed on dead or- shrubland and finally a woodland and a forest if ganic matter. The latter form the ‘detritus’ food permitted to do so without human interference. chain. At each linkage in the chain, a major part There is a tendency for succession to produce a of the energy from the food is lost for daily ac- more or less stable state at the end of the suc- tivities. Each chain usually has only four to five cessional stages. Developmental stages in the such links. However a single species may be ecosystem thus consist of a pioneer stage, a linked to a large number of species. series of changes known as serel stages, and finally a climax stage. The successive stages are 62 Environmental Studies for Undergraduate Courses Chapter3.p65 62 4/9/2004, 5:08 PM

3.6.2 The food webs Aquatic Food Pyramid In an ecosystem there are a very large number of interlinked chains. This forms a food web. If the linkages in the chains that make up the web of life are disrupted due to human activities that lead to the loss or extinction of species, the web breaks down. 3.6.3 The ecological pyramids In an ecosystem, green plants – the producers, utilize energy directly from sunlight and convert it into matter. A large number of these organ- isms form the most basic, or first ‘trophic level’ of the food pyramid. The herbivorous animals that eat plants are at the second trophic level Terrestrial and are called primary consumers. The preda- Food Pyramid tors that feed on them form the third trophic level and are known as secondary consumers. Ecosystems Only a few animals form the third trophic level consisting of carnivores at the apex of the food pyramid. This is how energy is used by living creatures and flows through the ecosystem from its base to the apex. Much of the energy is used up in activities of each living organism. 3.7 INTRODUCTION, TYPES, CHARACTERIS- TIC FEATURES, STRUCTURE AND FUNCTIONS Types of Ecosystems Terrestrial Ecosystems Aquatic Ecosystems Forest Pond Grassland Lake Semi arid areas Wetland Deserts River Mountains Delta Islands Marine 63 Chapter3.p65 63 4/9/2004, 5:08 PM

For each of these ecosystems we need to un- • Existence value - ethical and emotional derstand 4 basic issues: aspects of the existence of wildlife and nature. 1. What is the nature of the ecosystem? What is its structure and its functions? Terrestrial ecosystems in their natural state are found in different types of forests, grasslands, 2. Who uses the ecosystem and for what pur- semiarid areas, deserts and sea coasts. Where pose? the land is intensively used, these have been gradually modified over several thousand years 3. How are these ecosystems degraded? into agricultural and pastoral regions. In the re- cent past they have been rapidly converted into 4. What can be done to protect it from deterio- intensively irrigated agricultural ecosystems or rating in the long-term? How can the ecosys- into urban and industrial centers. Though this tem be conserved? has increased production of food and pro- vides the raw material for ‘consumer’ goods Ecosystem goods and services that we use, the overuse and misuse of land and natural ecosystems has led to a serious Direct Values: degradation of our environment. The unsus- These are resources that people depend upon tainable use of environmental goods such as soil, directly and are easy to quantify in economic water, fuelwood, timber from forest, grasses terms. and herbs from grasslands for grazing and re- peatedly burning the grass, degrades these natu- • Consumptive Use Value - Non-market ral ecosystems. Similarly, improper use of re- value of fruit, fodder, firewood, etc. sources can destroy the services that the natu- that are used by people who collect ral ecosystems provide. These processes of na- them from their surrounds.] ture such as photosynthesis, climate control, pre- vention of soil erosion are disturbed by many • Productive Use Value - Commercial human activities. When our human population value of timber, fish, medicinal plants, was small, most ecosystems could supply all our etc. that people collect for sale. needs. Resources were thus used ‘sustainably’. As industrial ‘development’ led to a very great Indirect Values: increase in consumption of resources, the short These are uses that do not have easy ways to term economic gains for people became an in- quantify them in terms of a clearly definable dicator of progress, rather than long term eco- price. logical benefits. This has resulted in an ‘unsus- tainable use’ of natural resources. Forests thus • Non-consumptive use value - scientific disappear, rivers run dry, deserts begin to spread, research, bird-watching, ecotourism, and air, water and soil become increasingly pol- etc. luted as by-products of development. Human well being itself is then seriously affected. • Option value - maintaining options for the future, so that by preserving them one could reap economic benefits in the future. 64 Environmental Studies for Undergraduate Courses Chapter3.p65 64 4/9/2004, 5:08 PM

