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Environmental science


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Environmental science

  2. 2. ENERGY FLOW • Movement of energy through ecosystems • Foundation of life (Sustains the life) • Limits the abundance and richness of life • ECOSYSTEM ENERGY • Sun(outside source)- the ultimate source of energy • Ecosystem energy do not circulate • Energy flow is a one way path • Energy is utilized and converted to heat (demand for food) • Continues flow of energy is required to keep the biological process active
  3. 3. • Energy entering pathways are 2. – By the primary producers(Auto trophs) – By the wind current or air convection through soil ENERGY FLOW
  4. 4. FOOD CHAIN • One way of representing Energy flow • Transfer of food from plants(producers) through herbivores-carnivores-decomposers • Above process repeats in stages • The simple stages of eating and being eaten is the FOOD CHAIN – 1. Grass-deer-lion – 2. seed-mouse-owl
  5. 5. FOOD CHAIN • Types – Grazing food chain – Detritus food chain
  6. 6. FOOD CHAIN
  7. 7. FOOD CHAIN • Grazing food chain depends on solar energy • Detritus food chain do not depends on solar energy • TOPHIC LEVEL • Feeding status of an ecosysytems • Organisms feed on plants belongs to same steps or trophic level • Number of trophic levels depend on the population of species and distribution of food Eg: Wheat->Man : Algea->insects->fish->man
  8. 8. FOOD WEB • Series of interconnected food chains terrestrial food web
  9. 9. FOOD WEB • Linear arrangements of food chain is difficult
  10. 10. ECOLOGICAL PYRAMIDS • Graphical representation of trophic structure of ES • Relationship b/w energy • 3 types – Pyramid of NUMBERS – Pyramid of BIOMASS – Pyramid of ENERGY
  11. 11. ECOLOGICAL PYRAMIDS • Pyramid of Number – Number of individual in a trophic level – The length of the bar represents the population – Progressive decrease in numbers from producers to consumers P C1 C2 C3
  12. 12. ECOLOGICAL PYRAMIDS • Pyramid of Biomass – Based on the total dry weight of living material – Total number of population X av. Weight of pop.= Biomass • Pyramid of Energy - Based on rate of energy flow - Takes upright form always - Energy will be lost in the Upper levels
  13. 13. ECOLOGICAL SUCCESSION • Process through which the ES tends to change over a period of time • Causes of ecological succession – Initial cause Climatic causes: wind, fire, erosion Biotic causes: activities of living creatures – Ecesis cause Migration, competition, aggregation, – Stabilisation causes Stabilisation of community Reason:climate
  14. 14. ECOLOGICAL SUCCESSION • Types of succession – Primary and secondary – Primary succession It is the initial development of ecosystem Community occupies on an unoccupied site Ex: forest on a new hardened lava form Forest on a retreating glacier - Secondary succession Re-establishment of ecosystem In this remnants of previous biological community, organic matters of previous community
  15. 15. ECOLOGICAL SUCCESSION • Characteristics It is unidirectional in nature Modifies the physical env It is predictable It involves various developmental stages AUTOTROPHIC SUCCN. HETROTROPHIC SUCCN. Wide spread in nature Localized in nature Starts in Inorganic env. Organic env. Early dominance of Autotrophs Early dominance of Hetrotrophs(bacteria, fungai) Energy flow is maintained indefinitely Energy flow is limited
  16. 16. MAJOR CYCLES IN ECOSYSTEM • WATER CYCLES • Rain water partly flows to river and partly get infiltrated • Stored for an year • Water is taken by the plants • By Transpiration from leaves water escapes • Condensate and the precipitate • From the water body: Evaporation-condensation- precipitation • This cycle continues
  18. 18. MAJOR CYCLES IN ECOSYSTEM • CARBON CYCLE • Carbon included in ABIOTIC and BIOTIC parts • Building block • Plants takes CO2 + Light fixationcarbohydrates • Plants gives out O2 • Hetrotrophs gives out CO2 • OXYGEN CYCLE • It is a part of Carbon cycle
  20. 20. MAJOR CYCLES IN ECOSYSTEM • NITROGEN CYCLE • Plants take nitrogen from the soil • Waste material from the animals get broken down by the bacteria • Ammonia get digested by the bacteria convert it into Nitrites • Nitrate fixing bacteria convert Nitrate to Nitrites
  22. 22. CATEGORIES OF ECOSYSTEM • GRASSLAND ECOSYSTEM • Terrestrial ecosystem • Rainfall is low(250mm-600mm), soil is of poor quality • Major community is grass with few trees • Abundant grazing animal • Soil rich in humus • Occupies 90% of earth • FOOD CHAIN • GrassG. hopperhawk • Grassmousesnake
