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1, , Unit -1, ENVIRONMENT AND ECOSYSTEM, After going through this chapter, you will be able to understand the, following features:, 1.1, Objectives, 1.2, Introduction, 1.3, Subject discussion, 1.4, Environment, a. Definition of Environment, b. Nature, Scope and Importance of Environment, c. Components of Environment, 1.5, Ecosystem, d. Concept and Definition of Ecosystem, e. Functioning and Structure of Eco-System, f. Types of Ecosystem, 1.6, Man-Environment Relationship, 1.7, Importance and Scope of Environmental Studies, 1.8, Summary, 1.9, Check your Progress/Exercise, 1.10 Answers to the self-learning questions, 1.11 Technical words and their meaning, 1.12 Task, 1.13 References for further study, , 1.1. OBJECTIVES, By the end of this unit you will be able to –,  Understand the concept, definition, nature, scope and, importance of environment and ecosystem,  Understand the relationship between man and environment,  Understand the importance of environmental studies, , 1.2. INTRODUCTION, Now a day the word Environment is often being used by, allmost all the people surrounds us, on the television and, newspapers are focusing different environment related news

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2, regularly. Everyone is speaking about the protection of the, environment. Global summits held regularly to discuss the, environmental issues. During the last few years, the mutual, relationship among the environment, social organization and culture, has been discussed in sociology, geography and anthropology. All, shows the increasing importance of the environment., , Fig. 1.1, Environment is the source of life on the Earth and, determines the existence, growth and development of mankind and, all its activities. Primitive man relied heavily on the nature for their, survival. But man, among the all living being, is the most intelligent, and capable to modify his surrounding to suit his requirements., Therefore, continuous interactions of man and environment cause, different global, regional and local problems. With the development, of modern technology, there is always a growing pressure on the, environment. These dynamic relations between man and, environment become the primary concern for every one for the, survival of the future generation. The concern about the, environment has existed for a long time but the development in last, fifty years so have some environmental issues among the public., The concern of environment arises from the desire to improve the, quality of life., , 1.3. SUBJECT DISCUSSION, Throughout time, humans have learned to exist at many, locations on the earth. The interaction of humans with the, environment (surroundings) in these locations has often brought, major changes in that environment. Some changes were good,, some were bad. Many times, the bad changes were caused by, humans making too much of a change in the environment, by using, or abusing the natural resources (anything found in nature) present.

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3, Every location where people have lived contained a community of, plants, animals, insects, and other natural resources. A community, of organisms, other natural resources, and their influence on each, other is called an ecosystem. The plants and animals existing in an, ecosystem are those most adapted to that environment., , Fig. 1.2 Different elements in the environment, A growing, human, population, presents, increasing, environmental challenges around the world. The study of, Environment and Ecosystem helps in understanding the dynamics, of ecology, environmental science, and conservation management, of natural resources, wildlife and sustainable ecosystems and, landscapes so that applicable solutions can be sought for., , 1.4. ENVIRONMENT, a., , Definition of Environment:, , The word “ENVIRONMENT” originated from a French word, “Environia”, which means “around” or to surround or to, encompass or to encircle., , Fig. 1.3 Environment

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4, This means that environment includes things or objects or, events that surround us. It is believed that the subject has been, introduced by the biologist Jacob Van Enkul in the early 1900s., , , , , , , , “The environment is the sum total of all conditions, agencies, and influences which affect the development, growth, life and, death of an organism, species or race”. (The Universal, Encyclopedia)., German scholar Fitting (1922) defined environment as “the, totality of milieu factors of an organism”., Transley (1926) a plant ecologist described the environment as, the “sum total of those effective conditions in which organism, live”., According to the American anthropologist Herskovits (1948),, “environment is the sum of all those external conditions and, influences, which affect the life and development of human, being”., , From the above definitions, we learn that:,  Environment refers to everything that surrounds us in which we, live.,  Any external force which affects the life of an organism is a part, of environment.,  Environment is a multi-directional system of interaction.,  Environment is the complex of many variables.,  Environment is a dynamic concept as it changes according to, time and space.,  It is the sum total of conditions which affect the development, and growth of any organism., The environment is a complex of many variables which, surrounds man as well as all living organisms. This means, environment includes things or events surrounding us and their, interaction., , and, , Fig. 1.4 Man-Environment Relationship, It is an interaction between living beings (plants/ animals), their environment, which includes physical non-living

