Environment notes from NIOS
- Evolution of human - Australopithecines --> Homo habilis --> Homo erectus
- Human appeared on earth at around 2ooo million years ago
- Homo erectus learned fire
- around 12000 years ago learned to cultivate
- around 5000 years ago invented wheel
- dog is first domesticated animal
humans have spoilt environment by 1. excessive use of resources and 2. by polluting environment
- Eutrophication of a water body occurs when plant nutrients such as nitrates and phosphates are released by the action of aerobic bacteria on organic wastes entering a water body . These nutrients promote growth of algae (algal bloom). Algae consume all the oxygen and aquatic organism die due to lack of oxygen.
- Collapse of marine fishery : due to global warming animals have permanently moved to cooler northern regions. Smaller fish are able to move faster to cooler areas away and the elevated temperature is taking its toll on larger fish
- Ecology may be defined as the scientific study of the relationship of living organisms with each other and with their environment.It not only deals with the study of the relationship of individual organisms with their environment, but also with the study of populations, communities, ecosystems, biomes, and biosphere as a whole.
- Habitat is the physical environment in which an organism lives. Structural components of Habitat are (1) space (2) food (3) water (4) and cover or shelter. There are four major habitats-(1) Terrestrial(2) Freshwater(3) Estuarine(Where rivers meet the ocean) and (4) Ocean.
- NICHE : functional characteristics of a species in its habitat is referred to as “ niche”. Different species occupy the same habitat but they perform different functions. No two species in a habitat can have the same niche or they will compete with one another until one is displaced. EG. different species of insects or pests of the same plant can co-exist as long as they feed on different parts of the same plant. Important resources in the niches of animals are food and shelter while in case of plants, they are moisture and nutrients.
- Adaptation : is the appearance or behaviour or structure or mode of life of an organism that allows it to survive in a particular environment
- Species : is a group of similar populations of organisms whose members are capable of interbreeding, and to produce fertile of ofspring (children)
- Variation : Difference in colour of skin, type of hair; curly or straight, Variations are produced as a result of chance mutation. Competition and natural selection determines as to which variation will succeed and survive.Variations are heritable.
- Mutation : causes new genes to arise in a population
- Natural selection is selection among variations i.e. genes that help the organism to adopt to its environment. species comprises of many populations when isolated due to some geographic barrier and Mutations occur randomly in isolated populations giving rise to new variation After a long period of time, the sub-populations become very different.
- Population is defined as a group of freely interbreeding individuals. The characteristics of any population depends on: i) density of the population, (ii) natality (birth rate), (iii) mortality (death rate), (iv) dispersal, v) biotic potential (vi) age distribution (vii) dispersion and (viii) growth form.
- ‘J’ shaped growth curve is called density independent growth. It is typical of the species which reproduce rapidly and which are greatly affected by seasonally fluctuating environmental factors like forest fire,change in seasons etc. After reaching a peak there is a sudden crash or decline due to environmental or other factors. eg insect populations.
- Community is collection of populations of different kinds of organisms living together. The characteristic pattern of the community is the roles played by its various populations; range of its various populations; • the type of area that is inhabited by the populations of the community; • the diversity of species in the community; • the interactions between various populations of the community inhabiting the area.In a community only those plants and animals survive which are adapted to a particular environment. A crop communities are relatively simple and consists of only one species. Man made communities are very unstable and require great deal of care. Stratification of a community refers to the vertical layers of the vegetation eg. Ground layer of mosses, Short shrub, short trees, tall trees etc. Important attribute of a community is its species diversity, however, there may be seasonal variation in species composition.
- Species diversity influences the stability of the community. Communities with high species diversity have been found to be comparatively more stable. diversity is calculated both by the number of species (richness) and the relative abundance of each species (evenness). Relative abundance is measure of relative proportion of different species occurring in a community. The greater the number of species and more even their distribution the greater is the species diversity.
- Communities are dynamic in nature and change over a period of time. Plant and animal species in an area are replaced or changed into another over a period of time is known as ecological succession. There are two types of successions (i) Primary succession and (ii) Secondary succession. Primary succession takes place an over a bare or unoccupied areas such as rocks. plants that invade first are called pioneer species. They show high growth rate but short life span, gets replaced by another community. The terminal (final) stage of succession forms the community which is called as climax community.Which is stable, mature, more complex and long lasting. Secondary succession occur when the existing natural vegetation that constitutes a community is removed, disturbed or destroyed by a natural event like hurricane or forest fire or by human related events. Secondary succession is relatively fast.
Place Name & grassland
- - North America Prairies
- - Eurasia (Europe and Asia) Steppes
- - Africa Savanna
- - South America Pampas
- - India Grassland, Savanna
Ecotone is a zone of junction between two or more diverse ecosystems e.g. the mangrove forests. They represent an ecotone between marine and terrestrial ecosystem.Some more examples of ecotone are – grassland, estuary and river bank
Type of Association between two Species
Due to the connected nature of ecosystems, species may affect each other through intermediaries such as shared resources or common enemies.
- -Amensalism: negative association between two species. One harms or restricts the other species without itself being adversely affected or harmed by the presence of the other species eg those who produce antibiotics.
- -Predation: In this type of interaction predator captures, kills and eats an animal of another species called the prey. The predator naturally benefits from this relationship;
- -Parasitism: In this type of interaction, one species is harmed and the other benefits.The parasite is benefited and the host is harmed. Plants like dodder plant (Cuscuta)
- -Competition: This is an interaction between two populations in which both species are harmed to some extent.
- -Commensalism: One of the species benefits while the other is neither harmed nor benefited. Some species obtain the benefit of shelter or transport from another species. For example sucker fish, remora often attaches to a shark. Epiphytes live on the surface of other plants like ferns, mosses and orchids and use the surface of trees for support and for obtaining sunlight and moisture. The tree gets no benefit from this relationship nor are they harmed.
