The document discusses various topics related to environmental science including energy flow in ecosystems, food chains and webs, ecological pyramids, succession, biogeochemical cycles, categories of ecosystems like grasslands and aquatic ecosystems, and biodiversity. It also covers natural resources like forests and food resources, and issues related to deforestation, mining in forests, dams and river valley projects, and afforestation programs.

1. ENVIRONMENTAL SCIENCE

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. • Energy entering pathways are 2.
– By the primary producers(Auto trophs)
– By the wind current or air convection through soil
ENERGY FLOW

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. FOOD CHAIN
• Types
– Grazing food chain
– Detritus food chain

6. FOOD CHAIN

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. FOOD WEB
• Series of interconnected food chains
terrestrial food web

9. FOOD WEB
• Linear arrangements of food chain is difficult

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. 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. 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. 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. 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. 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. 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

17. MAJOR CYCLES IN ECOSYSTEM
• WATER CYCLES

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

19. MAJOR CYCLES IN ECOSYSTEM
• CARBON CYCLE
• OXYGEN CYCLE

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

21. MAJOR CYCLES IN ECOSYSTEM
• NITROGEN CYCLE

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. 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. 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. 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. 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. 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. BIODIVERSITY

30. 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

31. 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

32. Genetic diversity

33. 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

34. 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

35. 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

36. MODULE 1
The Multidisciplinary nature of
Environmental Science

37. 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

38. Introduction
• Environmental science
Knowledge of ES need understanding in
agriculture, anthropology, genetics…
Is a study of interaction among physical chemical biological components

39. 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

41. 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

42. 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

43. 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

44. 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

45. 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

46. 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

47. 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

48. 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

49. NATURAL RESOURCES
• FOREST RESOURCES

50. 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

51. 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

52. 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

53. 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

54. 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

55. 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

56. 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

57. 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%

58. 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

59. 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

60. 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

61. 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

62. 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

63. 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