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5, components like air, river, ocean or land, mountain, plateau etc. It, also includes interaction among living beings. It is thus a multi, directional system of interaction. The system is made of living and, non-living physical components of Earth., b., , Nature and Scope of Environment:, The environment is very complex in nature. It is a mixture of, living and non-living components that are interrelated to each other, yet are independent. The environment is comprehensive in nature;, as it includes everything surround us. The most important property, of environment is its potential to change or dynamism. Both biotic, and abiotic components have the potential to change., , Fig. 1.5 Changes in the Biotic and Abiotic factors, The other character of environment is it lies in his system., The functioning of environment always follows a systematic order., The hydrological cycle is the best example of a systematic order or, sequence of the events in the environment., , Fig. 1.6 Hydrological Cycle, , The scope of environment lies in the components of, environment. However, with alterations brought in the components,, the scope has widened to include their necessary protection and

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6, sense of proper utilization. It thus enables man to accept his, environmental responsibilities., c., , Components of Environment:, Environment is a complex phenomenon of different factors, which are the product of the forces and processes of nature. It, comprises of number of factors that interact with each other in, different ways to keep the planet alive and support the life on the, earth. Environmental factors influence the living being in several, , a), b), c), d), e), , Natural Vegetation, Animals, Insects, Birds, Fish, , ways. Organisms continuously take the things they need from the, environment and depend entirely on their environment for their, survival. Different living beings live in different habitats due to, differences, in needs for survival., , Fig. 1.7 Different biotic elements and their environment

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7, The components of the natural environment can be, classified into two broad groups:,  ABIOTIC or Non-living.,  BIOTIC or Living., There is also a Man-made environment.,  Abiotic or Non-living Components, , The abiotic or non-living components are all those physical, and chemical factors which influence the life of the living beings., , Fig. 1.8 Abiotic factors, , Fig. 1.9, o Lithosphere:, Lithosphere is the outer Layer of the solid earth. It consists, of minerals occurring in the earth’s crust and the soil. For example:, minerals, organic matter, air, water. The abiotic components, associated with lithosphere are as follows:

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8, , Fig. 1.10 Major components of the Earth, , , Location: Location is the main factor as it influences the human, activities. There are two types of location viz. Absolute location, and Relative location., Location, Absolute, , , , Relative, , Absolute location is referred to the actual location on Earth’s, surface with respect to geographical coordinates (in terms of, latitudes and longitudes)., , Fig. 1.11 Absolute location - Graticule

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9, , Fig. 1.12 Absolute Location of Mumbai, , , Relative location can be defined as the location with reference, to a reference point. The references may be natural or manmade., , Fig. 1.13 Relative Location, , , Coastline: The nature of the coastline also plays an important, role as trade is dependent on waterways. The development of, ports and harbours for international trade depends on the nature, of coastline., Sea, , Coast, Line, , Indented Coast Line, , Fig. 1.14 Nature of coastline

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10, , , Size and Shape of Country: The countries vary in their shape, and size. Some of the countries are large like U.S.A, Canada,, Russia and they can enjoy the large amount of resources., Smaller countries like Japan, Sri Lanka have limitation in, resource utilization., , Big Countries - 1) Canada 2) USA 3) Russia, Small Countries - 4) Japan 5) Sri Lanka, Fig. 1.15 Large & Small Countries, Shapes of the countries may be elongated, fragmented or, compact., , Fig. 1.16 Shapes of the Countries

