CHAPTER NO: 01 1. Define the importance of Environmental Studies. Answer: Environment is derived from the French word Environ which means to encircle or surround. ENVIRONMENT is sum total of water, air, and land, inter-relationships among themselves and also with the human beings, other living organisms and property. The above definition given in Environment Act, 1986 clearly indicates that environment includes all the physical and biological surroundings and their interactions.
ENVIRONMENTAL STUDIES: It is multidisciplinary in nature covering chemistry, physics, biology, geography, mathematics, statistics, medicine, and engineering and making use of this for saving the environment for long time utilization. Scope of environmental science is broad and they are: 1. Environmental Studies is interdisciplinary in nature and needs inputs in Chemistry, Life sciences, Agriculture, Medical sciences, engineering 2.
Environmental Studies deals with the complex relationships that exist in our natural environment among people, animals, other organism water, air, soil, trees, the ocean and studying the interrelationships among biotic and abiotic components for sustainable human ecosystem. 3. Environmental Studies deals with the conservation, biodiversity, sustainable development, water management, air pollution, water pollution, soil contamination, noise pollution 4.
Carrying out impact analysis and environmental auditing for the further catastrophic activities, 5. Developing and curbing the pollution from existing and new industries, 6. Stopping the use of biological and nuclear weapons for destruction of human race, 7. Managing the unpredictable disasters and so on. Importance of Environmental Studies There are some major issues like global warming, depletion of ozone layer, depleting forests and energy resources, loss of global biodiversity etc. that are going to affect the mankind as a whole and for that we have to think globally. 1. Maintenance of environmental quality 2. Balancing the ecosystem 3. To restrict and regulate the exploitation of natural resources 4. To renovate, recycle and reuse waste material 5. To adopt engineered technology without creating negative effect on environment 6. To promote environmental education and training among people to control overpopulation and overconsumption of natural resources 7.
To formulate laws and regulation to control pollution and population 8. To focus on current environment issues: acid rain, Ozone hole, Global warming, Climate change etc. 2. What is the impact of growing population on environment? Answer: For an area to be considered overpopulated; its population reaches a point where it can’t be maintained without rapidly depleting non-renewable resources (or converting renewable resources into non-renewable ones) and without degrading the capacity of the environment to support the population.
In short, if its current human occupants are clearly degrading the long-term carrying capacity of an area, then that area is overpopulated. Consequently, some of the effects of overpopulation on natural resources include soils being damaged and forests being rapidly depleted, thus affecting natural processes such as photosynthesis, the nitrogen cycle, and a constant food source.
In addition, the depletion of water resources and extensive contribution to CO2 build-up in the atmosphere (pollution and deforestation) is vastly due to rich nations, which exponentially add to the negative impacts of overpopulation and lack of resources not only nationally, but also worldwide, as it does not only depend on their native stocks of resources, but the outsourcing to other nations for their specialized products.
Furthermore, advancements in technology and demand by such countries has increased the number of people in rich nations, which in response has come with environmental prices such as soil erosion, desertification, acid rain, global warming, destruction of the ozone layer and toxification of the entire planet. The increases in greenhouse gases with deforestation will lead add to global warming, thus increasing the temperature of the Earth. This temperature rise will lead to water level rising, and also many floods because of the lack of forests present that typically provide the soils to absorb water.
Deforestation will also lead to increased levels of CO2 because there will be no more plants to intake it. This increase of greenhouse gases leads to global warming, which also leads to increased and more severe natural disasters and loss of land with the expanding ocean (increased temperature). Also, the lack of forest area also implies lack of oxygen, which we need to breath. The trees produce some of the oxygen that we breathe in and without that oxygen, we cannot live!
Urbanization also leads to more pollution and unhealthy living because of increased use of automobiles and construction. Furthermore, deaths will be rampant because of lack of food, labor, and clean water. Another major consequence of overpopulation has been the outstanding usage of freshwater, thus leading to a major freshwater crisis that will definitely affect the future of our planet. It is also imperative to see the whole issue in perspective and how the increasing number of people in the surface of the Earth is relative to the amount of waste being produced.
Hence, the constant pollution of the environment, along with bodies of water has exponentially decreased the quantity of usable water for the future of our generations. This has critically been an issue because the oceans are mistaken for available water, but in actuality, the Earth has a finite supply of fresh water which in order to be converted from saline water to potable water, the amount of energy needed is prohibited (Ehrlich 1990). Thus water has become quite a scare commodity that few countries and civilizations seem to take into consideration. 3. Discuss the global environmental crisis in brief. Answer: )Global destruction of forests and phytoplankton in the oceans (these capture carbon dioxide – 59% land, 41% oceans – hold moisture and soil, preserve species, moderate the environment and give off oxygen). 2)World wide soil erosion and desertification (the world has lost 1/5 of its arable land in the last decade). Causes: raising beef, lumbering, use of word for fuel, clear cutting for crops or profit). 3)Worldwide burning of fossil fuels, primarily oil and coal, and burning of wood in the third world. 4)Harming of forests, lakes, and their ecosystems by acid rain (including Alaska, Canada, Norway, Eastern U.