  23. 23. CATEGORIES OF ECOSYSTEM • GRASSLAND ECOSYSTEM Structure and function of Ecosystems ABIOTIC COMPONENTS BIOTIC COMPONETS Nutrients in the soil includes C,H,N,O,P,S,Water CO2, Nitrates PRODUCERS CONSUMERS DECOMPOSERS Mainly grasses and few forbs and shrubs Pri. Consumers Cow, rabits, sheeps Secondary cosumers Fox birds Ter. Cosumers hawk Microbes like fungi, bacteria
  24. 24. CATEGORIES OF ECOSYSTEM • DESERT ECOSYSTEM • It occupies 17% of land area • Receives annual rainfall below 25cm • Large unoccupied area, poor availability of water • Evaporation rate is high • Less humidity • Continues sunshine temperature is about 380ᴼC day time night 4ᴼC • Vegetation includes shrubs underground corns • Here the animals can conserve water and food for long time
  25. 25. CATEGORIES OF ECOSYSTEM • DESERT ECOSYSTEM ABIOTIC COMPONET BIOTIC Dry soil with fewer rainfall and high temperature. Lack of organic matter in soil PRODUCERS CONSUMERS DECOMPOSERS Shrubs , some grass and few trees P. con. Insects camels S. Con Lizard beetle reptiles T . Con. Red tailed hawk, vultures Thermophilic fungai Bacteria Poor vegetation decomposers are very low
  26. 26. CATEGORIES OF ECOSYSTEM • AQUATIC ECOSYSTEM ( FRESH WATER) • Pond lake ES • Artificial or nature, temporary or permentant • Self sufficient and self regulating • Stagnent • More polluted, due to • limited amount of water • Over utilisation of species
  27. 27. CATEGORIES OF ECOSYSTEM • AQUATIC ECOSYSTEM ( FRESH WATER) Abiotic component Biotic componets Temperature, light, pH, water, organic and inorganic component Producers Consumers Decomposers Rooted plants, floating or suspended plants, phytoplanktons p. con. Animal feeding microphytes, birds feeding phytoplankton Sec. con. Insects, fishes, crabs Ter. Con. Large fishes Micro organisms like fungai, bacteria
  29. 29. What is Biodiversity • Definition • Verity of lives on earth • Include all life forms-fungai, protozoa, bacteria to plants, birds fish and mammal • Variability in living organism from terrestrial marine and aquatic ES and diversity within the species Hierarchical levels I. Genetic diversity II. Species diversity III.Ecosystem diversity
  30. 30. What is Biodiversity • Genetic diversity • Variation of genes within the species • Genes : basic unit of all life • Genes are responsible of both similarities and difference b/w organisms • Within a species there can be slight variations in size, shape, resistance against diseases • To conserve genetic diversity , diff population must b conserved • Degree of conservation assessed from • Diversity within breeding pop. • Within species • Ability to withstand env. condition
  31. 31. Genetic diversity
  32. 32. What is Biodiversity • Species Diversity • Richness of species in an ecosystem • Counting the numbers and chances of species in an ecosystem • Ex; A community in which each species of same number of individual- more diverse • A community in which a particular species of large number of individual- less diverse
  33. 33. What is Biodiversity • Ecosystem diversity • Existence of different ecosystem in a continent • It can be assessed in terms of species diversity • Assessment- evaluation of richness of species and their relative abundance • Landscape diversity • Refer to size of several ecosystems • Refers to their interaction with the land surface
  34. 34. MEASURING B. D. • Alpha diversity • Refers to the number of species in a community Ex; Sahara desert and Amazon tropical rain forest • Beta diversity • Refer to degree to which a community Changes along env. Gradient Ex; Moss community • Gamma diversity • Rate at which additional Species are seen in ES due to Change in geographical condition
  35. 35. MODULE 1 The Multidisciplinary nature of Environmental Science
  36. 36. Introduction • World comprises two components:- • Natural world —Plants, Animals, Soil, Air and water. • Anthropogenic world —Social institutions, mechanical devices buildings created for ourselves (using sciences, technology and political organisations) Definition of Environment Physical, biological, biophysical, topographical and climatological conditions that surround and organisms or group of organisms Environmental Science Is an applied interdisciplinary field concerned with the environment around us Is concerned with social issues:- Environmental policies and law, sustainability, resource economics, urban planning, environmental ethics
  37. 37. Introduction • Environmental science Knowledge of ES need understanding in agriculture, anthropology, genetics… Is a study of interaction among physical chemical biological components
  38. 38. Introduction • Goals of Evs Studies  Reduction of societal consumption of non-renewable fuel resources  Development of alternate low carbon renewable energy resources  Conservation of scarce material resources  Protection of unique ecosystems  Preservation of endangered species  Establishment of Biosphere reserves • Scope Create awareness among the people to know about renewable and non-renewable resources of region Provide knowledge of ecological systems