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11, Hydrosphere:, The hydrosphere consists of all the water bodies on earth, surface, ocean, seas, river and lakes that consists 71% of the earth, surface. This includes water in liquid and frozen forms in, groundwater, oceans, lakes and streams. Saltwater accounts for, 97% of this amount. Fresh water accounts for only about 3%. Of, this fresh water, 2% is in the form of ice and permanent snow cover, in the Arctic, the Antarctic, and mountain glaciers. Only less than, 1% of the fresh water on Earth is in easily accessible lakes,, reservoirs and river systems. It is essential for living., o, , Water - Salty, (Ocean &, Sea), , Fig. 1.17 Water on the Earth, Atmosphere:, The Atmosphere is a transparent envelope of gases and, suspended particles that surround the Earth. Without atmospheric, gases, life could not exist. Even the physical processes that, operate in the atmosphere are of vital importance because they are, responsible for the Earth's varied climates. The atmosphere of, Earth is mostly composed of nitrogen. It also contains oxygen used, by most organisms for respiration and carbon dioxide used by, plants for photosynthesis. The atmosphere helps protect living, organisms from genetic damage by solar ultraviolet radiation, solar, wind and cosmic rays., o, , The Atmosphere is the source of every living thing in the, world. It plays a very important role in serving the world's needs., The ozone layer in the atmosphere is a matter of tremendous, concern as it profoundly influences the environmental conditions.

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12, , Fig. 1.18 layers of the Atmosphere, The Atmosphere is divided into layers according to major, changes in temperature. Atmosphere consists of five main layers., From highest to lowest, the five main layers are:, , Fig. 1.19 Structure of the atmosphere, , , Biotic or Living Components, , Living components form the layer called Biosphere., o, , Biosphere, , Biosphere is defined as that part of the Earth and, atmosphere in which ecosystems exist and operate. The area of, contact and interaction between these components is really

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13, important for life, for it is here that the entire life is confined and the, basic processes of life like photosynthesis and respiration occur.All, the living organisms are, mostly, confined to the parts of biosphere, that receive solar radiation during the day. Different living, organisms are termed as:, I. Fauna includes all animals of lower and higher order., , Fig. 1.20 Fauna, II. Flora includes vegetation, both under water and above land., , Fig. 1.21 Flora, III. Soil can be defined as the organic and inorganic materials on, the surface of the Earth that provides the medium for plant, growth. Soil develops slowly over time and is composed of, many different materials., , Fig. 1.22 Elements of soil

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14, There are three main components of biosphere. They are:, o Producers: The autotrophic organisms who make their own, food, mainly green plants., o Consumers: The heterotrophic organisms who depend on, producers for their food., o Decomposers: Bacteria and fungi belong to this category. They, breakdown the dead organic materials of producers (plants) and, consumers (animals) for their food and release energy into the, environment., , Fig. 1.23 Producer, Consumer & decomposer, , , Man-Made Environment, Man can modify the surroundings according to his wants., Man has developed some environmental components using his, intelligence, knowledge, skill and power. These Man-made, environments are as follows:, , Fig. 1.24 Transformation of Natural Environment into Cultural, Environment

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15, o, A socio cultural environment is a population, and it is, described with special attention paid to social and cultural factors., It includes cultural norms, demographic information and religious, information. A set of beliefs, customs, practices and behavior that, exists within a population are a part of it., o, The political environment is the state, government and its, institutions and legislations and the public and private stakeholders, who operate and interact with or influence that system. The, government plays a significant role in economic development of, country. Different governmental systems are followed by the, different Countries., o, Economic Environment: different countries follows different, economic environment like capitalism, socialism and many others., , 1.5. ECO-SYSTEM, a., Concept and Definition of Eco-system, An ecosystem includes all the living things (plants, animals and, organisms) in a given area, interacting with each other, and also, with their non-living environments (weather, earth, sun, soil,, climate,)., , Fig. 1.25 Ecosystem, The term ecosystem was coined by A. G. Tansley in 1935,, who defined it as “the system resulting from the integration of all the, living and non-living factors of the environment”, According to R. L. Lindeman (1942), the term ecosystem, applies to “any system composed of physical-chemical-biological, processes within a space-time unit of magnitude.”, According to Monkhouse and Small, “ecosystem is an, organic community of plants and animals viewed within its physical, environment or habitat”.

