environmental science and ecosystem full module

Key environmental problems and its sustainable solutions.

1. 1 Environmental Science - CHY1002 Module-1: Environment and Ecosystem Reference: Benny Joseph; Kaushik and Kaushik; S. Kannappan and Erach Bharucha , Google, wikipedia Key environmental problems, their basic causes and sustainable solutions. IPAT equation. 1 Ecosystem, earth – life support system and ecosystem components 2 ; Food chain, food web, Energy flow in ecosystem; Ecological succession- stages involved, Primary and secondary succession, Hydrarch , mesarch , xerarch; Nutrient, water, carbon, nitrogen, cycles; Effect of human activities on these cycles.

2. Environmental Science:- Environmental science is the study of the environment, its biotic & abiotic component's & their relationship. Wikipedia defines Environmental Sciences: as an interdisciplinary academic field that integrates Physics, Biology and Geography to the study of the environment, and the solution of environmental problems. Environmental science is an interdisciplinary study of how humans interact with the living and non-living parts of their environment. Environmental Engineering:- Environmental Engineering is the application of engineering principles to the protection & enhancement of the quality of the environment and to the enhancement and protection of public health & welfare. Environmental Studies (or) Environmental education:- Environmental studies is the process of educating the people for preserving the quality of the environment.

3. Environment

4. Nature capital ( William Vogt -1948) Natural capital is another term for the stock of renewable and non-renewable resources on earth (e.g. plants, animals, air, water, soils, minerals) that yield a flow of benefits to people. The broad range of services provided by natural capital include food, water, energy, shelter, medicine, and the raw materials we use in the creation of products.

5. 5. Define natural capital, natural resources , and natural services: Natural capital is the natural resources and natural services that keep us and other forms of life alive and support our economies. Natural resources are materials and energy in nature that are essential or useful to humans. These resources are often classified as renewable (such as air, water, soil, plants, and wind) or nonrenewable (such as copper, oil, and coal). Natural services are processes in nature such as purification of air and water, which support life and human economies.

6. 193 countries in the world = 8 billion or 800 crores populations What is the origin of environmental problems?? Key environmental problems:

7. 1804 – 1 billion all over the world 1900 – 2 billion all over the world 2022 – 8 billion all over world Population : the number of same species living and inter-breeding in a particular area Definition of environmental problems : It s any change or disturbance to he environment considered to be undesirable or dangerous. Its also brings down or reduces he capacity of the environment to meet the social and ecological problems

8. Environmental Problems: Pollution Global warming Over population Natural resource depletion Waste disposal Climate change Loss of biodiversity Deforestation Ocean acidification Ozone-layer depletion Acid rain Water pollution Urban sprawl Public health issues Genetic engineering Population – Industrialization & Urbanization – Economic development – Environmental side effects

9. What is an environmentally sustainable society? It means living off the Earth’s natural income without consuming or degrading the natural capital that supplies it.

10. 10 famous environmental activist in India:

11. Ecosystem, earth – life support system and ecosystem components; Food chain, food web, Energy flow in ecosystem Class – 2 (09/23/2022) SJT-G08

12. 38 “An ecosystem is the smallest self-sustaining natural unit consisting of all plants, animals and micro-organisms (biotic factors) in an area functioning together with all of the non-living physical and chemical (abiotic) factors of the environment. It is not an area – It is a natural unit! It can be as small as a pool or as big as an ocean. Ecosystem in other means Those on land Grasslands Forests Desserts Those in water River Pond, lake Ocean Estuary Examples:

13. 39 Abiotic components of an ecosystem All non-living components form the abiotic components The Abiotic (Physical and chemical) factors are: Physical Factors: Sunlight, its intensity and duration -- necessary for photosynthesis Annual rainfall (water) -- all living things require some water to different extent Temperature -- all living things have a range of temperatures in which they can survive; Oxygen -- many living things require oxygen; it is necessary for cellular respiration, others are actually killed by the presence of oxygen (certain anaerobic bacteria) Soil– The type of soil, Its pH, Amount of water it holds, Chemical Factors: Available nutrients, like C, N, P, K, H, O and S, Organic substances present in soil etc determine what type of organism can successfully live in or on the soil;

14. 1 1a Distinguish among producers (autotrophs), consumers (heterotrophs), and decomposers and give an example of each in an ecosystem. Green Sulfur bacteria

15. 51 Decomposers Decomposers, also called recyclers are fungi, bacteria and other microorganisms that decompose organic matter to reusable inorganic form They derive their nutrition by breaking down the complex organic species to simple organic compounds and ultimately into inorganic nutrients

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17. Terrestrial and Marine ecosystem

18. 67 Types of Food Chains Why we have lot of mosquitoes? Especially in city areas

19. 70 Food web “A food web is the interlocking pattern of various food chains of an ecosystem put together”

20. 71 © 2003 John Wiley and Sons Publishers Fig 6.5 Food web of the harp seal.

21. 72 What is the Advantage of Food web over food chain? Suppose there are no food webs but only food chains. In a food chain if one species gets affected (or) becomes extinct, all other species also affected The species lower in the series will increase in number Creates an imbalance But in food web even if one species in the chain is lost, the animals above in the chain survive because of the other chains.

22. 73 They are responsible for the energy flow and nutrient flow in the ecosystem Help maintaining and regulating the population size of different animals and thus, help maintain the ecological balance Eg : Deer controls the extent of growth of grass. Tigers control the number of deer. If deer are not present too much of grass grows and nutrients from the soil are lost. Then no further grass growth. If no grass is present deer cannot survive. Tigers cannot survive If instead, No tiger is present the number of deer increases and they ultimately eat all the grass and cannot survive further after all the grass is lost. Importance of food chains and food webs

23. Why India brought 8 Cheetahs from namibia Google Hires 200 Goats to Munch their Weeds Any correlation between this with Ecosystem????

24. 75 Trophic Structure Each food level is known as trophic level and the amount of living matter at each trophic level at a given time is known as standing crop or standing biomass

25. A. Terrestrial Ecosystem Forest Ecosystem Forest: Collection of biological organisms & non-biological factors. From trees to the bacteria, and the soil type to the micro-climates. Natural forces - wind and fire - shape the forest structure. Characteristics: Types of Forest Tropical forest: Surrounding the equator (India, Africa, Sourth America) Mountain forest: Mountain areas upto 1500 m altitude. Temperate forest: Forests that exist above 1600 m altitude. Alpine forest: High mountain forests that exist above 3000 m altitude. Functions of the Forest ♣ Protects biodiversity. ♣ Maintains climate & rainfall.

26. 2. Grassland Ecosystem Grassland occupies about 19 % of earth’s surface. Dominated by grass along with few trees and shrubs. Characteristics: Average and erratic rainfall. Primary production of food. Functions Traps solar energy and biomass is consumed by producers. Serves as a pool of energy for grassing animals. Prevent soil erosion. Insects living and breeding takes place.

27. 3. Desert Ecosystem Desert constitutes about 17 % in the world. Characteristics Annual precipitation is less than 25 cm. Poor species diversity. Atmosphere is very dry. Contains thorny plants and thick-skinned animals. Functions Rich in nutrients. Storehouse of micro and macronutrients. Place for evolution of adoptive animals like camel.

28. B. Aquatic Ecosystem 1. Pond Ecosystem Pond is a fresh water ecosystem, and is self sufficient & self-regulating. Characteristics Stagnant fresh water . May be temporary, only seasonal. More polluted due to over utilization by community. Functions Serves as resource for small water requirements. Contains small algae, plants and animals. Place for human activity like drinking, swimming, washing cloths. Structure of Pond Ecosystem

29. 2. Lake Ecosystem Bigger fresh water body than ponds. Characteristics Shallow fresh water. Permanent and large water resource. Helps in irrigation and village community life. Self-sufficient ecosystem. Functions Reservoir for large fresh water. Stores water during rainy season and latter used for irrigation. Used for transport of goods and people in the offshore.

30. 3. Stream Ecosystem Moving water systems & fresh water ecosystem. Characteristics: Dynamic fresh water ecosystem. Have high self-purification capacity. Might be dry during summer. Functions Provides fresh water for large community of people living near-by. Used for irrigation of smaller land areas.

31. 4. River Ecosystem Large dynamic fresh water stream originating from mountains. Drain down in sea or large lake. Characteristics Free-flowing fresh water system. Flows through longer area and length, and provides support to surrounding areas. Change the place of flow and also deposits large amount of nutrients. Functions Serves as fresh water resource for large community of people & animals. High self-purification capability. Irrigation for large area and length. Used to transport goods and people.