S. , Germany, etc. ) 5)Proliferation of nuclear waste hazards, and massive amounts of other toxic waste. 6)World wide shrinking of fresh water supplied through pollution and diminishing aquifers. 7)Spreading ozone holes resulting from long lasting chlorofluorocarbon gases. 8)Massive extinction of species worldwide connected with the above factors. 9)Flooding of coastal areas world-wide as the ocean levels rise: displacing hundreds of millions of people and burying a large portion of the world’s prime agricultural lands. 10)Spread of nuclear and hi-tech weapons; wars and threat of wars in many places. 1)Close to one trillion U. S. dollars per year and immense human resources wasted world-wide. 12)World-wide sales of “conventional weapons” breeding conflicts, terrorism, dictatorships, and wars. 13)International instability, danger of nuclear, chemical, or biological weapons. 14)Global destruction of the environment through both massive military production and wars. 15)In 1900, the earth had 1 billion people, in 1950, 2 billion, in 1990, 5. 2 billion, today: over 6 billion. 16)80 million new people added to the population of the Earth every year. 7)Every person alive impacts the worlds resources and environment – first world people use 10-20 times more resources than third world people. 18)Massive migrations, starvations, wars, refugees, and economic chaos result from overpopulation. 19)Malnutrition and hunger in children leads to physically stunted and retarded human beings. 20)Most of the world’s population lives in the global south while 6-10 % of the world population live in the “first world” countries leading to global conflict between rich and poor. 21)Massive international debt of the poor countries to first world lending institutions. 2)Social and economic chaos in “third world” countries and exploitation by first world countries and their corporations. 23)This contributes to ethnic, religious, political intolerance, hatred, refugees, wars, and oppression. 24)No global means of safeguarding democracy, cultural diversity, or human rights. 25)No global means of educating people to live in an interdependent world, with social responsibility. 26)No global means of protecting human rights or achieving equal opportunity for all. 27)Systematic economic and military domination of the third world by the first world. 28)Domination of the U. N. by first world nations.
The U. N. impotent to address any of the above crises. 29)Global competition among corporations and nations for resources, ascendancy, and profits. 30)The result is an utterly unsustainable world, heading toward ever greater cataclysms and disasters, unable to solve any of the above global crises, and living at the expense of future generations. 4. If you are a social worker, how you will achieve the environment awareness among the people. Answer: If I am a social worker, I need to communicate the importance of the environment. Importance of environment: 1. Maintenance of environmental quality 2. Balancing the ecosystem . To restrict and regulate the exploitation of natural resources 4. To renovate, recycle and reuse waste material 5. To adopt engineered technology without creating negative effect on environment 6. To promote environmental education and training among people to control overpopulation and overconsumption of natural resources 7. To formulate laws and regulation to control pollution and population 8. To focus on current environment issues: acid rain, Ozone hole, Global warming, Climate change etc. The people can be made aware using many ways. 1. By mass media such as news papers, radio, television, documentary, cinema. . Each of us should be responsible for spreading the message of environmental safety to as many people as possible 3. Join the environmental group to study nature such as Bombay Natural History Society (BNHS), World Wide Fund for nature (WWF), Centre for Environment Education (CEE), etc 4. Take part in events organized on World Environment Day, Wildlife Week, world environment conferences and workshops. 5. Spreading the message of reuse, recycle, and reduce resources for long term preservation of environment and promoting eco friendly technology. 5. Explain the structural components of Ecosystem.
State the causes of soil erosion. Answer: Structural Components of Ecosystem: An ecosystem possesses both biotic and abiotic components. The non living abiotic factors include the physical and chemical features of the environment like solar energy, oxygen, CO2, water, temperature, humidity, pH, and availability of nitrogen. The living components or biotic components include all organisms like microbes, insects, plants, animals. Biotic factors are categorized as producers, consumers, decomposers. Ecosystem Structure: The living components of an ecosystem Producer (autotrophy): make food, plants, algae
Consumer (heterotrophy): eat other organisms Decomposer: eat dead organic matter; bacteria and fungi Classes of Consumers Herbivore – primary consumer – eats plants Carnivores – secondary – meat eaters; eat herbivores Tertiary – feed on carnivores Omnivores – eat plants/animals. Role of Organisms Scavengers – feed on dead organisms (vultures, flies, crows, lobsters) Detritus feeders – organisms that extract nutrients from fragments of dead organisms into more simple organic waste (termites, earthworms, crabs) Decomposers – organisms that digest parts of the dead organisms into simplest chemicals (bacteria, fungi) . Discuss the environmental problems arising from Deforestation. Answer: Some of the effects of deforestation are listed below: (Add few lines on each of the point. ) a) Effect on climate Global warming Less rainfall Hot climate. b) Effect on biodiversity Loss of medicinal plants. Loss of timber, fuel wood. c) Effect on resources Loss of land resource Loss of soil fertility Soil erosion Drastic changes in biogeochemical cycles d) Effect on economy Increase in medicinal values Demand of industrial products. e) Effect on food Loss of fruit production Loss of root based foods. . What is Food Chain? Explain. Answer: Food Chain: A food chain may be defined as, “the transfer of energy and nutrients through a series of organisms with repeated process of eating and being eaten”. In an ecosystem, all the organisms are linked together with one another by food relationship. Each organism living or dead is potential food for some other organism. A food chain is a linear sequence of links in a food web starting from a trophic species that eats no other species in the web and ends at a trophic species that is eaten by no other species in the web.