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16, From the above definitions of ecosystem, the following basic, properties emerge:,  Ecosystem of any given spatial- temporal unit represents the, sum of all living organisms and physical environment.,  It is a well-defined area.,  It is an open system characterized by continuous input and, output of the energy.,  It is mainly powered by solar energy.,  It is a functional unit.,  There is a complex interaction between the biotic and abiotic, components.,  Ecosystems are natural systems and are well organized., b., , Functioning and Structure of Eco-System:, Ecosystems maintain themselves by cycling energy and, nutrients obtained from external sources. There are different trophic, levels that exist in an ecosystem., 1. Primary producers (plants, algae, and some bacteria) use solar, energy to produce organic plant material through, photosynthesis., 2. Herbivores—animals that feed solely on plants—make up the, second trophic level., , Fig: 1.26 Functioning of Ecosystem, 3. Predators that eat herbivores comprise the third trophic level; if, larger predators are present, they represent still higher trophic, levels., 4., Organisms that feed at several trophic levels (for example,, grizzly bears that eat berries and salmon) are classified at the, highest of the trophic levels at which they feed., 5., Decomposers, which include bacteria, fungi, molds, worms,, and insects, break down wastes and dead organisms and return, nutrients to the soil.

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17, Thus, the energy is obtained from the sun and then passed, through the environment and the process is known as Energy, Flow. All the energy or nutrients flow through the ecosystem in a, cyclic order, known as nutrient cycles., Any food chain or energy flow cycle includes three major, components viz. producers, consumers and decomposers., Producers, The green plants have chlorophyll with the help of which, they trap solar energy and change it into chemical energy of, carbohydrates using simple inorganic compounds namely water, and carbon dioxide., o, , Fig. 1.27 Photosynthesis, This process is known as photosynthesis. As the green, plants manufacture their own food they are known as Autotrophs, (i.e. auto = self, trophos = feeder). The chemical energy stored by, the producers is utilized partly by the producers for their own, growth and survival and the remaining is stored in the plant parts, for their future use., , Consumers, The animals lack chlorophyll and are unable to synthesize, their own food. Therefore, they depend on the producers for their, food. They are known as heterotrophs (i.e. heteros = other, trophos, = feeder). Consumers can be classified into different orders:, o, , , , Primary Consumers or First Order Consumers or, Herbivores: These are the animals which feed on plants or the, producers. They are called herbivores. Examples are rabbit,, deer, goat, cattle etc.

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18, , , Secondary Consumers or Second Order Consumers or, Primary Carnivores: The animals which feed on the herbivores, are called the primary carnivores. Examples are cats, foxes,, snakes etc., , , , Tertiary Consumers or Third Order Consumers: These are, the large carnivores which feed on the secondary consumers., Example is Wolves., , , , Quaternary Consumers or Fourth Order Consumers or, Omnivores: These are the largest carnivores which feed on the, tertiary consumers and are not eaten up by any other animal., Examples are lions and tigers., , Decomposers or Reducers:, Bacteria and fungi belong to this category. They breakdown, the dead organic materials of producers (plants) and consumers, (animals) for their food and release into the environment the simple, inorganic and organic substances produced as by-products of their, metabolisms.The decomposers are known as Saprotrophs (i.e.,, sapros = rotten, trophos = feeder), o, , Fig: 1.28 Energy Flow in Ecosystem, On an average, only about 10 percent of net energy, production at one trophic level is passed on to the next level., Processes that reduce the energy transferred between trophic, levels include respiration, growth and reproduction, defecation, and, non-predatory death (organisms that die but are not eaten by, consumers)., Food Chain

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19, A food chain is a linear network of links in a food web starting, from producer organisms (such as grass or trees which use, radiation from the sun to make their food) and ending at apex, predator species (like grizzly bears or killer whales), detritivores, (like earthworms or woodlice),, or decomposer species, (such, as fungi ). A food chain also shows how the organisms are related, with each other by the food they eat. Each level of a food chain, represents a different trophic level. A food chain differs from a food, web, because the complex network of different animals and the, chain only follows a direct, linear pathway of one animal at a time., , Fig:1.29 Food Chain, Generally, we find two types of food chains:, I., , Grazing food chain: It starts with green plants and goes to, grazing herbivores and on carnivores., , II., , Detritus Food chain: It goes from dead organic matter into, micro-organisms and then to organisms feeding on detritus, and their predators., , Fig. 1.30 Food Chains