  39. 39. Introduction • Goals  Reduction of societal consumption of non-renewable fuel resources  Development of alternate low carbon renewable energy resources  Conservation of scarce material resources  Protection of unique ecosystems  Preservation of endangered species  Establishment of Biosphere reserves • Scope Create awareness among the people to know about renewable and non-renewable resources of region Provide knowledge of ecological systems Enables to understand the cause and consequences of natural and man made disasters and pollution and measures to minimize it Enables environmentally literate citizen to make apt judgment and decision for the protection and improvement of earth
  40. 40. Introduction • Scope (continues)  Exposes the problems of over population, health, hygiene and role of art science and technologies to various environmental issues  Study convert theoretical knowledge to practice  It teaches the citizen the need for sustainable utilization of resources • Importance  To study the env. In totality  To understand the Economic value of the nature  To understand the whole of the life process of man  To understand the interdisciplinary approach of this branch  To activate the participation of people in prevention and control of various kinds of pollution  To control the human beings in the use of food, apparels, plastics, fuels, water, paper, electricity
  41. 41. Introduction • Importance (continues)  To understand the environmental issues from local, regional, national, international point of view  To enable the cooperation from regional national and international level on env. Issues  To understand the whole of the life process of man  To understand the Aesthetic and Recreational value of nature  To make the citizen to compete to do scientific work to find the practical sol. to current env problem  To motivate the people in planned usage of resources
  42. 42. NEED OF PUBLIC AWARENESS • Introduction  Enhanced pace of development activities and rapid urbanization-- resulted in stress on natural resources and quality of life  Trend of increasing pollution in various environmental media is evident from the deteriorating air and water quality, higher noise levels, increasing vehicular emission  Realizing the urgent need for arresting the trend, Ministry adopted Policy for Abatement of Environmental Degradation  Urgent need for public awareness about cleaner environment  Education should be given to women and children
  43. 43. NEED OF PUBLIC AWARENESS • How to create awareness…  By forming an Action group and recognised NGOs  By joining local green movement and env. Conservation programmes  By propagating 3R principles  By organizing debates on env. Conservation with the help of educational institution  By arranging tours to National Parks, Santuaries • Institutions on Environment Institution Duties Bombay Natural History Society(1883) It disseminate knowledge of flora and fauna by means of lectures, field trips, literature Center for Environmental Education(1984) It aims to create env. Awareness amon the communities
  44. 44. NEED OF PUBLIC AWARENESS • Institutions on Environment Institution Duties Center for Science and Environment Researches in the field of pollution, forest, wildlife, land and water use Indian Association of Environment Management(1963) It conduct seminars, essay competition and exhibitions related to water pollution
  45. 45. NATURAL RESOURCES • Naturally occurring substances undisturbed by humans • Activities associated with it:- extraction and purification • Natural resources industries:- mining, petroleum extraction, fishing, hunting and forestry • Classifications:- based on by – 1. source of origin, – 2. stage of development, – 3. renewability
  46. 46. NATURAL RESOURCES • Based on Origin:- • Biotic Resources • Abiotic Resources • Based on Stage of development – Potential Resources:- petroleum – Actual Resources:-wood – Reserved Resources:- profitably used – Stock resources:- hydrogen • Based on renewability • Renewable resources • Non-renewable resources:- fossil fuel
  48. 48. FOREST RESOURCES • Functions of forest:-  Habitat of flora and fauna  Balances gaseous cycle:-  Accelerate rainfall  Increase water holding capacity of soil  Maintain soil fertility  Prevent runoff increase the percolation  Provide cool atmosphere
  49. 49. DEFORESTATION Causes :- • Never ending need for timber, firewood and synthetic fibre • Tunnels railways through forest • Population explosion • Hydroelectric project • Overgrazing by cattle • Climate and weather change • Pests destroy forest