32. 5. Marine Ecosystem Oceans in the world covers about 71 % of the earth’s surface (Atlantic, Pacific, Indian, Artic & Antarctic oceans). Represents a very large saline ecosystem. Characteristics It is a saline water ecosystem. Occupies a large surface area. Vessels like ships & submarines can sail. It is rich in biodiversity. Functions Serves food for many marine and terrestrial species. Provides many products like drugs, stones, crude oil, etc. Reservoir for NaCl and many other minerals. Plays a major role in climate change and biogeochemical cycle Abiotic components Biotic components Producers Consumers Decomposers About 27 % of 0.5M NaCl, remaining Mg, Ca & K salts, temperature, light. Diatoms, microscopic algae. 1°- Crustaceans, mollusks, fish. 2° - Herrings, shad. 3°- Cod, Haddocks. Fungi, bacteria, etc. Structure of Marine Ecosystem

33. 85

34. 86 Energy Flow in an Ecosystem

35. 87 Energy flow -Thermodynamics 1 st Law: Energy is neither created or destroyed 2 nd Law: When energy is converted to one form to another, a part of it is dissipated energy flow in an ecosystem follows the laws of thermodynamics

36. Energy Flow Models Energy flows through various trophic levels in an ecosystem: Universal Energy Flow Model Single Channel Energy Flow Model, and Double Channel Or Y-shaped Energy Flow Model

37. Universal Energy Flow Model Applicable to all living components. There is gradual loss of energy at every trophic level. This loss of energy is mainly Energy “Not Utilized” ( NU ) (being lazy) Other energy losses: locomotion, excretion, respiration ( R ). Rest of the energy (growth) is used for Production ( P ).

38. Single-Channel Energy Flow Model Energy flows in one-way direction; Energy captured by autotrophs does not revert back to solar input but passes to herbivores which does not go back to autotrophs but passes to consumers. Entire system would collapse if primary source of energy were cut off. energy not utilized ( NU ) and not assimilated ( NA ). Both stored energy and flowing energy decrease while moving through a food chain.

39. Double channelled (Y shaped) Energy Flow Model Y- shaped model shows a common boundary, light and heat flow as well as import, export and storage of organic matter. In this model, the passage of energy happens via two food chains. Decomposers are placed in separate box to partially separate the grazing food chain and detritus food chain . In terms of energy levels, decomposers are a mixed group. In marine ecosystem, very little primary production is passed to the detritus compartment, whereas in forest ecosystem the detritus food chain is more important.

40. Y- shaped energy flow is more realistic and practical than the single channel energy flow model because: • It conforms to the basic stratified structure of ecosystems • It separates the two chains i.e. grazing & detritus food chain • Micro-consumers ( bacteria & fungi) and the macro-consumers (animals) differ greatly in size.

41. 94 Ecological Pyramid Types of Ecological Pyramid: Pyramid of Energy Pyramid of numbers Pyramid of Biomass Definition: “Graphic representation of trophic structure and function of an ecosystem, starting with producers at the base and successive trophic levels forming the apex is known as ecological pyramid” The pyramid may be constructed with respect to energy flow, number of species at each trophic level or with respect to the biomass of all species in a particular trophic level

42. 95 Ecological Pyramid Types of Ecological Pyramid: Pyramid of Energy Pyramid of numbers Pyramid of Biomass Definition: “Graphic representation of trophic structure and function of an ecosystem, starting with producers at the base and successive trophic levels forming the apex is known as ecological pyramid” The pyramid may be constructed with respect to energy flow, number of species at each trophic level or with respect to the biomass of all species in a particular trophic level

43. 99 1. Pyramid of Energy The greatest amount of energy is found at the base of the pyramid. The least amount of energy is found at top of the pyramid. Source: corpuschristiisd.org/user_files/91702/Ecosystem.ppt

44. 100 Pyramids of numbers - Shape depends on Type of ecosystem -Upright for grass and forest ecosystems Pyramid of energy is always upright Pyramids of Biomass -upright or inverted depends On food chain and ecosystem

45. 101 2. Pyramid of numbers Pyramid of Numbers: It represents the number of individual organisms at each tropic level. We may have upright or inverted pyramid.