- -Mutualism: This is a close association between two species in which both the species benefit. For example of protocorporation the sea anemone, a cnidarian gets attached to the shell of hermit crabs for benefit of transport and obtaining new food while the anemone provides camouflage and protection by means of its stinging cells to the hermit crab. Species can no longer live without each other as they depend totally on each other to survive are called symbiosis. eg Termites and their intestinal flagellates, pollination of flowers where flowering plants are cross pollinated by the bees which benefit by getting nectar from the plants and both cannot survive without the other
- -Neutralism: relationship between two species which do interact but do not affect each other. True neutralism is extremely unlikely
Ecological pyramids are the graphic representations of trophic levels in an ecosystem. They are pyramidal in shape and they are of three types: The producers make the base of the pyramid and the subsequent tiers of the pyramid represent herbivore, carnivore and top carnivore levels.
- - Pyramid of number:This represents the number of organisms at each trophic level. For example in a grassland the number of grasses is more than the number of herbivores
- - Pyramid of biomass:This represents the total standing crop biomass at each trophic level. S tanding cr op biomassis the amount of the living matter at any given time.expressed as gm/unit area or kilo cal/unit area. In most of the terrestrial ecosystems the pyramid of biomass is upright. However , in case of aquatic ecosystems the pyramid of biomass may be inverted e.g. in a pond phytoplankton are the main producers, they have very short life cycles and a rapid turn over rate (i.e. they are rapidly replaced by new plants). Therefore, their total biomass at any given time is less than the biomass of herbivores supported by them
- - Pyramid of energy:This pyramid represents the total amount of energy at each trophic level.
Human modified ecosystems
Some examples of human modified ecosystems are: (1) Agro-ecosystems (2) Plantation forests (3) Urban ecosystems (4) Rural ecosystems (5) Aquaculture (6) Industrial areas (7) Laboratory cultures
Characteristics of human modified ecosystems
- - (1) Highly simplified.
- - (2) Species diversity is very low .
- - (3) Food chains are simple and small.
- - (4) Depend on human (anthropogenic) support for survival; need for fossil fuel energy ,fertilizers, irrigation etc.
- - (5) Attract large number of weeds.
- - (6) More susceptible to epidemic diseases.
- - (7) Suffer from soil erosion.
- - (8) Highly unstable.
urban settlements–push and pull factors
- Pull factors
- - search of better opportunities, apart from agriculture and cottage industries for crafts, villages do not offer opportunities
- - better life style
- - overcome poverty - Poverty is rampant in most of the villages
- - Continuous trade and economic expansion
- Push Factors
- - Overpopulation
- - Religious/political persecution
- - Slavery/bonded labour
- - discrimination
- - Natural hazards and climate change
- - Fragmentation of family owned land
Characteristics of urban communities
- - Freedom from social control
- - Voluntary association
- - Individualism
- - Social mobility
- - Availability of facilities - Diagnostic clinics, legal services, banks, commercial centres
Characteristics of rural communities
- - village habitations comprised of an enlarged primary group
- - Simple living:God-fearing and tradition bound villagers and compact organization
- - Agriculture forms the dominant occupation
- - Joint family system
- - Social stratification based on castes
- - Jajmani system
- - follow Rural calendar
- - Poverty and illiteracy
- - Averse to mobility and social change: Orthodoxy , illiteracy , superstitions and fear
Cause of degradation
- - rapid growth in population
- - developmental activities
- - shrinkage of agricultural land
- - Modern agricultural technology - leaves no time for soil to revive through the natural processes.
Forests are ecological as well as a socio-economic resource. Approximately 1/3 rd of the earth’ s total land area is covered by forests. it provide habitat for wildlife, resources such as timber , fire wood, drugs etc. and aesthetic environment. Indirectly , the forests benefit people by protecting watersheds from soil erosion, keeping rivers and reservoirs free of silt, and facilitate the rechar ging of groundwater . Forest plays an important role in the cycling of carbon, water , nitrogen and other elements. Forests may be subdivided into natural forests and plantations or man made forests.
Main functions of the forests
- - Productive functions : Production of various types ofwood, fruits and a wide range of compounds such as resins, alkaloids, essential oil, latex and pharmaceutical substances. Timber accounts for 25% of all photosynthetic materials produced on the earth and about half of the total biomass produced by a forest. About 40% of all the drugs used throughout the world have active ingredients extracted from plants and animals.
- - Protective functions : Provides habitats for various organisms conservation of soil and water, prevention of drought, shelter against wind, cold, radiation, noise, sounds, smells and sights.
- - Regulative functions : Absorption, storage and release of gases (most importantly carbon dioxide and oxygen), water, minerals, elements and radiant energy. All such functions improve the atmospheric and temperature conditions and enhances the economic and environmental value of the land .Forests also effectively regulate floods and drought and all the biogeochemical cycles. Absorption, storage and release of gases (most importantly carbon dioxide and oxygen), water, minerals, elements and radiant energy. All such functions improve the atmospheric and temperature conditions and enhances the economic and environmental value of the land .Forests also effectively regulate floods and drought and all the biogeochemical cycles.
Deforestation is a broad term. It includes lopping, felling, and removal of forest litter , browsing, grazing and trampling of seedlings. can also be defined as the removal or damage of vegetation in a forest to the extent that it no longer supports its natural flora and fauna. Forest cover of india is about 22.7%only instead of 33%.
The main causes of deforestation are:
- - agriculture;
- - shifting cultivation;
- - demand for firewood : Almost 44% of the total global wood produced fulfils the fuel requirements of the world
- - demand of wood for industry and commercial purposes;
- - urbanization and developmental projects;
- - other causes.
Tribes and forest : About 4% the world’s population lives in special territories .These indigenous or tribal people have claims on a particular place; they have cultural, spiritual and economic ties with the particular area and in most cases they have ability to manage the area and sustain it. , the tribal people knew the agricultural practices which were ecologically sound. Grow different kinds of food and fibre crops simultaneously on the same plots and keep the land productive for several years
Deforestation affects both physical and biological components of the environment:
- - Soil erosion and flash flood : landslides, flood, washing of top soil
- - Climatic change
- - Loss of biodiversity
- lion –tailed monkey from rain forests and Sholas of south India
- Great Indian Bustard (Ardeotis nigriceps)
- clouded leopard (Neofelis nebulosa) was sold illegally in Kashmir markets
- snow leopard (Leo uncia) hunted for its thick beautiful fur .
- Pea-fowl (MORE), being a national bird, is well protected by people.
desertification: destruction of the biological potential of the land which can ultimately lead to desert like conditions. climate is dry , restoration is very slow, Caused due to : excessive felling of trees, high wind velocity , low precipitation, increasing aridity and extremes of temperatures Causes of land degradation
- - Deforestation
- - Overgrazing– About 20% of the world’s pasture and range lands have been damaged
- - Fuel wood consumption: Wood fuel is the primary source of energy in many developing regions
- - Agricultural mismanagement– Loss of soil due to water erosion, Soil salinization, water logging, chemical degradation
- - Industrialization and urbanization, road construction, mining and industry
About 76.15% of the total Indian desert area has resulted from manmade desertification process. Another 19.5% of the total area is subjected to medium or slight desertification. This area is concentrated mostly along the eastern Rajasthan in the north-east to south-west zone parallel to the foothills of Aravalis.
Other pollutants : Tetraethyl lead, Oxides of iron, aluminum, manganese, magnesium, zinc
Prevention and control of air pollution
- - proper ventilation for disinfectants, fumigants, volatile organic compounds used in houses and buildings
- - Use of cleaner fuels such as biogas, kerosene, smokeless chullahs
- - species of trees such as baval (Acacia nilotica) which are least smoky should be planted and used. Charcoal is a comparatively cleaner fuel
Prevention and control of industrial pollution
- - use of cleaner fuels
- - employing environment friendly industrial processes
- - installing devices which reduce release of pollutants. Devices like filters, electrostatic precipitators, inertial collectors, scrubbers, gravel bed filters or dry scrubbers
- > Filters – Filters remove particulate matter from the gas stream. The medium of a filter may be made of fibrous materials like cloth, granular material like sand, a rigid material like screen, or any mat like felt pad. Baghouse filtration system is the most common one and is made of cotton or synthetic fibres ( for low temperatures) or glass cloth fabrics (for higher temperature up to 290 o C).
- > Electrostatic precipitators (ESP) - The emanating dust is charged with ions and the ionized particulate matter is collected on an oppositely charged surface. The particles are removed from the collection surface by occasional shaking or by rapping the surface. ESPs are used in boilers, furnaces, and many other units of thermal power plants, cement factories, steel plants, etc
- > Inertial collectors –It works on the principle that inertia of SPM in a gas is higher than its solvent and as inertia is a function of the mass of the particulate matter this device collects heavier particles more efficiently . ‘Cyclone’ is a common inertial collector used in gas cleaning plants.
- > Scrubbers– Scrubbers are wet collectors. They remove aerosols from a stream of gas either by collecting wet particles on a surface followed by their removal, or else the particles are wetted by a scrubbing liquid. The particles get trapped as they travel from supporting gaseous medium across the interface to the liquid scrubbing medium. Gaseous pollutants can be removed by absorption in a liquid using a wet scrubber and depends on the type of the gas to be removed e.g. for removal of sulphur dioxide alkaline solution is needed as it dissolves sulphur dioxide. Gaseous pollutants may be absorbed on an activated solid surface like silica gel, alumina, carbon, etc. Silica gel can remove water vapour . Condensation allows the recovery of many by products in coal and petroleum processing industries from their liquid effluents.
Control of vehicular pollution
- - emission standards for automobiles
- - To reduce emission of sulphurdioxide, sulphur content in diesel has been reduced to 0.05%.
- - Addition of lead in petrol has been banned
- - CNG is being encouraged for use in public transport vehicles.
- - Pollution control certificate is required
- W .H.O. (W orld Health Organization) has prescribed optimum noise level as 45 dB by day and 35 dB by night. Anything above 80 dB is hazardous.
- maintenance of vehicles.
- noise attenuation walls
- appropriate insulation
- not be permitted at night
- green belt of trees is an efficient noise absorber
- mercury causes Minamata disease
- Lead causes displexia
- cadmium poisoning causes Itai – Itai disease
Sources of soil pollution
- Plastic bags
- Agricultural sources like pesticide, fertilizer, herbicide.
- Non-ionizing radiations are constituted by the electromagnetic waves at the longer wavelength of the spectrum ranging from near infra-red rays to radio waves. These waves have energies enough to excite the atoms and molecules of the medium through which they pass, causing them to vibrate faster but not strong enough to ionize them. In a microwave oven the radiation causes water molecules in the cooking medium to vibrate faster and thus raising its temperature.
- At higher doses (up to 100 rem), the cells might damage
- Radiation damage can be divided into two types: (a) somatic damage (also called radiation sickness) and (b) genetic damage.
- somatic radiation damage include reddening of the skin, loss of hair , ulceration, fibrosis of the lungs, the formation of holes in tissue, a reduction of white blood cells, and the induction of cataract in the eyes. This damage can also result in cancer and death.
- Genetic damage refers to damage to cells associated with reproduction. This damage can subsequently cause genetic damage from gene mutation resulting in abnormalities. Genetic damages are passed on to next generation.
- Contact transmission: Some diseases can be transmitted by either direct physical contact with the infected person or the causative agent can be transmitted to the host indirectly by contact with the infected articles.
- Vehicle transmission:(a) Pathogenic organisms are transmitted through water , food, etc. When the water is infected at the source, it spreads the infection to large populations. eg Pathogens causing Cholera, Typhoid and Hepatitis. (b) Many chemical pollutants such as food additives, adulterants, poisonous industrial waste, pesticides and metals get mixed with water including underground water and are consumed by humans and animals resulting in diseases.
- Vector transmission:Vector is a carrier of pathogen. Mosquito spend a part of their life cycle in water and is Vector for disases such as malaria, yellow fever , encephalitis, filaria and dengue.
- Typhoid - Salmonella typhi
- Cholera - Vibrio cholerae
- Bacterial Diaorhoe - Shigellaspp
- Leptospirosis - Leptospira
- Bilharzia - Schistosomaspp
- Filaria - Wuchereria
- Dengue - Barbo
The tumors can be either benign or malignant. benign tumors are not harmful. malignant tumors are cancerous herbicides like 2,4-dichlorophenoxyacetic acid (2,4-D) has been associated with a 200-800% increase of NHL(Non-Hodgkin’ s L ymphoma)
Blue Baby disease nitrogenous fertilizers increased levels of nitrates this causes methaemoglobinaemia particularly in bottle fed infants who are very sensitive to this pollutant Methaemoglobin is formed when iron in the haemoglobin molecule is oxidized from Fe 2 + (ferrous) to Fe 3 + (ferric) form. Due to reduced carrying capacity for oxygen the babies gradually acquire a blue tinge and hence the name – “Blue Baby disease”
Arsenic is associated with copper, iron and silver ores. Arsenic is emitted from fossil fuel burning. Liquid effluents from fertilizer plants also contain arsenic. Ground water contamination with arsenic is very common If a person drinks water contaminated with arsenic for about 10 years, dark spot develop on the upper chest, back and arms known as melanosis.The next stage is keratosis in which palms become hard and patient may suffer from diarrohea, stomach pain, breathing problems
Mining especially of zinc and metallurgical operations, electroplating industries, etc. release cadmium in the environment It may cause hypertension, liver cirrhosis, brittle bones, kidney damage and lung cancer . Itai-itai disease Problems of heavy metal toxicity can be prevented by avoiding the use of utensils made from materials containing these heavy metals or use of drinking water and consuming fish having these heavy metals.
- Black lung disease is the common name for pneumoconiosis (CWP) or anthracosis, a lung disease of older workers in the coal industry ,
- Environmental degradation also increasing vulnerability to natural disasters. Natural disasters can not be prevented but their damaging impact can be reduced
- Flood : outbreak of epidemics like diarrhea, cholera, jaundice or viral infections. may affect soil characteristics and may turn them infertile. The floodwater can be reduced by reducing the run-off water through afforestation. Construction of dams . Measurement of intensity of rainfall in the catchment area provide sufficient clue to hydrology engineers to calculate the possible submergence area along a river well before the flooding occurs. Land use planning. No major development should be permitted in flood prone areas. Deforestation in the catchments areas should be discouraged.
- Drought :low rainfall, drying of rivers, lakes, reservoirs. As per Meteorological Department if rainfall is deficient by more than 10% of the annual average rainfall, the condition is said to be that of drought. water conservation measures, economizing water consumption, reusing the wastewater for inferior uses, sowing low water-consuming crop, Rain water harvesting.
- Earthquake : outbreak of epidemics like cholera, diarrhoea, and infectious diseases. Utilities such as water supply , sewerage, communication lines, power -lines, transportation network, and railways get damaged. build by laws and safety requirements. Physical characteristics of soil should be analysed in order to ensure the strength to withstand the earthquake.
- Cyclone: generally followed by heavy rains causing floods, Warning and evacuation is done along the projected path, mudslide or landslide, in the coastal areas may cause sea waves to enter on land, cause saline water contamination of soil
No development should be permitted in cyclone – prone areas, Coastal green belt has been found very effective in minimizing the effects of cyclones Tsunami: warnings to endangered coasts immediately after an earthquake and several hours before the arrival of the tsunami. As the waves approach the continental coasts, friction with the increasingly shallow bottom reduces the velocity of the waves. This results in increased wave height up to 50 meter
Epidemics Outbreaks of communicable disease. Mad Cow Disease (Bovine spongiform encephalopathy) caused by an infectious agent that has a long incubation period, between two and five years
Desertification : The land that has lost its productivity (ability to grow plants) is called a desert. principal causes are over cultivation, overgrazing, deforestation, and salt accumulation due to irrigation
Important ozone depleting chemicals : Carbon tetrachloride, Methyl chloroform, HCFC-22, CFCs A small amount of uv-radiation is necessary for well-being of human beings and other organisms, such as uv-B promote synthesis of vitamin-D. UV-radiation also act as a germicide to control microorganisms
Sum total of all the variety of living organisms on earth constitute biodiversity. Biological diversity is usually considered at three different levels – a) genetic diversity i.e. at genetic level , b) species diversity i.e. at the level of species, and c) ecosystem diversity i.e. at the level of ecosystem.
- - Genetic diversity : Each species stores an immense amount of genetic information. it enables a population to adapt to its environment and to respond to the process of natural selection. If a species has more genetic variation, it can adapt better to the changed environmental conditions. Lower diversity in a species leads to genetic uniformity of genetically similar crop plants. This homogeneity is desirable in producing uniform quality of grain. But genetic uniformity restricts adaptability of a species to environmental stress as all the plants have same level of resistance. New genetic variation in individuals occurs by gene and chromosomal mutation, and in organisms with sexual reproduction. India has high genetic diversity and is regarded as a Vavilov’ s centre of high crop genetic diversity – so named after the Russian agro-botanist N I Vavilov , who identified eight such centres of origin of cultivated plants around the world.
- - Species diversity : refers to the variety of species within a geographical area. Species richness –refers to the number of various species in a defined area. Species abundance –refers to the relative numbers among species. Taxonomic orphylogenetic diversity –refers to the genetic relationships between different groups of species. When taxonomically unrelated species are present in an area, the area represents greater species diversity as compared to an area represented by taxonomically related species.
- - Ecosystem diversity: It refers to the presence of different types of ecosystems. ecosystem diversity encompasses the broad differences between ecosystem, and the diversity of the habitats and ecological processes occurring within each ecosystem type. India has very diverse terrestrial and aquatic ecosystems ranging from ice-capped Himalayas to deserts, from arid scrub to grassland to wetlands and tropical rainforests, from coral reefs to the deep sea.
Reasons for biodiversity loss
- - Loss of habitat
- - Pollution
- - Overuse
- - Introduction of foreign species - For example: Parthenium, Argemone and Lantana are the common weeds of foreign origin in our country
- - Environmental degradation: A vast array of factors causing environmental degradation may result in the loss of biodiversity. Some of these factors are: global warming, increased CO2 concentration in atmosphere, nuclear radiation; UV-exposure; oil spills
About 33% of the flowering plants recorded in India are endemic to our country . Indian region is also notable for endemic fauna. For example, out of recorded vertebrates, 53% freshwater fish, 60% amphibians, 36% reptiles and 10% mammalian fauna are endemic. India accounts for only 2.4 % of the land area of the world; but it contributes approximately 8% species to the global diversity
Concept of hot spots : The criteria for determining a hot spot are: i) The area should support >1500 endemic species, ii) It must have lost over 70 % of the original habitat. Among the 25 hot spots of the world, 2 are found in India namely western ghats and the eastern Himalayas
The various benefits of biological diversity can be grouped under three categories: a) ecosystem services, b) biological resources, and c) social benefits
- Protection of water resources
- regulating and stabilizing water run-off and acting as a buffer against extreme events such as floods and droughts
- Wetlands and forests act as water purifying systems, while mangroves trap silt thereby reducing impacts on marine ecosystems.
- Soil protection
- Nutrient storage and cycling
- Pollution reduction
- Climate stability
- Maintenance of ecological processes
Biological resources of economic importance
- Food, fibre, medicines, fuel wood and ornamental plants
- Breeding material for crop improvement - rice grown in Asia is protected from four main diseases by genes contributed by a single wild rice variety
- Future resources - Many presently under-utilised food crops have the potential to become important crops in the future. Knowledge of the uses of wild plants by the local people is often a source for ideas on developing new plant products.
- Ecotourism, photography , painting, film making and literary activities
- Cultural values - Human cultures have co-evolved with their environment and biological diversity can be impart a distinct cultural identity to different communities. Tulsi (Ocimum sanctum), Peepal (Ficus religiosa), Khejri (Pr osopis cineraria)
More than 45000 species of plants and 81,000 species of animals are found in India.
The trans-Himalayan region with its sparse vegetation has the richest wild sheep and goat community in the world. The snow leopard (Panthera uncia) and Black-necked Crane (Grus nigricollis)are found here. The Great Indian Bustard (Ardeotis nigriceps) which is highly endangered bird, is found in (Gujrat) region, rich in extensive grasslands
Major reef formations in Indian seas occur in the Gulf of Mannar, Palk Bay , Gulf of Kutch, the Andaman and Nicobar Islands and the Lakshadweep.
CAUSES OF BIODIVERSITY DEPLETION
- Direct ways:Deforestation, hunting, poaching, commercial exploitation.
- Indirect ways: Loss or modification of the natural habitats, introduction of exotic species, pollution, etc.
- Natural causes - Climate change.
Among these causes, habitat destruction and over-exploitation are the main
Lantana camara (an American weed) has invaded many forest lands in various parts of India and wiped out the native grass species
The World Conservation Union (IUCN)(formerly known as International Union for the Conservation of Nature and Natural Resources, IUCN) has recognized eight Red List categories
- 1. Extinct
- 2. Extinct in the wild
- 3. Critically endangered
- 4. Endangered
- 5. Vulnerable
- 6. Lower risk
- 7. Data deficient
- 8. Not evaluated
According to the Red List, in India,44 plant species are critically endangered., 113 endangered and 87 vulnerable. Amongst animals, 18 are critically endangered, 54 endangered and 143 Vulnerable.
Plant : Berberis nilghiriensis , Bentinckta nicobarica, Cupressus cashmeriana
Animals: Sus salvanius, (Pigmy hog) , Allurus fulgens, (Red Panda) , Antilope cervicapra, (Black buck)
Kaziranga sanctuary (Assam) – One-horned rhinoceros
Manas sanctuary (Assam) – Wild buffaloes
Gir forest (Gujarat) – Lions, chital, sambar, wild bears
Kelameru bird sanctuary (Andhra Pradesh) – Pelicans and marine birds
Dachigam sanctuary (Jammu and Kashmir) – Kashmir stags, Himalayan tahr, wild goats, sheep, antelopes.
Bandipur sanctuary (Karnataka) – Indian bison, elephants, langurs
Periyar sanctuary (Kerala) – Elephants, barking deer , sambhar
Kanha National Park (Madhya Pradesh) – Tiger , leopards, wild dogs
Simipal National Park (Orissa) – Mangroves, marine turtles lay eggs
Bharatpur bird sanctuary (Rajasthan) – Ducks, herons
Corbett National Park (Uttaranchal) –Tigers, barking deer , sambar , wild bear , rhesus monkey .
Tigers which were once abundant in Indian forests have been hunted. As a result tiger population within the country declined drastically from estimate of 40,000 at the turn of century to 1200 by the 1970. This led to initiate the Project Tiger in 1973 with the objective of conserving and rescuing this species from extinction. In 2007, there were more than 40 Project Tiger wildlife reserves covering an area of 37,761 km². Project Tiger helped to increase the population of these tigers from 1,200 in the 1970s to 3,500 in 1990s. However , a 2008 census held by Government of India revealed that the tiger population had dropped to 1,41 1. A total ban has been imposed on hunting of tigers and trading in tiger products at the national and international levels. Elaborate management plans are made for each of the tiger reserves for tiger habitat improvement and anti -poaching measures.
Launched in February , 1992 to assist states having free ranging populations of wild elephants to ensure long-term survival of identified viable populations of elephants in their natural habitats. The project is being implemented in 22 states.
Objective: 1. To protect elephant , their habitat & corridors 2. To address issue of Man-animal conflict 3. welfare of domesticated elephants
Crocodile breeding and management project
This project was started in 1976 with FAO - UNDP assistance to save three endangered crocodilian species, namely , the fresh water crocodile, salt water crocodile and the rare gharial. The project surveyed the crocodile habitats and facilitated their protection through declaration of sanctuaries and National Parks. Captive breeding and reintroduction or restocking programmes involved careful collection of eggs from the wild. Thousands of crocodiles of three species have been reared at sixteen centres and several of these have been released in the wild. Eleven sanctuaries have been declared specially for crocodile protection including the National Chambal Sanctuary in Madhya Pradesh. Others are Satkoshia (Orrisa),
- - Botanical gardens, zoos
- - Gene Banks
- - Cryopreservation
- - storage of material at ultra low temperature of liquid nitrogen (-196 0 C)
- - Conservation at molecular level (DNA level)
Biological Diversity Act, 2002
- This Act provides for setting up of a National Biodiversity Authority (NBA), State Biodiversity Boards (SBB) and Biodiversity Management Committees (BMC) in local bodies.
- All foreign nationals organizations require prior approval of NBA for obtaining biological resources and/or associated knowledge for any use.
- Similarly , Indian nationals or organizations will require to give prior intimation to the concerned SBB about any biological resources being imported for commercial use. The SBB may prohibit the import if found to violate the objectives of conservation, sustainable use and benefit sharing.
- However, local people and communities of the area, including Vaids and Hakims will have free access to use biological resources within the country for their own use, medicinal purposes and research.
- While granting approvals, NBA will impose terms and conditions to secure equitable sharing of benefits.
- There is a enabling provision for setting up a framework for protecting traditional knowledge.
- The monetary benefits, fees and royalties, as a result of approvals by NBA are to be deposited in National Biodiversity Fund which will be used for conservation and development of areas from where the resource has been accessed, in consultation with local self government.
- World Wide Fund for Nature (WWF) and World Conservation Union supports projects to promote conservation and appropriate development of Biosphere Reserves.
Soil erosion is the loosening and displacement of topsoil particles from the land. Soil erosion is a natural process that occurs on all lands. Land degradation is the deterioration in the quality of land. Degradation of land results in loss of crop production capacity of the land. Soil erosion in nature may be (a) a slow process (or geological erosion) or (b) a fast process (Man induced changes or natural calamities) promoted by deforestation, floods, tornadoes or other human activities. These two processes are explained below:
- (a) Geological erosion is a slow process that continues relatively unnoticed and has been occurring for millions of years. The first phase of this soil forming process is called weathering which is a physico- chemical process that leads to the break down of rocks by wind and water into small fragments and formation of soil particles.
- (b) Accelerated (Speeded up) soil erosion occurs when the protective vegetation cover is destroyed. This may occur due to natural causes like flooding or due to human activities. One of the main human activitiy responsible for accelerated soil erosion is cultivation of land. Land under cultivation is more vulnerable to natural agencies like wind and water.
- - Raindrop erosion
- - Sheet erosion
- - Rill erosion
- - Stream bank erosion
- - Landslide:
- - Coastal erosion
- - (i) Siltation: blown by wind in a series of short bounces.
- - (ii) Suspension: transported over long distances in the form of suspended particles.
- - (iii) Surface creep: transported at ground level by high velocity winds.
Agricultural practices can lead to accelerated soil erosion 1. Tilling or ploughing increases the chances of erosion because it disturbs the natural soil surface and protective vegetation. 2. Continuous cropping: 3. Cultivation on mountain slopes: without appropriate land treatment measures such as bounding, terracing and trenching cause soil erosion and loss of soil nutrients. 4. Monoculture practices can lead to soil erosion (i) A monoculture crop is harvested all at one time, which leaves the entire fields bare exposing it to both water and wind. (ii) In the event any disease or pest invades the field , the entire crop is usually wiped out leaving the bare soil susceptible to water and wind.
Land Degradation Classified on the basis of productive capacity of the land. Slight degradation - crop yield potential is reduced by 10%. Moderate degradation - 10-50% reduction in yield potential and severely degradation - yield potential is lost more than 50%. Some causes of land degradation are:
- use of agrochemical (chemical fertilizers and pesticides)
- excessive irrigation
- cultivation of high yielding plant varieties.
Solution for preventing land degradation
- Mixed cropping
- The time or season at which a field is tilled
- Addition of organic matter
- Biological pest control: The cottony cushion scale pest (Icerya pur cahsi) is controlled biologically on a large scale by its predator, the lady bird beetle. At present some 15,000 naturally occurring micro-organisms or microbial byproducts have been identified as potentially useful biological pesticides.
Promotion of CFLs (Compact Fluorscent Light Bulbs)
- Mercury is an essential element in the opera tion of fluorescent lighting. It allows the bulbs to be an efficient light source.
- CFLs use less electricity than traditional light bulbs (75%) less), they reduce demand for electricity.
- CFLs contain very small amount of mercury-an average of 4 milligrams in each bulb.
Bureau of Energy Efficiency (BEE) is an agency of the Government of India, under the Ministry of Power created in March, 2002 under the provision of Energy Conservation Act. The agency function is to develop programs which will increase the conservation and efficient uses of energy in India.
- The government has made it mandatory or compulsory for appliances in India to have ratings by the BEE. 1 star -low, 5 star- high rating
- The BEE Star Energy Efficiency Labels have been created to standardize the energy efficiency ratings of different electrical appliances and indicate energy consumption under standard test conditions.
- The Indian Renewable Energy Development Agency (IREDA) provides financial helps for the purchase of PV (Photovoltaic) systems.
- Fuel cells: Highly efficient power-generating systems that produce electricity by combining fuel (hydrogen) and oxygen in an electrochemical reaction or fuel cells are electrochemical devices that convert the chemical energy of a fuel directly and very efficiently into electricity (DC) and heat, thus doing away with combustion. Fuel cells are efficient and clean energy producer. Fuel cells have been used in space flights and being introduced in electric vehicles for reducing urban air pollution. Fuel-cell-powered EV's (electric vehicles) score over battery operated EV's in terms of increased efficiency and easier and faster refueling.
Biodiesel does not contain any petroleum but it substitutes for petroleum in the same conventional engines, name of plants for biodiesel are (1) Ratanjot or Jatropha curcas (2) Nagchampa or Callophyllum ionophyllum (3) Rubber seeds or Hevea braziliensis.
Carrying capacity is maximum load or pressure or use that the environment can withstand by economic or other human activities.
Humanity's ecological footprint exceeds the earth's ecological capacity to replenish its renewable resources and absorbs the waste. Humanity is consuming the renewable resources faster than the earth can renew them. The ecological footprint is a measure of human demand on the Earth's ecosystems. It represents the amount of biologically productive land and sea area necessary to supply the resources a human population consumes, and to assimilate associated waste.
The Ministry of Environment and Forests (MoEF)
- conservation and survey of the flora and fauna of India, forests and other wilderness areas;
- prevention and control of pollution;
- afforestation and reducing land degradation.
- responsible for the administration of the national parks of India.
- nodal agency in the country for the United Nations Environment Programme (UNEP).
Central Pollution Control Board CPCB, is statutory organisation, was constituted in September, 1974 under the Water (Prevention and Control of Pollution) Act, 1974. Further, with the powers and functions under the Air Act, 1981. It serves as a field formation and also provides technical services to the provisions of the Environment (Protection) Act, 1986. In India, states do not pursue independent environmental policy of their own but adopt the policies formulated at the national level subject to such variations as may be necessary to suit to the local conditions.
IBWL The IBWL (Indian Board of Wild Life) is the apex advisory body in the field of Wildlife Conservation in the country and is headed by the Honorable Prime Minister of India. Provides advise to central and state governments on matters reg conservation and control of poaching of wild life. Advises on setting up National parks, sanctuaries,etc..,
Some important revolutionary varieties of wheat are ‘Kalyan Sona’, ‘Sonalika’ and ‘Sharbati Sonora two semi dwarf varieties namely Lerma Rajo and Sonora-64 were chosen and were released for cultivation in irrigated fields. Sharbati Sonara - is mutant variety produced by mutation breeding by subjecting Sonara 64 to gamma and ultraviolet radiations. ‘Sharbati Sonara’ had bold, amber , and lustrous grains and was found to contain 15-25% more protein than the parent Sonara 64.
Cattle population in India constitutes 25% of the world cattle population but the total milk production is about 5% of the world’ s total milk production. In our country a cow on an average gives about 1.5 litre of milk per day and a buffalo 2.5 litres per day whereas a cow in some developed countries produces 8-1 1 litres of milk per day. Low milk yield in our country is due to:
- poor quality feed
- shortage of feed and fodder
- low milk yielding indigenous breeds
- Oxytocin causes milk ejection from mammary glands in nursing mothers. This hormone also causes uterine contraction, so injection of this hormone for milk release can cause pain and discomfort to the animal.
Sustainable agriculture is one that
- supports profitable production;
- protects environmental quality;
- uses natural resources efficiently;
- provides consumers with affordable, high-quality products;
- decreases dependency on non-renewable resources;
- enhances the quality of life for farmers and rural communities;
- and will last for generations to come.
Several methods adopted in sustainable agriculture are:
- cultivation practices to increase biological and economic stability .
- selection of improved varieties to suit the need.
- soil management by proper method of tillage.
- practice of mixed cropping or diverse cropping and crop rotation.
- One of the energy efficient and pollution free method is to exploit the ability of certain microorganisms like bacteria, algae and fungi to fix atmospheric nitrogen, solubilize phosphorus, decompose organic material or oxidize sulphur in the soil. When they are applied in the soil, they enhance growth and yield of crops, improve soil fertility and reduces pollution.
Integrated pest management (IPM) program: In this approach, each crop and its pests are evaluated as parts of an ecological system. Then farmers develop a control programe that includes cultivation, biological and chemical methods applied in proper sequence and with the proper timing. The aim of IPM is not to eradicate the pest population completely but to keep the crop damage to economically tolerable level. Farmers monitor the field and when they find the pest level to be high enough, they first use biological methods and cultivation practices to control and then use small amounts of insecticides mostly insecticides derived from plants as a last resort.
- Pest on cucumber plant called red spider mite is controlled by using a predatory mite
- Citrus fruits in California heavily damaged by scale insects which were controlled by Australian ladybird which ate away the insects.
- Mealy bug pest of Cassava plant were controlled by a parasitoid wasp which was its natural enemy .
- Hormones are used that disrupt the insects normal life cycle, thereby preventing it from reaching maturity and reproducing and multiplying.
- Pest and disease resistant crop plants can be produced by genetic engineering. Example is B t cotton,
With conventional breeding practices reached their saturation point, the “gene revolution” seems to hold lot of potential. (i) herbicide tolerant, (ii) insect resistant, (iii) resistant to pathogens like virus, bacteria and fungi
Golden Rice a transgenic with enhanced vitamin A content producing nutritionally rich rice to save many lives. Salt and flood tolerance genes have been incorporated in rice so that B t rice in China shows higher yield and a huge reduction in pesticide use. Such rice can be grown on saline soil.
CONCEPT OF ECOLABELLING
Labeling of environmentally beneficial goods and resources extracted by more sustainable methods can help consumers decide which goods and services to buy. Product ecolabelling can encourage companies to develop green products and services and help consumers select more environmentally beneficial products and services. Eco-labels are also being used to certify that the fish bearing ecolabels were caught by using sustainable fishing methods and also for timber products to certify and trees were harvested in accordance with by sustainable forest management principles.
Objectives of ecolabelling
- Protecting the environment and to make consumers aware of environment issues.
- Encouraging efficient management of renewable resources to ensure their availability to future generations.
- Promoting efficient management of non-renewable resources, including fossil fuels.
- Encouraging protection of ecosystems and species diversity .
- Encouraging proper management of chemicals to prevent pollution .
Ecolabelling in India
Ecolabelling scheme of Government of India supports cleaner (environmentally friendly) production practices. Presently the scheme is limited to household and some consumer products to meet certain environment criteria alongwith quality requirements of Indian standards. The label is known as ‘Eco mark’. The products for which notifications have been issued for the criteria are: toilet soaps, detergents, paper, architectural points and laundry soaps. Eco-label is issued by the Central Pollution Control Board (CPCB) is represented by a pitcher or an ‘earthen pot’indicating that the product is not harmful to the environment like as an earthen pot which is made of soil and after its use returned to it the soil. It is without causing any harmful effect on the environment.
After the United Nations Conference on Human Environment, held in Stockholm in 1972. Indian constitution was amended to include protection of the environment as a constitutional mandate and created Wild life protection Act, 1972.
Article 48A : The State shall endeavour to protect and improve the environment and to safeguard the forests and wildlife of the country.
Article 51A : It shall to be duty of every citizen of India to protect and improve the natural environment including forests, lakes, rivers and wild life and h ave compassion for living creatures.
The Environment (Protection) Act of 1986 (EPA) came into force soon after the Bhopal Gas Tragedy and is considered umbrella legislation as it fills many lacunae in the existing legislations.
The Water (Prevention and Control of Pollution) Act of 1974 and Amendment, 1988
- Vests regulatory authority in State Pollution Control Boards and empowers to establish and enforce effluent standards for factories discharging pollutants into water bodies. A Central Pollution Control Board performs the same functions for Union Territories and formulate policies and coordinates activities of different State Boards.
- The State Pollution Control Boards control sewage and industrial effluent discharges by approving, rejecting or impose conditions while granting consent to discharge.
- The Act grants power to the Board to ensure compliance with the Act by including the power of entry for examination, testing of equipment and other purposes and power to take the sample for the purpose of analysis of water from any stream or well or sample of any sewage or trade effluents.
- Board may close a defaulting industrial plant or withdraw its supply of power or water by an administrative order; the penalties are more stringent, and a citizen's suit provision supports the enforcement machinery.
The Water (Prevention and Control of Pollution) Cess Act of 1977
- to generate financial resources to meet expenses of the Central and State Pollution Boards.
- creates economic incentives for pollution control and requires local authorities and certain designated industries to pay a cess (tax) for water effluent discharge.
- The Central Government, after deducting the expenses of collection, pays the central board and the states such sums, as it seems necessary.
- To encourage capital investment in pollution control, the Act gives a polluter a 70% rebate of the applicable cess upon installing effluent treatment equipment.
The Air (Prevention and Control of Pollution) Act of 1981 and amendment, 1987
- To implement the decisions taken at the United Nations Conference on the Human Environment held at Stockholm in June 1972, Parliament enacted the nationwide Air Act.
- The Air Act's framework is similar to that of the Water Act of 1974.
- To enable an integrated approach to environmental problems, the Air Act expanded the authority of the central and state boards established under the Water Act, to include air pollution control.
- Under the Air Act, all industries operating within designated air pollution control areas must obtain a consent from pollution board
- The states are required to prescribe emission standards for industry and automobiles after consulting the central board and noting its ambient air quality standards.
- Same powers as Water Act
- Now, the boards may close down a defaulting industrial plant or may stop its supply of electricity or water. A board may also apply to the court to restrain emissions that exceed prescribed limits. Notably, the 1987 amendment introduced a citizen’s suit provision into the Air Act and extended the Act to include noise pollution.
The Wild Life (Protection) Act of 1972 and Amendment, 1982
Provides for state wildlife advisory boards, regulations for hunting wild animals and birds, establishment of sanctuaries and national parks, regulations for trade in wild animals, animal products and trophies, and judicially imposed penalties for violating the Act. Harming endangered species listed in Schedule 1 of the Act is prohibited throughout India. Hunting species, like those requiring special protection ( Schedule II), big game (Schedule III), and small game (Schedule IV), is regulated through licensing. A few species classified as vermin (Schedule V), may be hunted without restrictions. Wildlife wardens and their staff administer the act.
An amendment to the Act in 1982, introduced a provision permitting the capture and transportation of wild animals for the scientific management of animal population.
India is a signatory to the Convention of International Trade in Endangered Species of Fauna and Flora (CITES, 1976). Under this convention, export or import of endangered species and their products are governed by the conditions and stipulations laid down therein. