Note for Environment Science - Envir By JNTU Heroes

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UNIT – I ENVIRONMENT, ECOSYSTEM AND BIODIVERSITY DEFINITION, SCOPE AND IMPORTANCE CHAPTER 1 ENVIRONMENT, SCOPE AND IMPORTANCE 1.1 Introduction: Environmental science is the study of nature and the facts about environment. Basically environment can be defined as “all the social, economical, physical & chemical factors that surrounds man” (or) “all abiotic and biotic components around man-all living and non-living things surrounds man”. 1.2 Environment Components can be divided into biotic and abiotic components. According to ancient man the environment was the Panchaboodhas (i.e) air, water, land, sky and energy. The human were disciples of nature. They were able to protect themselves from harmful one and protect the others. But according to modern man the environment is only air land and water. Exploitation of various earth resources to satisfy the increasing needs of human population has resulted in 1) depletion of various resources of earth 2) pollution. Principles of environmental education:  Examine the major environmental issues  Discover the root cause  Develop problem solving skills  Promote co-operation in solving problems  Emphasis active participation in prevention and solution to problems. 1.3 Scope of environmental science:  Studying the interrelationship between the components of env.  Carrying out impact analysis and env. Audit  Preventing pollution from existing and new industries  Stopping the use of biological and nuclear weapons  Managing unpredictable disasters etc. 1.4 Public awareness: Environmental Pollution or problems cannot be solved by mere laws. Public participation is an important aspect which serves the environmental Protection. Public awareness of environmental Is at infant stage 30-40% of public of developing country are aware of environmental. Problems but they do not bother about it.  Ignorance and incomplete knowledge has lead to misconceptions 1

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 Development and improvement in std. of living has lead to serious environmental disasters  Debate on environmental Issues are treated as anti-developmental 1.5 Reasons for environmental Ignorance: Science, technology and economics failed to integrate the knowledge on environmental Aspects in curriculum the decision makers do not process environmental Angle of decision making consideration of economic growth, poverty eradication has lead to environmental Degradation only few developmental activities are made considering the environmental Aspects. 1.6 Need For Public Awareness: The United Nations Conference on Environment and Development held at Reo de Janeiro in 1992 (popularly known as “Earth Summit”) and world summit on sustainable development at Johannesburg in 2002, have highlighted the key issues of global environmental concern. They have attracted the attention of people. Any government at its own cannot achieve the goals of clear environment until the public participate in action. Public participation is possible only when the public is aware about the ecological and environmental issues. Eg. Ban- the littering of polythene. 1.7 Methods to propagate environmental Awareness: 1. Among students through education – introducing environmental studies in the curriculum. 2. Among public through mass media- environmental programmmes through TV, radio etc. 3. Among decision makers, planners, leaders etc. 1.8 Role of NGOs 1. Advise the government in interacting with ground level people 2. Organize public meetings to create environmental awareness Eg. Recent report of “centre for science and environment‟ on permissible limits of pesticides in cola drinks. Public awareness is needed in the area 3. Study of natural resources-conservation and management 4. Ecology and biodiversity – conservation 3. environmental Pollution and prevention 5. Social issues related to development and environment 6. Human population and environment. 2

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CHAPTER 2 ECOSYSTEMS AND BIODIVERSITY 2.1 Ecosystem -living things in a given area, non-living chemical and physical factors of their environment, linked together through nutrient cycle and energy flow Types of Ecosystem Artificial/Man-made Natural Terrestrial Aquatic Marine Fresh water Lotic -river, stream or spring. Lentic -lake, pond or swamp. 2.2.1 Ecology - Study of the distribution and abundance of organisms, the flows of energy and materials between abiotic and biotic components of ecosystems. 2.2 Ecosystem Structure: The living components of an ecosystem • The roles of organisms in an ecosystem: • Producer (autotrophy): make food; plants, algae • Consumer (heterotrophy): eat other organisms • Decomposer: eat dead organic matter; bacteria and fungi 2.2.1 Classes of Consumers Herbivore – primary consumer – eats plants Carnivores – secondary – meat eaters; eat herbivores Tertiary – feed on carnivores Omnivores – eat plants/animals. 2.2.2 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) 3

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Fig. 2.2.2 Role of organisms 2.3 FOREST ECOSYSTEM (TERRESTRIAL ECOSYSTEM) 2.3.1 Introduction  A forest is an area with a high density of trees.  World’s total land area is 13,076 million hectares - (Source: FAO; 1989)  Of which total forests account for about 31% of the world’s land area.  In India, the forest cover is roughly 19% of the total land area.  The forest ecosystems are of great concern from the environmental point of view.  It provides numerous environmental services like;  Nutrient cycling,  Maintaining biodiversity  Providing wildlife habitat  Affecting rainfall patterns  Regulating stream flow  Storing water  Reducing flooding  Preventing soil erosion  Reclaiming degraded land & many more….  Apart from environmental values, forest ecosystems have some traditional values as well.  Examples are:  Fire Wood & Timber.  Fruits.  Gums.  Herbs & drugs. 4