A food chain differs from a food web, because the complex polyphase network of feeding relations are aggregated into trophic species and the chain only follows linear monophagous pathways. A common metric used to quantify food web trophic structure is food chain length. In its simplest form, the length of a chain is the number of links between a trophic consumer and the base of the web and the mean chain length of an entire web is the arithmetic average of the lengths of all chains in a food web. A food chain shows how each living thing gets its food. Some animals eat plants and some animals eat other animals.
For example, a simple food chain links the trees & shrubs, the giraffes (that eat trees & shrubs), and the lions (that eat the giraffes). Each link in this chain is food for the next link. A food chain always starts with plant life and ends with an animal. Plants are called producers because they are able to use light energy from the Sun to produce food (sugar) from carbon dioxide and water. Animals cannot make their own food so they must eat plants and/or other animals. They are called consumers. There are three groups of consumers. Animals that eat ONLY PLANTS are called herbivores (or primary consumers).
Animals that eat OTHER ANIMALS are called carnivores. Carnivores that eat herbivores are called secondary consumers. Carnivores that eat other carnivores are called tertiary consumers Animals and people who eat BOTH animals and plants are called omnivores. Then there are decomposers (bacteria and fungi) which feed on decaying matter. These decomposers speed up the decaying process that releases mineral salts back into the food chain for absorption by plants as nutrients. There are always more herbivores than carnivores. In a food chain, energy is passed from one link to another.
When a herbivore eats, only a fraction of the energy (that it gets from the plant food) becomes new body mass; the rest of the energy is lost as waste or used up by the herbivore to carry out its life processes (e. g. , movement, digestion, reproduction). Therefore, when the herbivore is eaten by a carnivore, it passes only a small amount of total energy (that it has received) to the carnivore. Of the energy transferred from the herbivore to the carnivore, some energy will be “wasted” or “used up” by the carnivore. The carnivore then has to eat many herbivores to get enough energy to grow.
Because of the large amount of energy that is lost at each link, the amount of energy that is transferred gets lesser and lesser. 8. What is Food Web? Explain. Answer: FOOD WEB: Under natural conditions, the linear arrangement of food chains hardly occurs & these remains connected interconnected with each other through different types of organisms. Interlocking pattern of several interlinked food chains is termed as FOOD WEB. A food web is a graphical description of feeding relationships among species in an ecological community, that is, of who eats whom.
It is also a means of showing how energy and materials (e. g. , carbon) flow through a community of species as a result of these feeding relationships. The herbivores are usually preyed upon by carnivores, which get the energy of the sunlight at third-hand, and these again may be preyed upon by other carnivores, and so on, until we reach an animal which has no enemies, and which forms, as it were, a terminus on this food cycle. There are, in fact, chains of animals linked together by food, and all dependent in the long run upon plants.
We refer to these as ‘food-chains’, and to all the food chains in a community as the ‘food-cycle. ‘ A food web differs from a food chain in that the latter shows only a portion of the food web involving a simple, linear series of species (e. g. , predator, herbivore, plant) connected by feeding links. A food web aims to depict a more complete picture of the feeding relationships, and can be considered a bundle of many interconnected food chains occurring within the community. All species occupying the same position within a food chain comprise a trophic level within the food web.
For instance, all of the plants in the foodweb comprise the first or “primary producer” tropic level, all herbivores comprise the second or “primary consumer” trophic level, and carnivores that eat herbivores comprise the third or “secondary consumer” trophic level. Additional levels, in which carnivores eat other carnivores, comprise a tertiary trophic level. 9. Explain how the energy flows in a food chain. Answer: Nearly all organisms are dependent on energy from the Sun. Plants harness light energy to drive food production.
By the process of photosynthesis, organic compounds like glucose are made from carbon dioxide and water using this energy. Plants only absorb a small percentage of the Sun’s energy for the process of photosynthesis. The energy is absorbed in chemicals that make up the plants’ cells. Energy transfer Animals cannot make their own food so they have to eat. This is one way in which energy is transferred between organisms in an ecosystem. The energy is used for a number of life processes. In a food chain only around 10 per cent of the energy is passed on to the next level.
The rest of the energy passes out of the food chain in a number of ways: 1. via heat energy 2. is used for life processes (for example movement) 3. uneaten parts that pass to decomposers 4. is excreted and passes to decomposers. As less energy is transferred at each level of the food chain, the number of organisms at each level gets smaller. 10. How does mass and energy flow are related to ecological pyramid? Answer: An ecological pyramid (also trophic pyramid or energy pyramid) is a graphical representation designed to show the biomass or biomass productivity at each trophic level in a given ecosystem.
Biomass is the amount of living or organic matter present in an organism. Biomass pyramids show how much biomass is present in the organisms at each trophic level, while productivity pyramids show the production or turnover in biomass. Ecological pyramids begin with producers on the bottom (such as plants) and proceed through the various trophic levels (such as herbivores that eat plants, then carnivores that eat herbivores, then carnivores that eat those carnivores, and so on). The highest level is the top of the food chain.
Pyramid of biomass: An ecological pyramid of biomass shows the relationship between biomass and trophic level by quantifying the amount of biomass present at each trophic level of an ecological community at a particular moment in time. It is a graphical representation of biomass (total amount of living or organic matter in an ecosystem) present in unit area in different tropic levels. Typical units for a biomass pyramid could be grams per meter2, or calories per meter2. The pyramid of biomass may be ‘inverted’.
For example, in a pond ecosystem, the standing crop of phytoplankton, the major producers, at any given point will be lower than the mass of the heterotrophs, such as fish and insects. This is explained as the phytoplankton reproduce very quickly, but have much shorter individual lives. One problem with biomass pyramids is that they can make a trophic level look like it contains more energy than it actually does. For example, all birds have beaks and skeletons, which despite taking up mass are not eaten by the next trophic level.
In a pyramid of biomass the skeletons and beaks would still be quantified even though they do not contribute to the overall flow of energy. Pyramid of Energy: An ecosystem, of course, is a particular location on Earth, distinguished by its mix of interacting biotic and abiotic components. Ecological efficiency/energy flow (ecological efficiency is the more “scientific” of the terms) refers to the proportion of consumed energy that can be passed from one trophic level to another. At the bottom of the pyramid sit the primary producers, who, by way of photosynthesis, produce a large amount of energy.
On the next level sit the primary consumers: those who eat the primary producers. As the picture depicts, although the primary producers able to store a large amount of energy, only 10% of that energy is transferred to the next trophic level–all the rest is lost in the form of heat. This trend continues with subsequent trophic, all the way to the top of the pyramid. So by the time the tertiary consumers are eating the the secondary consumers, they are only receiving a small, small amount of energy. Biomass v T. C. 10 > Heat (9) 10kg T. C. (Snake) S. C. 100 Heat(90) 100 kg S. C. (Toads) P. C. 1000 > Heat(900) 1000 kgP. C. (Grass- hoppers) Producers 10000 Units > Heat (9000)10,000 kg Producers (Grass) Pyramid- Energy Flow Pyramid- Biomass 11. Discuss the sanitation status in developing countries. Answer: Defined as a facility which removes excreta from the risk of human contact, “safe” sanitation encompasses covered pit latrines as well as flush toilets. More Africans have access to mobile phones than toilets. The same is true in India, a country which boasts nuclear weapons and a space programme.
Development agencies must accept some responsibility, their publicity cameras preferring to linger on happy children pumping water. Latrines offer less inspiring images and copy. Even the UN’s declaration of the period 2005-2015 as the “International Decade for Action – Water for Life” betrayed neglect of sanitation, in presentation if not intent. The consequence is that global access to safe sanitation increased only from 49% to 63% in the period 1990-2010, leaving 2. 5 billion people unprotected. Open defecation, the most degrading consequence, is still practised by 1. 1 billion people, including half the population of India.
In sub-Saharan Africa, access to safe sanitation is just 30% Environmental Sanitation Holistic environmental sanitation has four main water-related aspects: water supply, rainwater drainage, solid waste disposal, and excreta disposal. Water Supply: The major problem for poor people in most countries is access to safe water in adequate quantity, with reasonable convenience, and at an affordable cost. Solutions include local grants to install household gutters and rainwater capture tanks; local wells designed to resist pollution; and small networks of water points served by a local well, borehole, or spring.
The supply problems of major cities require integrated approaches that combine demand management, leak repair, backflow prevention, wastewater reuse, and the efficient, sustainable exploitation of sources. Rainwater Drainage: Without adequate control of rainwater to mitigate floods and soil erosion, other sanitation measures can be nullified. People safe from floods and mudslides are more willing to invest in sanitation for their homes; and those in poor tropical urban areas attach a high priority to rainwater drainage.
While local communities can build local drainage, downstream obstructions can cause the backing-up of channels and rivers, requiring a watershed-wide strategy. Solid Waste Disposal: The interdependence of sanitation aspects is illustrated by the need for adequate solid waste removal to prevent the blockage of rainwater drains. Collection of refuse in hot climates must be frequent since piles attract flies and rats, and it should rely more on local labor-intensive methods rather than on expensive trucks.
For the operation to be successful requires close cooperation between the users and providers of the service, and financing must come either from municipal recurrent funds and/or user fees. Excreta Disposal: Large sewerage infrastructure projects tend to be too expensive for the vast majority of urban and rural people in developing countries, and it may be impossible to build a sewage network infrastructure in congested, narrow streets. On-site options include latrines, pourflush toilets, and septic tanks. There should be evaluated at each location according to needs and priorities.
As water use grows in villages and towns, wastewater from washing and bathing (sullage) can be cost-effectively handled by a separate drainage system coupled to on-site excreta disposal. 12. Explain the classification of ecosystem. Answer: Classification of Ecosystems: Due to the Abiotic factors, different ecosystems develop in different ways. These factors and their interaction between each other and with biotic components have resulted in formation of different types of ecosystems as explained below. Terrestrial Ecosystems: 1. Tropical Rain-Forests 2. Temperature Forests 3. Tropical Seasonal Forests 4. Temperate Deciduous Forest . Woodland and Shrub Land 6. Boreal Forest 7. Temperate Grassland 8. Tundra 9. Cultivated Land 10. Extreme desert, Rock, Sand and Ice 11. Desert/Semi-desert Shrub Aquatic ecosystems: 1. Open Oceans 2. Lakes and Streams 3. Continental Shelf 4. Estuaries and Brackish Waters 5. Swamp and Marsh 6. Upwelling Zones 7. Algal beds and Reefs Arctic and Alpine Tundra Tundra ecosystems are characterized primarily by temperature; they are extremely cold. Because of their low temperatures, they have limited plant and animal life. The Arctic tundra encircles the North Pole and extends south to the coniferous forests of the taiga.