3.7.1 Forest ecosystem The biotic component includes both the large (macrophytes) and the microscopic plants and Forests are formed by a community of plants animals. which is predominantly structurally defined by its trees, shrubs, climbers and ground cover. Plants include the trees, shrubs, climbers, Natural vegetation looks vastly different from a grasses, and herbs in the forest. These include group of planted trees, which are in orderly species that flower (angiosperms), and non-flow- rows. The most ‘natural’ undisturbed forests are ering species (gymnosperms) such as ferns, bryo- located mainly in our National Parks and Wild- phytes, fungi and algae. life Sanctuaries. The landscapes that make up various types of forests look very different from The animals include species of mammals, birds, each other. Their distinctive appearance is a fas- reptiles, amphibians, fish, insects and other in- cinating aspect of nature. Each forest type forms vertebrates and a variety of microscopic animals. a habitat for a specific community of animals that are adapted to live in it. As the plant and animal species are closely de- pendent on each other, together they form dif- What is a forest ecosystem? ferent types of forest communities. Man is a part The forest ecosystem has two parts: of these forest ecosystems and the local people depend directly on the forest for several natural • The non-living or abiotic aspects of the resources that act as their life support systems. forest: The type of forest depends upon the People who do not live in the forest buy forest abiotic conditions at the site. Forests on products such as wood and paper, which has mountains and hills differ from those along been extracted from the forest. Thus they use river valleys. Vegetation is specific to the forest produce indirectly from the market. amount of rainfall and the local tempera- ture which varies according to latitude and Forest types in India: The forest type depends altitude. Forests also vary in their plant com- upon the abiotic factors such as climate and soil munities in response to the type of soil. characteristics of a region. Forests in India can be broadly divided into Coniferous forests and • The living or the biotic aspects of the for- Broadleaved forests. est: The plants and animals form commu- nities that are specific to each forest type. They can also be classified according to the na- For instance coniferous trees occur in the ture of their tree species – evergreen, decidu- Himalayas. Mangrove trees occur in river ous, xerophytic or thorn trees, mangroves, etc. deltas. Thorn trees grow in arid areas. The They can also be classified according to the most snow leopard lives in the Himalayas while abundant species of trees such as Sal or Teak the leopard and tiger live in the forests of forests. In many cases a forest is named after the rest of India. Wild sheep and goats live the first three or four most abundant tree spe- high up in the Himalayas. Many of the birds cies. of the Himalayan forests are different from the rest of India. Evergreen forests of the Coniferous forests grow in the Himalayan moun- Western Ghats and North East India are tain region, where the temperatures are low. most rich in plant and animal species. These forests have tall stately trees with needle- like leaves and downward sloping branches so that the snow can slip off the branches. They Ecosystems 65 Chapter3.p65 65 4/9/2004, 5:08 PM

Coniferous forest eral months. Some even get two monsoons, such as in Southern In- dia. Evergreen plants shed a few of their leaves throughout the year. There is no dry leafless phase as in a deciduous forest. An evergreen for- est thus looks green throughout the year. The trees overlap with each other to form a continuous canopy. Thus very little light penetrates down to the forest floor. Only a few shade loving plants can grow in the ground layer in areas where some light fil- ters down from the closed canopy. The forest is rich in orchids and ferns. The barks of the trees are covered in moss. The forest abounds in ani- mal life and is most rich in insect life. Evergreen forest Broadleaved forest have cones instead of seeds and are Environmental Studies for Undergraduate Courses called gymnosperms. Broadleaved forests have several types, such as evergreen forests, deciduous forests, thorn forests, and mangrove forests. Broadleaved forests have large leaves of various shapes. Evergreen forests grow in the high rain- fall areas of the Western Ghats, North Eastern India and the Andaman and Nicobar Islands. These forests grow in areas where the monsoon lasts for sev- 66 Chapter3.p65 66 4/9/2004, 5:08 PM