  50. 50. FOREST RESOURCES • Effect of Deforestation • Soil erosion • Expansion of desert • Decrease in rainfall • Lose of fertile land • Effect on climate • Lowering of water table • Economic losses • Loss of flora and fauna • Loss of biodiversity • Increase in CO2 • Shortage of fire wood cause serious misery among tribal womenfolk
  51. 51. FOREST RESOURCES • Effect of Mining in Forest • Pollution of surface and ground water resources due to the discharge of mineralized mine water • Air pollution due to release of green house gases ex: CH4 • Subsidence of land near mining area • Drying up of perennial water source • Migration of tribal people
  52. 52. FOREST RESOURCES • Effect of Dams/River Valley projects • Reservoir induces seismicity • Increased incidence of water borne diseases like malaria, filaria • Rehabilitation and resettlement • AFFORESTATION PROGRAMME • Conservation forestry : Re-growth of native vegetation • Commercial forestry:- supply of goods • Production forestry:- • Social forestry • Agro forestry or Urban forestry
  53. 53. FOOD RESOURCES • Food essential component required by the body at all stages of life Sources of food CROP LIVE STOCKS AQUA CULTURE CROPS Fact:- 250000 species of plants / 3000 are agricultural/ 300 grown for food/100 are produced large scale Main crops:- wheat, rice, corn World produces 1.6 million metric tons of wheat LIVE STOCK Includes domesticated animals eg:- cattle goat sheep camel
  54. 54. FOOD RESOURCES AQUA CULTURE Fact:- fish and sea food contribute 70 million metric tons of high quality protein to world’s diet WORLD FOOD PROBLEM 840million people remain chronically hungry in world 300million people in India are poverty stricken 5% 95% 40MILLION 800MILLION 72% 28% 300million in India 500million in other country
  55. 55. FOOD RESOURCES • Food insecurity :- reason :- inequitable distribution of income among the population • FOOD INSUFFICIENCY UNDER NOURISHMENT AND MALNOURISHMENT UNDERNOURISHMENT Lack of sufficient nutrients in available food Disability to move and work FACTS:- 2500cal/day is consumed by the world Reason for undernourishment :- dietary intake is b/w 80%-90% Major victims are children:- mental retardation, stunted growth their dietary intake is <80%
  56. 56. FOOD RESOURCES • Food insecurity :- reason :- inequitable distribution of income among the population • FOOD INSUFFICIENCY UNDER NOURISHMENT AND MALNOURISHMENT MALNOURISHMENT Lack of specific components protein, vitamin in available food Poor countries can’t afford expensive food Death due to Malnourishment is not prominent People are less productive and suffer from brain damage
  57. 57. FOOD RESOURCES • OVERNUTRITION Daily calorie intake of people in DVLPD countries=3500cal/day>>2500 Over weight, high blood pressure, heart attack CHANGES CAUSED BY AGRICULTURE on ENV Agricultural Industry :- oldest and largest Production processing and distribution of food by industry 1ᴼ effect or On site Effect 2ᴼ effect or Off site Effect Classifications :- LOCAL, REGIONAL , GLOBAL changes
  58. 58. FOOD RESOURCES • LOCAL CHANGES Occur at or near the farm site Sedimentation in local river, soil erosion Eutrophication :- fertilizers carried by the sediments Sediments carries toxins REGIONAL CHANGES Large scale effect:- causes deforestation, desertification Sedimentation in major rivers Changes the chemical fertility over a large area GLOBAL CHANGES Attributed to climatic changes
  59. 59. FOOD RESOURCES • EFFECT OF MODERN AGRICULTURE +ve and –ve effect Fertilizers , Pesticides, insecticides Main problems are water logging and salination Problems from:- FERTILIZERS Inorganic component necessary :- N, P, K ca, mg , sulphur +ve Effect:- Easy to store, handle, apply,transport Less smell, lower risk of pathogenic contamination -ve Effect:- Artificial fertilizers cause contamination Excessive level of Nitrates in GW Phosphate deposition cause Eutrophication, threat to water supply
  60. 60. FOOD RESOURCES • EFFECT OF MODERN AGRICULTURE Problems from:- PESTICIDES PESTS:- Insects, bacteria, weeds and birds +ve EFFECTS:- Maximises the crops Reduce post harvest losses Control the diseases and weeds Improve the appearance of crops -ve EFFECTS:- On Non target species Over usage Tendency to get concentrated on food web Misuse and unsafe method of application Creation of new pests
  61. 61. FOOD RESOURCES • EFFECT OF MODERN AGRICULTURE Effect of PESTICIDES on human health Short term :- acute poisoning and illness Long term:- cancer, birth defects, immunological diseases WATER LOGGING Reason:- surface flooding, high water table SALINITY Increased concentration of soluble salt in soil Reason :- intensive agricultural practice poor drainage