The average winter temperature is minus 30 degrees Fahrenheit and the summer temperature ranges from 37 to 54 degrees Fahrenheit. The warmer summer temperatures allow some plant life to grow, including low shrubs and lichens. Animals include caribou, polar bears, falcons, grasshoppers and trout. Alpine tundra exists anywhere in the world where mountain elevations are so high that trees cannot grow. Alpine tundra flora is similar to the Arctic tundra and includes low shrubs, tussock grasses and heaths. Animals include mountain goats and butterflies. Forest Forest ecosystems include a broad range of landscapes.
Rainforests, Mediterranean evergreen forests, boreal forests, temperate coniferous and deciduous are all types of forest ecosystems. Boreal forests, also known as taiga, are located just south of the Arctic tundra and stretch across North America and Eurasia. The winters are long and cold, and summers are characterized by intense growth as the winter snow melts and the sun heats up the land. Boreal forests support large coniferous trees as well as lichens and moss. Wolverines, snowshoe rabbits and moose can all be found in the boreal forests. Grasslands and Savannas Grasslands, as their name suggests, are covered in grasses.
Well-known grasslands include the plains and prairies of North America, the pampas of Argentina and veldts of South Africa. Grassland temperatures vary greatly from winter to summer. Seasonal drought and occasional fires keep woody shrubs in check. Savannas are grasslands with scattered, lone trees. Nearly half of the African continent is classified as savanna. They also can be found in Australia, South America and India. Savannas receive around 20 to 50 inches of rainfall a year following a long period of drought. Desert Desert ecosystems can be classified as hot and dry, semiarid, coastal or cold.
Hot and dry deserts, like the Mojave and the Sonoran, are characterized by extremely hot days and extremely cold nights, because there is no humidity in the air to regulate the absorption and loss of the sun’s rays. Semiarid deserts include Castle Valley, Utah, and the sagebrush deserts of Montana, where summers are moderately long and dry. Coastal deserts, like the Atacama in Chile, are cooler but no less dry, receiving as little as 3 to 5 inches of rain a year. Cold deserts occur in the Antarctic and Greenland and are mostly cold and dry. Freshwater Ponds, lakes, streams, rivers and wetlands are all freshwater ecosystems.
Bodies of fresh water can vary in size from the smallest seasonal ponds to large, glacial lakes. These ecosystems can have limited species because they are isolated from each other. The ecosystem of streams and rivers can change as they flow from their headwaters to their mouths. In general, rivers and streams are cooler and clearer at their headwaters than at their mouths, so the flora and fauna vary from one end to the other. Wetlands are composed of standing water supporting a wide variety of aquatic plants. Marshes, swamps and bogs are all wetland ecosystems. Marine
Three-fourths of the Earth’s ecosystems are marine, including oceans, coral reefs and estuaries. Oceans are the largest ecosystems on the planet and vary vastly from the shallows to the depths. Coral reefs are distributed mostly in warm, shallow waters and host coral, as well as fish, sea urchins, octopus and sea stars. Estuaries are places where fresh water rivers and streams merge with the ocean. They support an interesting mix of flora and fauna including algae, seaweed, marsh grasses, mangroves, oysters and waterfowl. 13. Write a note on ‘Depleting nature of Forest as an environmental resource’. Answer:
Deforestation means destruction of forests. The total forests area of the world in 1900 was estimated to be 7,000 million hectares which was reduced to 2890 million ha in 1975 fell down to just 2,300 million ha by 2000. Deforestation rate is relatively less in temperature countries, but it is very alarming in tropical countries. Deforestation is a continuous process in India where about 1. 3 hectares of forest land has been lost. The per capita availability of forest in India is 0. 08 hectares per person which is much lower than the world average of 0. 8 hectares. The presence of waste land is a sign of deforestation in India.
Causes of Deforestation: 1. Development projects 2. Shifting cultivation 3. Fuel requirements cutting and burning 4. Construction of dams 5. Growing food needs. Some of the effects of deforestation are listed below: (Add few lines on each of the point. ) a) Effect on climate Global warming Less rainfall Hot climate. b) Effect on biodiversity Loss of medicinal plants. Loss of timber, fuel wood. c) Effect on resources Loss of land resource Loss of soil fertility Soil erosion Drastic changes in biogeochemical cycles d) Effect on economy Increase in medicinal values Demand of industrial products. e) Effect on food
Loss of fruit production Loss of root based foods. 14. Write a note on ‘Depleting nature of Minerals as an environmental resource’. Answer: Materials removed from the Earth are needed to provide humans with food, clothing, and housing and to continually upgrade the standard of living. Some of the materials needed are renewable resources, such as agricultural and forestry products, while others are nonrenewable, such as minerals. The USGS reported in Materials Flow and Sustainability (1998) that the number of renewable resources is decreasing; meanwhile there is an increasing demand for non-renewable resources.
The use of construction materials such as stone, sand, and gravel has soared. The large-scale exploitation of minerals began in the Industrial Revolution in England and has grown rapidly ever since. Today’s economy is largely based on fossil fuels, minerals and oil. The value increases because of the large demand, but the supply is decreasing. This has resulted in more efforts to drill and search other territories. The environment is being abused and this depletion of resources is one way of showing the effects. Mining still pollutes the environment, only on a larger scale. 15.