Deciduous forest Thorn forest Deciduous forests are found in regions called xerophytic species and are with a moderate amount of seasonal able to conserve water. Some of rainfall that lasts for only a few months. these trees have small leaves, Most of the forests in which Teak trees while other species have thick, grow are of this type. The deciduous waxy leaves to reduce water trees shed their leaves during the win- losses during transpiration. Thorn ter and hot summer months. In March forest trees have long or fibrous or April they regain their fresh leaves just roots to reach water at great before the monsoon, when they grow depths. Many of these plants vigorously in response to the rains. Thus have thorns, which reduce wa- there are periods of leaf fall and canopy ter loss and protect them from regrowth. The forest frequently has a herbivores. thick undergrowth as light can penetrate easily onto the forest floor. Mangrove forests grow along the coast especially in the river del- Thorn forests are found in the semi- arid tas. These plants are able to grow regions of India. The trees, which are sparsely distributed, are surrounded by Mangrove open grassy areas. Thorny plants are 67 Ecosystems Chapter3.p65 67 4/9/2004, 5:08 PM

Forest communities: Forest type Plants Examples Common Animal Examples Rare Animal Examples Himalayan Coniferous Pine, deodar Wild goats and sheep, Snow leopard, Hangul, Himalayan black bear. Himalayan brown bear, Himalayan Broadleaved Maple, oak Musk deer, Himalayan Tiger, Leopard, Sambar, Malabar Wolf. Evergreen North-east, Jamun, Ficus, whistling thrush, Malabar Pied Western Ghats, Dipterocarpus hornbill, tree frogs. Pigmy Hog, Rhino, Andaman & Nicobar Liontailed macaque Deciduous – Dry Teak, Ain, Terminalia Tiger, Chital, Barking deer, Babblers, Flycatchers, Hornbills. Moist Sal Blackbuck, Chinkara, Fourhorned Wolf, Bustard, Florican, Babul, Ber, Neem antelope, Partridge, Monitor Bustards, Thorn and scrub, lizard. Semiarid forests Mangrove Delta Avicenia Crocodile, shorebirds – sandpipers, Water monitor lizard. Forests plovers, fish, crustacea. in a mix of saline and fresh water. They grow During the monsoon, the forest retains mois- luxuriantly in muddy areas covered with silt that ture and slowly releases it through perennial the rivers have brought down. The mangrove streams during the rest of the year. Plantations trees have breathing roots that emerge from fail to perform this function adequately. The loss the mudbanks. of forest cover in the catchments of a river thus leads to irreversible changes such as excessive Forest utilisation: Natural forests provide local soil erosion, large run-off of surface water dur- people with a variety of products if the forest is ing monsoons leading to flash floods, and a used carefully. Over-exploitation for fuel wood shortage of water once the monsoons are over. or timber, and conversion to monoculture plan- tations for timber or other products, impover- Forest products that are collected by people ishes local people as the economic benefit goes include food such as fruit, roots, herbs and me- to people who live elsewhere. The entire re- dicinal plants. People depend on fuelwood to source base on which local people have tradi- cook food, collect fodder for domestic animals, tionally survived for generations, is rapidly de- cut building material for housing, collect stroyed. Eventually the forest is completely de- medicinal plants that have been known for graded. generations for several ailments and use a vari- ety of non timer forest products such as fiber, Natural forest ecosystems play an important role cane, gum, to make household articles. Wood in controlling local climate and water regimes. from different species of trees have special uses. It is well-known that under the canopy of a natu- For instance a soft wood is used for the yok of a ral forest, it is cooler than outside the forest. bullock cart while a very hard wood is used for its axil. These forest products are of great eco- 68 Environmental Studies for Undergraduate Courses Chapter3.p65 68 4/9/2004, 5:08 PM

