environmental science
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ENVIRONMENTAL SCIENCE
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
• Energy entering pathways are 2.– By the primary producers(Auto trophs)
– By the wind current or air convection through soil
ENERGY FLOW
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
FOOD CHAIN• Types – Grazing food chain– Detritus food chain
FOOD CHAIN
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 foodEg: Wheat->Man
: Algea->insects->fish->man
FOOD WEB• Series of interconnected food chains
terrestrial food web
FOOD WEB• Linear arrangements of food chain is difficult
ECOLOGICAL PYRAMIDS• Graphical representation of trophic structure of ES• Relationship b/w energy • 3 types– Pyramid of NUMBERS– Pyramid of BIOMASS– Pyramid of ENERGY
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
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
ECOLOGICAL SUCCESSION• Process through which the ES tends to change over a
period of time• Causes of ecological succession– Initial causeClimatic causes: wind, fire, erosionBiotic causes: activities of living creatures– Ecesis causeMigration, competition, aggregation, – Stabilisation causesStabilisation of communityReason:climate
ECOLOGICAL SUCCESSION• Types of succession– Primary and secondary– Primary successionIt is the initial development of ecosystemCommunity occupies on an unoccupied siteEx: forest on a new hardened lava formForest on a retreating glacier
- Secondary successionRe-establishment of ecosystemIn this remnants of previous biological community, organic
matters of previous community
ECOLOGICAL SUCCESSION• Characteristics
It is unidirectional in natureModifies the physical envIt is predictableIt 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
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
MAJOR CYCLES IN ECOSYSTEM• WATER CYCLES
MAJOR CYCLES IN ECOSYSTEM• CARBON CYCLE• Carbon included in ABIOTIC and BIOTIC parts• Building block• Plants takes CO2 + Light fixationcarbohydrates • Plants gives out O2• Hetrotrophs gives out CO2
• OXYGEN CYCLE• It is a part of Carbon cycle
MAJOR CYCLES IN ECOSYSTEM• CARBON CYCLE
• OXYGEN CYCLE
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
MAJOR CYCLES IN ECOSYSTEM• NITROGEN CYCLE
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• GrassG. hopperhawk• Grassmousesnake
CATEGORIES OF ECOSYSTEM • GRASSLAND ECOSYSTEM
Structure and function of EcosystemsABIOTIC 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. ConsumersCow, rabits, sheeps
Secondary cosumersFox birds
Ter. Cosumershawk
Microbes like fungi, bacteria
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
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. ConLizard beetle reptiles
T . Con.Red tailed hawk, vultures
Thermophilic fungaiBacteria
Poor vegetation decomposers are very low
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
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
BIODIVERSITY
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 speciesHierarchical levelsI. Genetic diversityII. Species diversityIII.Ecosystem diversity
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
Genetic diversity
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
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
MEASURING B. D.• Alpha diversity• Refers to the number of species in a communityEx; Sahara desert and Amazon tropical rain forest• Beta diversity• Refer to degree to which a communityChanges along env. GradientEx; Moss community• Gamma diversity• Rate at which additionalSpecies are seen in ES due to Change in geographical condition
MODULE 1
The Multidisciplinary nature of Environmental Science
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 EnvironmentPhysical, biological, biophysical, topographical and climatological
conditions that surround and organisms or group of organisms
Environmental ScienceIs an applied interdisciplinary field concerned with the environment
around usIs concerned with social issues:- Environmental policies and law,
sustainability, resource economics, urban planning, environmental ethics
Introduction • Environmental science
Knowledge of ES need understanding in agriculture, anthropology, genetics…
Is a study of interaction among physical chemical biological components
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
• ScopeCreate awareness among the people to know about renewable and non-renewable resources of regionProvide knowledge of ecological systems
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