Write a note on ‘Depleting nature of Water as an environmental resource’. Answer: With increasing human population and rapid development, the world water withdrawal demands have increased many folds and a large proportion of the water withdrawn is polluted due to anthropogenic activities. Out of the total water reserves of the world, about 97% is salty water and only 3% is fresh water. Even this small fraction of fresh water is not available to us as most of it is locked up in polar ice caps and just 0. 003% is readily available to us in the form of ground water and surface water. Effects of over exploitation of water: Subsidence:
When ground water withdrawal is more than its recharge rate, the sediments in the aquifer (a layer of rock that is highly permeable and contains water) get compacted, a phenomenon knows as ground subsidence. It results in sinking of overlying land surface. Due to this structural damage in buildings, fracture in pipes etc. , occurs. Lowering of water table: Mining of groundwater is done extensively for irrigating crop fields. However, excessive mining would cause lowering of water table. Water logging: When excessive irrigation is done with brackish water it raises the water table gradually leading to water-logging and salinity problems.
FLOODS AND DROUGHT: Heavy rainfall often causes floods in the low-lying coastal areas. Prolonged downpour can also cause the over-flowing of lakes and rivers resulting into floods. When annual rainfall is below normal and less than evaporation, drought conditions are created. Causes of flood and drought: Deforestation, overgrazing, mining, rapid industrialization, global warming etc. , have contributed largely to a sharp rise in the incidence of floods. Deforestation leads to desertification and drought too. When the trees are cut, the soil is subject to erosion by heavy rains, winds and sun.
The removal of thin top layer of soil takes away the nutrients and the soil becomes useless. The eroded soils exhibit droughty tendency. Preventive measures: Clear knowledge in control of drought and desertification can be very useful for dealing with the problem. Carefully selected mixed cropping helps to optimize production and minimize the risks of crop failures. Social forestry and Wasteland development can prove quite effective to fight the problem, but it should be based on proper understanding of ecological requirement and natural process. 16.
In which manner the “Land” is one of the most vital factors for our existence? How? Answer: LAND (Add 3 to 4 lines on each point and elaborate the answer) Area of Earth=140million sq. km. = less than 1/3rd of its Surface, Vital to our Existence as it: > Preserves terrestrial Biodiversity: > Regulates Water & Carbon Cycles: > Stores Basic Resources- Groundwater, Minerals, Fossil Fuels: > Dump for solid & Liquid Waste: > Basis for Settlements & Transport/Migration Activities: 17. In which manner the “Water” is one of the most vital factors for our existence? How? Answer:
Very much important to life, Without water, human can survive for only 3 hrs For food i. e. crops water is very much essential No one survive without it, No substitute, 1/4th World population> NO ACCESS to Safe Drinking Water. Water is also very Critical Limiting Factor for Many Aspects of Life:- > Economic Growth: > Environmental Stability: > Bio-diversity Conservation: > Food Security: > Health Care: 18. Explain the structure of Forest ecosystem Answer: A forest ecosystem is one major ecologic unit that exists as “home” for a community of both native or introduced, classified organisms.
The forest ecosystem is just one of a number of unique ecosystems including prairies, deserts, polar regions and great oceans, smaller lakes and rivers. A forest ecosystem typically is associated with land masses covered in trees and those trees are often classified by foresters into forest cover types. Some ecosystems, like tundra, coral reefs, wetlands and grasslands are very fragile and very small changes can effect their health. Larger ecosystems with wide diversity are much more stable and somewhat resistant to harmful changes. A forest ecosystem community is directly related to species diversity.
Generally, you can assume that the more complex the structure, the greater is its species diversity. You should remember that a forest community is much more than just the sum of its trees. A forest is a system that supports interacting units including trees, soil, insects, animals, and man. Forest ecosystems tend to always be moving toward maturity or into what foresters call a climax forest. This maturing, also called forest succession, of the ecosystem increases diversity up to the point of old age where the system slowly collapses. One forestry example of this is growth of trees and the entire system toward an old growth forest.
When the ecosystem is exploited and exploitation is maintained or when components of the forest begins to naturally die, then the maturity of the forest ecosystem declines. Management of forests for sustainability is desirable when forest diversity is threatened by overuse, resource exploitation, old age and poor management. Forest ecosystems can be disrupted and harmed when not properly sustained. A sustained forest that is certified by a qualified certification program gives some assurance that the forest is managed to allow maximum diversity while satisfying the manager’s environmental and economic demands.
Scientists and foresters have dedicated their entire careers trying to understand even a small part of forest ecosystems. Complex forest ecosystems are extremely diverse, ranging from dry desert shrub land to large temperate rain forests. These natural resource professionals have categorized forest ecosystems in North America by placing them into forest biomes. Forest biomes are broad categories of natural tree/plant communities. Producers are plants that are at the bottom of all terrestrial food chains, and store energy from the sun in the chemical bonds within their molecules.
This energy is transferred up the food chain by consumption, creating a complex food web in which each species has links to several others, either as a predator or a prey species. Fundamental to the functioning of ecosystems is the recycling of nutrients such as carbon, nitrogen and phosphorus. When organisms die, they in turn are consumed by decomposers that break down the organic matter and return the nutrients to either the soil, or the atmosphere. Within a forest ecosystem, there is a substantial quantity of dead material, and an extensive population of decomposers.