Forest Products are more resistant to diseases. New industrial products are being produced from the wild plants of the forest. Many of our new medi- cines come from wild plants. nomic value as they are collected, sold and mar- Direct uses of forest products keted. Forest dwellers and agricultural people Fruits – mango, jamun, awla use these goods directly. Other people get them Roots – Dioscoria indirectly from the market. Traditional types of Medicine – Gloriosa, Foxglove agriculture needs forest material such as Fuelwood – many species of trees and shrubs branches and leaves, which are burnt to form Small timber for building huts and houses wood ash which acts as a fertiliser for crops such Wood for farm implements as rice. Bamboo and cane for baskets Grass for grazing and stall feeding livestock Urban people use these forest resources indi- rectly as all their food and other goods come Indirect uses of forest products from agricultural areas that are dependent on Building material for construction and furni- the neighbouring forests. ture for the urban sector Medicinal products collected and processed Forest services include the control of the flow into drugs of water in streams and rivers. Forest cover re- Gums and resins processed into a variety of duces surface runoff of rainwater and allows products ground water to be stored. Forests prevent ero- Raw material for industrial products and sion of soil. Once soil is lost by erosion, it can chemicals take thousands of years to reform. Forests regu- Paper from bamboo and softwoods late local temperature. It is cooler and more moist under the shade of the trees in the forest. What are the threats to the forest ecosys- Most importantly, forests absorb carbon diox- tem? ide and release oxygen that we breathe. As forests grow very slowly, we cannot use more resources than they can produce during a grow- The wild relatives of our crop plants and fruit ing season. If timber is felled beyond a certain trees have special characteristics in their genes limit the forest cannot regenerate. The gaps in which are used to develop new crops and newer the forest change the habitat quality for its ani- varieties of fruit. These newer varieties devel- mals. The more sensitive species cannot survive oped from wild relatives give greater yields or under these changed conditions. Overutilizing Ecosystems 69 Chapter3.p65 69 4/9/2004, 5:08 PM

forest resources is an unsustainable way of mis- linate agricultural crops and fruit trees. This leads using our limited forest resources. We are now to a decrease in agricultural yields. creating more and more goods that are manu- factured from raw material from the forest. This The rain that falls on deforested land flows di- leads to forest degradation and finally changes rectly into nearby rivers. Thus water is not re- the ecosystem into wasteland. Wood is illegally tained under the ground. People thus do not extracted from many forests leading to a highly get a sufficient quantity of water throughout disturbed ecosystem. the year. The exposed soil is rapidly washed away during the rains once the protective forest cover Developmental activities such as rapid popula- is removed. Thus agriculture is seriously affected tion growth together with, urbanisation, in such areas. In deforested areas, the water in industrialisation and the increasing use of con- streams is brown in colour as soil is washed away sumer goods, leads to over utilisation of forest while water in forested streams is crystal clear. produce. Forests are shrinking as our need for agricultural land increases. It is estimated that Wild animals lose their habitat. This leads to India’s forest cover has decreased from about extinction of our precious species. Residual for- 33% to 11% in the last century. The increasing ests must be protected from being destroyed use of wood for timber, wood pulp for paper any further if all the diverse species of plants and the extensive use of fuelwood results in and animals are to be kept for future genera- continual forest loss. Forests are also lost by tions. mining and building dams. As the forest re- sources are exploited beyond what they can pro- How can forest ecosystems be conserved? duce the forest canopy is opened up, the eco- We can conserve forests only if we use its re- system is degraded, and its wildlife is seriously sources carefully. This can be done by using al- threatened. As the forest is fragmented into ternate sources of energy instead of fuelwood. small patches its wild plant and animal species There is a need to grow more trees than are cut become extinct. These can never be brought down from forests every year for timber. Affor- back. Extinction is forever. estation needs to be done continuously from which fuelwood and timber can be judiciously What if the forests disappear? used. When forests are cut down tribal people who depend directly on them for food and fuelwood The natural forests with all their diverse species and other products find it very difficult to sur- must be protected as National Parks and Wild- vive. Agricultural people do not get enough life Sanctuaries where all the plants and animals fuelwood, small timber, etc. for making houses can be preserved. and farm implements. Urban people who de- pend on food from agricultural areas, which in 3.7.2 Grassland ecosystems turn depend on neighbouring forest ecosystems have to pay a higher price for food as human A wide range of landscapes in which the veg- population grows. etation is mainly formed by grasses and small annual plants are adapted to India’s various cli- Insects that live and breed in the forest such as matic conditions. These form a variety of grass- bees, butterflies and moths decrease in abun- land ecosystems with their specific plants and dance once forests are degraded. As their num- animals. bers decrease they are unable to effectively pol- 70 Environmental Studies for Undergraduate Courses Chapter3.p65 70 4/9/2004, 5:08 PM