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20, , Fig. 1.31 Food Webs, Food Web, A food web (or food cycle) is the natural interconnection, of food chains . For example, in grazing food chain of a grass land,, in the absence of rabbit, grass may also have eaten by mouse. The, mouse in turn may be eaten directly by hawk or by a snake first, which is then eaten by hawk. Thus, in nature there exists an, alternative, which all together constitute an interlocking pattern, called food web., In a food web in grass land:, I., Grass---Grasshopper—Hawk., II. Grass---Grasshopper—Lizard-------Hawk., III. Grass---Rabbit-----Hawk., IV. Grass---Mouse—Hawk., V. Grass---Mouse—Snake-Hawk., Ecological Pyramid, An ecological pyramid is a graphical representation, designed to show the biomass or bioproductivity 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., Energy 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., An energy pyramid of biomass shows the relationship, between biomass and trophic level by quantifying the biomass, present at each trophic level of an energy community at a particular, time. It is a graphical representation of biomass (total amount of, living or organic matter in an ecosystem) present in unit area in

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21, different tropic levels. (Typical units are grams per meter2, or, calories per meter2.), , Fig: 1.32 Energy and Ecological Pyramid, Bio-Geo-Chemical Cycle, Biogeochemical cycle is a pathway by which a chemical, substance moves through both biotic (biosphere) and abiotic, (lithosphere, atmosphere, and hydrosphere) compartments of, Earth. Water, for example, is always recycled through the water, cycle, as shown in the diagram. The water undergoes evaporation,, condensation, and precipitation, falling back to Earth. The other, important cycles are the carbon cycle, nitrogen cycle, oxygen cycle,, phosphorus cycle, sulfur cycle etc., , Fig. 1.33 Hydrological Cycle, c., , Types of Ecosystem, There are many types of ecosystems, but the three major, classes of ecosystems, sometimes referred to as ‘biomes’, which, are relatively contained, are the following:, , Freshwater Ecosystems, , Terrestrial Ecosystems, , Ocean Ecosystems

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22, Freshwater Ecosystems, Freshwater ecosystems are found in sources of fresh water, like the following:, o, , , , Pond Ecosystems – These are usually relatively small and, controlled. Most of the time they include various types of plants,, amphibians and insects and fishes., , , , River Ecosystems – Because rivers always link to the sea,, they are more likely to contain fish alongside the usual plants,, amphibians and insects. These sorts of ecosystems can also, include birds because birds often hunt in and around water for, small fish or insects., , Freshwater ecosystems are the smallest of the three major, classes of ecosystems, accounting for just 1.8% of the total of the, Earth’s surface. The smallest living part of the food web of these, sorts of ecosystems is plankton, a small organism that is often, eaten by fish and other small creatures., Terrestrial Ecosystems, Terrestrial ecosystems are many due to natural diversity on, Earth. Some of the most common terrestrial ecosystems are as, follows:, o, , , , Rainforests – Rainforests usually have extremely dense, ecosystems because there are many different types of animals, all living in a very small area., , , , Tundra -Tundra usually have relatively simple ecosystems, because of the limited amount of life that can be supported in, these harsh conditions., , , , Deserts –Desert also have harsh conditions, more animals live, in the extreme heat than live in the extreme cold of Antarctica,, for instance., , , , Forests – There are many different types of forests all over the, world including deciduous forests and coniferous forests. These, can support a lot of life and can have very complex ecosystems., , , , Grasslands – Grasslands support a wide variety of life and can, have very complex and involved ecosystems., , , , Wetlands-A wetland is a land area that is saturated with water,, either permanently or seasonally, such that it takes on the, characteristics of a distinct ecosystem. Wetlands are also, considered the most biologically diverse of all ecosystems,, serving as home to a wide range of plant and animal life., , Marine Ecosystem, Marine, ecosystems are, Earth's aquatic, ecosystems, salt, o, , among, the, largest, of, marshes, intertidal, zones,