• ScopeCreate awareness among the people to know about renewable and non-renewable resources of regionProvide knowledge of ecological systemsEnables to understand the cause and consequences of natural and man made disasters and pollution and measures to minimize itEnables environmentally literate citizen to make apt judgment and decision for the protection and improvement of earth
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
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
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
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 EnvironmentInstitution 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
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
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
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
NATURAL RESOURCES• FOREST RESOURCES
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
DEFORESTATIONCauses :-• 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
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
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
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
FOOD RESOURCES• Food essential component required by the body at all stages of lifeSources of food
CROPLIVE STOCKSAQUA CULTURE
CROPSFact:- 250000 species of plants / 3000 are agricultural/ 300 grown for food/100 are produced large scale
Main crops:- wheat, rice, cornWorld produces 1.6 million metric tons of wheat
LIVE STOCKIncludes domesticated animals eg:- cattle goat sheep camel
FOOD RESOURCESAQUA CULTURE
Fact:- fish and sea food contribute 70 million metric tons of high quality protein to world’s diet
WORLD FOOD PROBLEM840million people remain chronically hungry in world300million people in India are poverty stricken
5%
95%
40MILLION 800MILLION
72%
28%
300million in India500million in other country
FOOD RESOURCES• Food insecurity :- reason :- inequitable distribution of income
among the population• FOOD INSUFFICIENCYUNDER NOURISHMENT AND MALNOURISHMENT
UNDERNOURISHMENTLack of sufficient nutrients in available foodDisability to move and work
FACTS:- 2500cal/day is consumed by the worldReason for undernourishment :- dietary intake is b/w 80%-90%Major victims are children:- mental retardation, stunted growth their
dietary intake is <80%
FOOD RESOURCES• Food insecurity :- reason :- inequitable distribution of income
among the population• FOOD INSUFFICIENCYUNDER NOURISHMENT AND MALNOURISHMENT
MALNOURISHMENTLack of specific components protein, vitamin in available foodPoor countries can’t afford expensive foodDeath due to Malnourishment is not prominentPeople are less productive and suffer from brain damage
FOOD RESOURCES• OVERNUTRITIONDaily calorie intake of people in DVLPD countries=3500cal/day>>2500Over weight, high blood pressure, heart attack
CHANGES CAUSED BY AGRICULTURE on ENVAgricultural Industry :- oldest and largestProduction processing and distribution of food by industry 1ᴼ effect or On site Effect2ᴼ effect or Off site Effect
Classifications :- LOCAL, REGIONAL , GLOBAL changes
FOOD RESOURCES• LOCAL CHANGESOccur at or near the farm siteSedimentation in local river, soil erosionEutrophication :- fertilizers carried by the sedimentsSediments carries toxins REGIONAL CHANGES Large scale effect:- causes deforestation, desertificationSedimentation in major riversChanges the chemical fertility over a large area
GLOBAL CHANGESAttributed to climatic changes
FOOD RESOURCES• EFFECT OF MODERN AGRICULTURE+ve and –ve effect Fertilizers , Pesticides, insecticides Main problems are water logging and salinationProblems from:- FERTILIZERS
Inorganic component necessary :- N, P, K ca, mg , sulphur+ve Effect:-
Easy to store, handle, apply,transportLess smell, lower risk of pathogenic contamination
-ve Effect:-Artificial fertilizers cause contaminationExcessive level of Nitrates in GWPhosphate deposition cause Eutrophication, threat to water supply
FOOD RESOURCES• EFFECT OF MODERN AGRICULTUREProblems from:- PESTICIDES
PESTS:- Insects, bacteria, weeds and birds+ve EFFECTS:-
Maximises the cropsReduce post harvest lossesControl the diseases and weedsImprove the appearance of crops
-ve EFFECTS:-On Non target speciesOver usageTendency to get concentrated on food webMisuse and unsafe method of applicationCreation of new pests
FOOD RESOURCES• EFFECT OF MODERN AGRICULTUREEffect of PESTICIDES on human health
Short term :- acute poisoning and illnessLong term:- cancer, birth defects, immunological diseases
WATER LOGGINGReason:- surface flooding, high water table
SALINITYIncreased concentration of soluble salt in soilReason :- intensive agricultural practice
poor drainage
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