What is a grassland ecosystem? Himalayan Pastures Grasslands cover areas where rainfall is usually low and/or the soil depth and quality is poor. into the high altitude grasslands in summer and The low rainfall prevents the growth of a large move down into the forest in winter when the number of trees and shrubs, but is sufficient to snow covers the grassland. These Himalayan support the growth of grass cover during the pastures have a large variety of grasses and monsoon. Many of the grasses and other small herbs. Himalayan hill slopes are covered with herbs become dry and the part above the thousands of colourful flowering plants. There ground dies during the summer months. In the are also a large number of medicinal plants. next monsoon the grass cover grows back from the root stock and the seeds of the previous The Terai consists of patches of tall grasslands year. This change gives grasslands a highly sea- interspersed with a Sal forest ecosystem. The sonal appearance with periods of increased patches of tall elephant grass, which grows to a growth followed by a dormant phase. height of about five meters, are located in the low-lying waterlogged areas. The Sal forest A variety of grasses, herbs, and several species patches cover the elevated regions and the Hi- of insects, birds and mammals have evolved so malayan foothills. The Terai also includes that they are adapted to these wide-open grass marshes in low-lying depressions. This ecosys- covered areas. These animals are able to live in tem extends as a belt south of the Himalayan conditions where food is plentiful after the rains, foothills. so that they can store this as fat that they use during the dry period when there is very little to eat. Man began to use these grasslands as pas- tures to feed his livestock when he began to domesticate animals and became a pastoralist in ancient times. Grassland Types in India: Grasslands form a variety of ecosystems that are located in differ- ent climatic conditions ranging from near desert conditions, to patches of shola grasslands that occur on hillslopes alongside the extremely moist evergreen forests in South India. In the Hima- layan mountains there are the high cold Hima- layan pastures. There are tracts of tall elephant grass in the low-lying Terai belt south of the Himalayan foothills. There are semi-arid grass- lands in Western India, parts of Central India, and in the Deccan Plateau. The Himalayan pasture belt extends upto the Terai grassland snowline. The grasslands at a lower level form patches along with coniferous or broadleaved 71 forests. Himalayan wildlife require both the for- est and the grassland ecosystem as important parts of their habitat. The animals migrate up Ecosystems Chapter3.p65 71 4/9/2004, 5:08 PM

Semiarid grassland patches of forest that occur along the streams and in depressions. The grasslands are related to repeated fires that do not permit the forest to grow. The Semi-arid plains of Western India, Cen- The grasses are the major producers of biomass tral India and the Deccan are covered by grass- in these regions. Each grassland ecosystem has land tracts with patches of thorn forest. Several a wide variety of species of grasses and herbs. mammals such as the wolf, the blackbuck, the Some grass and herb species are more sensitive chinkara, and birds such as the bustards and to excessive grazing and are suppressed if the floricans are adapted to these arid conditions. area is over grazed. Others are destroyed by re- The Scrublands of the Deccan Plateau are cov- peated fires and cannot regenerate. Thus over- ered with seasonal grasses and herbs on which used or frequently burnt grasslands are de- its fauna is dependent. It is teaming with insect graded and are poor in plant species diversity. life on which the insectivorous birds feed. How are grasslands used? Shola grassland Grasslands are the grazing areas of many rural communities. Farmers who keep cattle or goats, as well as shepherds who keep sheep, are highly dependent on grasslands. Domestic animals are grazed in the ‘common’ land of the village. Fod- der is collected and stored to feed cattle when there is no grass left for them to graze in sum- mer. Grass is also used to thatch houses and farm sheds. The thorny bushes and branches of the few trees that are seen in grasslands are used as a major source of fuelwood. The Shola grasslands consist of patches on Overgrazing by huge herds of domestic livestock hillslopes along with the Shola forests on the has degraded many grasslands. Grasslands have Western Ghats, Nilgiri and Annamalai ranges. diverse species of insects that pollinate crops. This forms a patchwork of grassland on the There are also predators of these insects such slopes and forest habitats along the streams and as the small mammals like shrews, reptiles like lowlying areas. lizards, birds of prey, and amphibia such as frogs and toads. All these carnivorous animals help to Grasslands are not restricted only to low rainfall control insect pests in adjoining agricultural areas. Certain grassland types form when clear- lands. ings are made in different forest types. Some are located on the higher steep hill slopes with What are the threats to grassland ecosys- tems? In many areas grasslands have been used for centuries by pastoral communities. Overutilization and changes in landuse of the 72 Environmental Studies for Undergraduate Courses Chapter3.p65 72 4/9/2004, 5:08 PM