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23, estuaries, lagoons, mangroves, coral reefs, the deep sea, and, the sea floor. They can be contrasted with freshwater ecosystems,, which have a lower salt content. Marine waters cover two-thirds of, the surface of the Earth. Such places are considered ecosystems, because the plant life supports the animal life and vice versa., , 1.6. MAN AND ENVIRONMENT RELATIONSHIP, Since inception, man has been dependent on the, environment for his food, clothing and shelter and other basic and, luxurious needs. His relationship with the environment has shown, dynamism. At times, he was and is friendly with nature and at times, not, but, he never destroyed the environment. Lately, with changing, nature of man’s activities and style of living, environment has, undergone certain negative changes. Thus, the relationship, between man and environment is become painful.Man started, changing the natural environment to suit his needs. So, he, exploited, altered and modified his natural environment. Scientific, and technological advancements enabled man to exploit his natural, environment. This resulted in destruction, degradation and damage, to the natural environment giving rise to disaster. The results are, observed and experienced in the form of ozone depletion, global, warming, threats to bio-diversity, acid rain, desertification, pollution,, flooding, etc. only education, awareness and conscience can help, restore the environment and stop further loss., , 1.7. IMPORTANCE AND SCOPE OF, ENVIRONMENTAL STUDIES, The scope of environmental studies is very large., Environmental studies constitute knowledge of many disciplines of, natural sciences, social sciences and humanities, biology,, chemistry, law, sociology, anthropology and ethics and many other, disciplines. With this interdisciplinary knowledge environment, studies involve developing a sense of the spirit of the environment, or our surroundings, in a large context. Environmental studies is the, scientific study of the environmental system and the status of its, inherent or induced changes on organisms. It includes not only the, study of physical and biological characters of the environment but, also the social and cultural factors and the impact of man on, environment., According to UNESCO, environmental studies are:, (a), , (1971),, , the, , objectives, , of, , Creating the awareness about environmental problems among, people.

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24, (b), , Imparting basic knowledge about the environment and its, allied problems., , (c), , Developing an attitude of concern for the environment., , (d), , Motivating public to participate in environment protection and, environment improvement., , (e), , Acquiring skills to help the concerned individuals in identifying, and solving environmental problems., , (f), , Striving to attain harmony with Nature., , In today’s world because of industrialization and increasing, population, the natural resources has been rapidly utilised and our, environment is being increasingly degraded by human activities, so, we need to protect the environment. It is not only the duty of, government but also the people to take active role for protecting the, environment, so protecting our environment is economically more, viable than cleaning it up once, it is damaged. Therefore,, environmental studies also play an important role for sustainable, development of environment., The importance of environmental studies can be summarized, as follows:, 1. To clarify modern environmental concept like how to conserve, biodiversity., 2. To know the more sustainable way of living., 3. To use natural resources more efficiently., 4. To know the behavior of organism under natural conditions., 5. To know the interrelationship between organisms in populations, and communities., 6. To aware and educate people regarding environmental issues, and problems at local, national and international levels., , 1.8. SUMMARY, Environment is the source of life on the earth and, determines the existence, growth and development of mankind and, all its activities. The interaction of humans with the environment, (surroundings) in these locations has often brought major changes, in that environment. Some changes were good, some were bad., The environment is a complex of many variables which surrounds, man as well as all living organisms. The environment is complex,, dynamic and systematic in nature. The biotic components and, abiotic components together make up the environments. There, exists man made environment that is helping man to lead a smooth, life.