46. 102 Biomass Energy is sometimes considered in terms of biomass, the mass of all the organisms and organic material in an area. (Only dry mass in the species is considered as biomass) There is more biomass at the trophic level of producers and fewer at the trophic level of tertiary consumers . (There are more plants on Earth than there are animals.) Bio=life Mass=weight Bio + Mass = Weight of living things within an ecosystem.

47. 103 Ecological Pyramid Shapes of ecological pyramids: The flow of energy decreases as we go from one trophic level to another and the energy pyramid is always upright The shape of ‘Pyramid of numbers’ depends on the type of ecosystem and food chain. It is upright for grass and forest systems and inverted for parasitic food chain The ‘pyramid of biomass’ is either upright or inverted. Inverted for pond ecosystems and upright for grassland and forest ecosystems Grass ecosystem Aquatic ecosystem

48. 104 Functions and Functional attributes of an ecosystem

49. 105 Ecological succession It is a gradual change, and it is the organisms present which bring about this change. occurs in stages, called seral stages, that can be recognized by the collection of species that dominate at that point in the succession. begins when an area is made partially or completely devoid of vegetation because of a disturbance . Some common mechanisms of disturbance are fires, wind storms, volcanic eruptions, logging, climate change, severe flooding, disease, and pest infestation. stops when species composition no longer changes with time, and this community is called the a climax community. The gradual and continuous replacement of plant and animal species by other species until eventually the community, as a whole, is replaced by another type of community. Ecosystem – A dynamic system – so there will be change in Structure and Function

50. 106 Ecological Succession is defined as an orderly process of changes in the community structure and function with time mediated through modifications in the physical environment and ultimately culminating in a stabilized ecosystem known as climax. Definition :

51. 107 Primary succession vs. secondary succession: Primary succession - occurs on an area of newly exposed rock or sand or lava or any area that has not been occupied previously by a living (biotic) community. Secondary succession - takes place where a community has been removed , e.g., in a plowed field or a clear­-cut forest Secondary succession

52. 108 Stages in Ecological succession Nudation Invasion Competition and coaction Reaction Stabilization

53. 109 Stages in ecological succession 1. Nudation : Development of bare area caused by land slides, volcanic eruptions, forest fires etc

54. 110 Stages in ecological succession 2. Invasion: Involves Establishment of one or two species on bare area. These first species arrived are called Pioneer species They do not require soil. . Ex: Lichens

55. 111 Stages in ecological succession Soil starts to form as lichens and the forces of weather and erosion help break down rocks into smaller pieces When lichens die, they add humus This helps in growing small plants

56. 112 Stages in ecological succession As the plants die they add more humus to soil Now bigger plants and trees can grow.

57. 113 Invasion:

58. 114 3.Competition and coaction: As the number of individual species grow , there is competition for space, water, nutrients etc. They influence each other, called coaction 4. Reaction: When vegetation grows, living organisms move in and influence the environment. Some species sustain , some are lost in the process Strong influence on the environment.

59. 115 5. Stabilization One or more communities will finally succeed in stabilizing. This community is called climax community.

60. The elements and compounds that make up nutrients move continually through air, water, soil, rock, and living organisms within ecosystems, as well as in the biosphere in cycles called biogeochemical cycles (literally, life-earth-chemical cycles), or nutrient cycles .

61. What are Nutrient or Biogeochemical Cycles? Discuss the nutrient cycling with a neat diagram. Describe nutrient cycling and explain why it is important. Nutrient or Biogeochemical Cycles: The cyclic flow of nutrients between the biotic ( living organisms within ecosystems, as well as in the biosphere) and abiotic ( air, water, soil, rock ) components. Nutrient cycles connect past, present and future forms of life. Reservoirs: As nutrients move through their biogeochemical cycles, they may accumulate in certain portions of the cycles and remain there for different periods of time. These temporary storage sites such as the atmosphere, the oceans and other water bodies of water and underground deposits are called reservoirs. Cycle Types: Hydrologic (water), carbon, nitrogen, phosphorous and sulfur cycles.