In the wet eucalypt forests of southern Tasmania, for example, there are over 1200 species of wood-eating beetles and roughly the same number of fungi, whereas there are just 21 different mammal species. Fire is one of the dominant abiotic (non-living) factors in forest ecosystems, so many of the non-rainforest producers have developed adaptations to encourage rapid regrowth after fire events. These include dormant buds called lignotubers located at the base of the trunk, and epicormic buds which lie under the bark at intervals up the trunk.
These are stimulated to sprout and grow if the leaf canopy of the tree is removed, providing a rapid response to fire events and allowing the tree to resume photosynthesising within days. Thick bark also provides a natural defence from the heat of the fire. 19. Explain the structure of Aquatic ecosystem. Answer: An aquatic ecosystem is the way in which living organisms interact within a body of water. Essentially it describes the relationship between plants and animals within an aquatic environment. These systems exist in places such as oceans, ponds, lakes, streams and rivers.
Understanding the different components they are made from helps to explain how each one contributes to the survival of the ecosystem and its surroundings. That ecosystem which runs in a place containing water is known as aquatic ecosystem. The structure and condition of different water source are different. Various types of plants and animals can be found in water depending upon its exiting condition . In this way, there is also a close interrelationship between biotic and abiotic factors in water . Pond ecosystem can be taken an example pond ecosystem : Following biotic and abiotic factors are in pond ecosystem.
Abiotic factors: in pond abiotic factors include minerals, water , air, soil, light, heat, organic as well as inorganic materials . Biotic factors: Green plants as well as other organisms are the biotic factors of the pond . These biotic factors can be classified into there groups producer , consumer and decomposes. Aquatic plants like algae, volvox, closterium, hydrilla etc . are the producer of the pond small fish, tadepole larve ,earth worms and other small animals which depend on plants for their food are primary consumers. Similarly animals like snakes, heron which feed on secondary consumers are tertiary consumers.
After the death of consumers and producers decomposes like bacteria, fungi as well as other micro organism decompose the dead bodies mix them into soil . These decomposed materials again become the source of nutrients for the producer. In this away, this process goes on and pond ecosystem maintained. 20. Discuss the significance of the “ Ecological Pyramid” Answer: Refer Q 10 for the answer. 21. Explain various modes needed for public awareness to protect the environment. Answer: Refer Q 4 for the answer. 22. Which are the 4 main components of the environment?
Explain in brief. Elements of Environment: Answer: Atmosphere , Hydrosphere, Lithosphere, Biosphere A] Atmosphere – It includes the envelope of air surrounding the earth. Composition of air is as: Gas % (by volume) Gas %(by volume) Nitrogen 78. 08 Methane 0. 0002 oxygen 20. 94 water vapour variable Argon 0. 93 Dust variable CO2 0. 033 Nitrous oxide 0. 00005 Layers of Atmosphere are as follows: I. Troposphere: Lowest part of atmosphere which extends to about 18 km on equator and only up to 8 km on poles.
Cloud formation, thunder storm, lightning formation takes place in this zone. II. Stratosphere: Next to troposphere which extends up to 50 km. Ozone formation occurs in this zone. III. Mesosphere Next to stratosphere, extend up to about 90 Km. Burning of meteorites and their disintegration is main activity of this zone. IV. Ionosphere This layer extends up to about 350 Km. The temperature rises in this zone due to solar activity B] Hydrosphere ?This includes water bodies. ?Oceans, lakes, river, glaciers, streams, aquifers, Seas, Ice Caps. C] Lithosphere: ?It includes land (soil).
It is top most layer of earth is called crust. ?Major biological activity occurs in this region. Food is produced in this layer. ?Different kind of rocks found in lithosphere. ?Igneous rock-formed by solidification of magma. D] Biosphere ?These are the organic matter on the surface of earth comprising of all living things. ?Biosphere is responsible for grand scale recycling of energy and matter on earth. Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or on an entire planet. 23. What is atmosphere? State significance of its each layer. Answer:
Refer Q. 22 for the answer. 24. What do you understand by term “Natural Landscape”? Answer: A natural landscape is a landscape that is unaffected by human activity and contains both living and non living and are free to move and change. The nonliving elements distinguish a natural landscape from a wilderness. A wilderness includes areas within which natural processes operate without human interference, but a wilderness must contain life. The natural landscape is a place under the current control of natural forces and free of the control of people for an extended period of time. 25.
What way the natural landscape has been modified by human beings? Explain in detail Answer: Effects of human activities on the natural landscape due to his interaction with environment are as follows – Human activities like the construction of dams on rivers or using water for irrigation for agriculture affects the natural landscape and also affects the biodiversity and the distribution, quantity, and chemical quality of water resources. Human activities like the conversion of forests into agricultural land or land reclamation for human settlements affects the natural forest landscape.
A human activity like the land being converted to form industries also affects the natural landscape. Industries, human settlements, agricultural lands adversely affect the flora and fauna of that area and thus affect the food web and food chain. 26. Brief the concept of “Ecosystem”. An ecosystem is a community of living organisms (plants, animals and microbes) along with the nonliving components of their environment (things like air, water and mineral soil, energy, nitrogen), interacting as a system through a network of interactions among organisms, and between organisms and their environment.