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25, The term ecosystem was coined by A.G. Tansley in 1935,, who defined it as “the system resulting from the integration of all the, living and non-living factors of the environment”. Ecosystems, maintain themselves by cycling energy and nutrients obtained from, external sources. There are different trophic levels that exist in an, ecosystem. Any food chain or energy flow cycle includes three, major components viz. producers, consumers and decomposers., A food chain is a linear network of links in a food web starting, from producer, organisms (such, as grass or trees which, use, radiation from the sun to make their food) and ending at apex, predator species (like grizzly bears or killer whales), detritivores, (like earthworms or woodlice),, or decomposer species, (such, as fungi ). A food web (or food cycle) is the natural, interconnection of food chains. An ecological pyramid is a, graphical representation designed to show the biomass or bio, productivity at, each trophic, level in, a, given ecosystem., Biogeochemical cycle is a pathway by which a chemical, substance moves through both biotic (biosphere) and abiotic, (lithosphere, atmosphere, and hydrosphere) compartments of, Earth., The relationship between man and environment is crucial to, man’s existence and has always changed with time. This is, resulting in disasters and loss of life, property and health. This, needs to be controlled for sustainable living., With its interdisciplinary knowledge environment studies, involve developing a sense of the spirit of the environment or our, surroundings, in a large context., , 1.9. CHECK YOUR PROGRESS/EXERCISE, 1., , True or False, , a. The relationship between man and environment has remained, static, b. The term environment means interaction of all living and nonliving things in the surroundings, c. The term ecosystem has been coined by A.G. Tansley, d. Marine ecosystems are found in rivers and ponds, e. Environmental studies has an interdisciplinary approach, 2., , Fill in the Blanks, , a. ______________________ are, Earth's aquatic ecosystems, , among, , the, , largest, , of

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26, b. The word “ENVIRONMENT” originated from a French word, “Environia”, which means ________, c. The Atmosphere is divided into layers according to major, changes in _____________, d. Energy pyramids begin with ___________ on the bottom, e. ________________support a wide variety of life and can have, very complex and involved ecosystems., 3., Multiple Choice Questions, a.The topmost layer of the atmosphere at 700 to 10,000kms, is_________, i. Ionosphere ii. Hydrosphere iii. Exosphere iv. Mesosphere, b. ____________ helps in the decomposition of the dead matter in, a food chain, i. Herbivores ii. Detritivores iii. Autotrophs iv. Carnivores, c. The energy flow from one trophic level to other trophic level is, only ________, i. 50%, ii. 100%, iii. 20%, iv. 10%, d. ______________ order consumers are the largest carnivores, which feed on the tertiary consumers and are not eaten up by any, other animal, i. First order ii. Second order iii. Third Order iv. Fourth Order, e. The smallest living part of the food web of marine ecosystems is, _____________, a small organism that is often eaten by fish and, other small creatures., i. Small fishes ii. Plankton, iii. Worms, iv. Weeds, , 1.10. ANSWERS TO THE SELF-LEARNING, QUESTIONS, 1. True or False, 1.a. False, 1.b. True, 1.c. True, 1.d. False, 1.e. True, 2. Fill in the Blanks, 2.a. Marine ecosystems, 2.b. Around, 2.c. Temperature, 2.d. Producers, 2.e. Grasslands, 3. Multiple Choice Questions

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27, 3.a. Exosphere, 3.b. Detritivores, 3.c. 10%, 3.d. Fourth order, 3.e. Plankton, , 1.11. TECHNICAL WORDS AND THEIR MEANINGS, , , Environment: The environment is the sum total of all, conditions, agencies and influences which affect the, development, growth, life and death of an organism, species or, race, , , , Ecosystem: Ecosystem is an organic community of plants and, animals viewed within its physical environment or habitat, , , , Food chain: A food chain is a linear network of links in a food, web starting from producer organisms and ending at apex, predator species detritivores or decomposer species, , , , Food web: A food web (or food cycle) is the natural, interconnection of food chains, , , , Ecological pyramid: An ecological pyramidis a graphical, representation, designed, to, show, the biomass or bio, productivity at each trophic level in a given ecosystem, , , , Biogeochemical cycles: Biogeochemical cycle is a pathway by, which a chemical substance moves through both biotic and, abiotic compartments of Earth., , 1.12. TASK, Collect examples of food chains from all types of, ecosystems and represent them using pictures. Put some useful, information and support your chart with a map of the location of the, ecosystem., , 1.13. REFERENCES FOR FURTHER STUDY, , , Environmental Studies, Bagad Anjali, , , , Sustainable Urban Environments: An Ecosystem Approach,, Beuren, Allan et. Al., , , , The Sage Handbook of Environment and Society, Ward,, Hugh eds., , , , Environment and Sustainable Development, Sundar, I., , 