62. 1. Water cycle The hydrological/water cycle collects, purifies and distributes the earth’s fixed supply of water. •Powered by energy from the sun and involves 3 major processes Evaporation: Incoming solar energy causes evaporation of water from the Earth’s oceans, lakes, rivers and soil. Precipitation: Gravity draws the water back to the earth’s surface as precipitation (rain, snow) Transpiration: 90 % of the water that is precipitated evaporates back into the atmosphere from the surfaces of plants (through a process called transpiration) and from the soil.

63. 2. Carbon Cycle Carbon is the basic building block of the carbohydrates, fats, proteins, DNA and other organic compounds necessary for life. The carbon cycle is based on CO 2 gas (0.039 % of volume of the earth’s atmosphere), and it is dissolved in water. CO 2 is a key component of the atmosphere’s thermostat. If the carbon cycle removes too much CO 2 from the atmosphere, the atmosphere will cool. If the carbon cycle generates too much CO 2 , the atmosphere will get warmer.

64. Marine sediments are the earth’s largest store of carbon - buried deposits of dead plant matter and bacteria are compressed between layers of sediment, where high pressure and heat convert them to carbon-containing fossil fuels such as coal, oil, and natural gas – not released to the atmosphere as CO 2 for recycling until these fuels are extracted and burned, or until long-term geological processes expose these deposits to air.

65. In only a few hundred years, we have extracted and burned huge quantities of fossil fuels that took millions of years to form. Thus, on a human time scale, fossil fuels are non-renewable resources. Burning fossil fuels and wood releases more CO 2 than natural processes Deforestation reduces the amount of vegetation to remove CO 2 - Put more CO 2 in the atmosphere Increased concentrations of atmospheric CO 2 and other gases are very likely to warm the atmosphere by enhancing the planet’s natural greenhouse effect, and thus to change the earth’s climate – Global Warming 45 Effect of human on carbon cycle

66. 3. Nitrogen cycle N 2 gas makes up 78 % volume of the atmosphere. Nitrogen - is a crucial component of proteins, many vitamins and nucleic acids such as DNA. N 2 cannot be absorbed and used directly as a nutrient by multicellular plants/animals. Two natural processes convert/fix N 2 into nutrients which can be used by plants and animals. 1. Electrical discharge/lightning taking place in the atmosphere. 2. In aquatic systems - in soil, and in the roots of some plants, nitrogen fixing bacteria completes this conversion as part of nitrogen cycle. In Earth – Organic matters (amides) - NO 3 (leaching, denirtification , Ammonia) Atmosphere, microbes Ammonia – Plants (Mineral acids) also different pathways – In dry condition act as poison

67. nitrogen fixation, nitrogen assimilation, ammonification, nitrification, denitrification .

68. The bacteria use some of the NH 3 they produce as a nutrient and excrete the rest into the soil or water. – Some of the NH 3 is converted to ammonium ions (NH 4 + ) that plants can use as a nutrient. Plants and animals return nitrogen –rich organic compounds to the environments through wastes and cast-off particles of tissues such as leaves, skin or hair and through their bodies when they die. and are decomposed or eaten by detritus feeders. Nitrification : Ammonia not taken up by plants may undergo nitrification. In this process, specialized soil bacteria convert most of the NH 3 and NH 4 + in soil to nitrate ions (NO 3 ), which are easily taken up by the roots of plants. The plants then use these forms of nitrogen to produce vitamins. Nitrogen Cycle

69. Nitrogen Cycle In ammonification , vast armies of specialized decomposer bacteria convert this detritus into simpler nitrogen-containing inorganic compounds such as ammonia (NH 3 ) and water-soluble salts containing ammonium ions (NH + ). In denitrification , specialized bacteria in waterlogged soil and in the bottom sediments of lakes, oceans, swamps, and bogs convert NH 3 and ( NH + ) back into nitrate ions, and then into nitrogen gas (N 2 ) and nitrous oxide gas (N 2 O) . These gases are released to the atmosphere to begin the nitrogen cycle again.

70. Explain with a help of a diagram and the effect of human activities on nitrogen cycle. Human activities have more than doubled the annual release of N 2 from the land into the rest of the environment through the greatly increased use of inorganic fertilizers (straight type: ammonium nitrate (NH 4 NO 3 ) and binary type: diammonium phosphate  (DAP, (NH 4 ) 2 HPO 4 )) to grow crops.