They can come in any size but usually encompass specific, limited spaces. These components are regarded as linked together through nutrient cycles and energy flows. The energy that flows through ecosystems is obtained primarily from the sun. It generally enters the system through photosynthesis, a process that also captures carbon from the atmosphere. By feeding on plants and on one-another, animals play an important role in the movement of matter and energy through the system. They also influence the quantity of plant and microbial biomass present.
By breaking down dead organic matter, decomposers release carbon back to the atmosphere and facilitate nutrient cycling by converting nutrients stored in dead biomass back to a form that can be readily used by plants and other microbes. Ecosystems are controlled both by external and internal factors. External factors such as climate, the soil and topography, control the overall structure an ecosystem and the way things work within it. Ecosystems are dynamic entities—invariably, they are subject to periodic disturbances and are always in the process changes. There are various types of ecosystems-
Forest ecosystems Grasslands ecosystems Aquatic- fresh water as well as marine ecosystems Desert ecosystems Mangroves ecosystems 27. What do you understand by the term “Ecotone”? Answer: An ecotone is a transition area between two biomes or different patches of the landscape. It may be narrow or wide, and it may be local (the zone between a field and forest) or regional (the transition between forest and grassland ecosystems). An ecotone may appear on the ground as a gradual blending of the two communities across a broad area, or it may manifest itself as a sharp boundary line.
Changes in the physical environment may produce a sharp boundary, as in the example of the interface between areas of forest and cleared land). Elsewhere, a more gradually blended interface area will be found, where species from each community will be found together as well as unique local species. ECOTONE: a transition zone between two adjacent ecological communities, such as forest and grassland. It has some of the characteristics of each bordering community and often contains species not found in the overlapping communities.
An ecotone may exist along a broad belt or in a small pocket, such as a forest clearing, where two local communities blend together. 28. What is Ecological Toilets? Answer: Ecological sanitation (EcoSan) is based on three fundamental principles: preventing pollution rather than attempting to control pollution; rendering the urine and feces safe for reuse; and using the safe products for agricultural purposes. This approach can be characterized as ‘sanitize-and-recycle’ aiming at closing the nutrients loop. Ecological toilets use a minimum amount of water or no water at all.
The urine diverting toilets are designed to keep feces and urine (and also possibly water used for anal cleansing) separate, to permit their separate disposal. Most of the nitrogen contained in excreta is in the urine that transmits few of the diseases associated with human waste. (Schistosomiasis and typhoid are notable exceptions in certain areas). Once urine and feces are kept separate, urine can be used as a fertilizer without treatment, with minimal precautions needed to protect health. Fecal matter will also remain dry and therefore easier and more convenient to manage.
Increases in storage time, temperature, dryness, pH, ultraviolet radiation, and competing natural soil organisms are amongst the environmental factors used to enhance the treatment and composting of the fecal matter. When to use it? Consider its use when (a) there is interest in using digested fecal material, urine or both to fertilize land; (b) people understand and accept the technology; (c) significant training and monitoring is available for the proper use of this system; (d) demand for the urine and compost is demonstrable and/or (e) a high groundwater table or very rocky soil complicate excavation below the surface.
Advantages: Ecological toilets have the potential to produce valuable resources from excreta, while conserving and protecting water. Disadvantages: Ecological toilets must be operated as designed and this places greater responsibilities on users than conventional sanitation options. They should only be considered where systems to inform users and monitor the subsequent use of the latrines can be put into place. People are less likely to adopt the approach when they already have a latrine, pour flush toilet or WC. Ecological toilets are often significantly more expensive than mere pit latrines.
Technical requirements: Rather than ‘flush away’ or ‘drop and store’ wastes, the EcoSan approach stresses the reuse of wastes as resources. Some commentators advocate the addition of straw and vegetable waste to fecal wastes to optimize the carbon to nitrogen ratio in the waste and thus speed up the decomposition process. Many working in sanitation, however, are skeptical that such additional user requirements will be observed in practice. Most ecological latrines in developing countries have two chambers that are used alternately as in double pit VIPs. Many ecological toilets are or can be built entirely above ground level.
This makes the design suitable for places with a high groundwater table or hard sub-surface rock. Some designs include a panel, designed to catch and transmit solar radiation and hence heat up the contents of the vault or chamber; such heating can reduce their water content and accelerate the composting and stabilization process. 29. Which are the 4-steps taken to cater the high needs of population those cause environmental degradation? To cater high needs of population: Produce More Resources Technological Innovations Their Indiscriminate Applications Rapid Economical Growth
To overcome Environmental Degradation- Conserve Resources & Prevent unsustainable use Need for Public Awareness Prevention of Environmental Degradation must be a Part of Our Living Mass Media (Radio, TV, Newspapers) + Government Institutions + NGO Influence the Politicians + Strong Public supported Movements (Street Plays, March, Events) + Personal Awareness + Watchdogs 30. Draw a diagram of typical population Pyramid for a developing country and write brief note on morbidity.
Answer: Morbidity: Departure from a state of physical or psychological well-being, resulting from disease, illness, injury, or sickness, specially where the affected individual is aware of his or her condition. According to the World Health Organization (WHO), morbidity could be measured in terms of (1) number of persons who were ill, (2) illnesses these persons experienced, and (3) the duration of these illnesses. MaleFemale ^ ^ ^ ^ % in Age Group(X-Axis) V/s Age Groups 4 to 84 Years(Y-Axis)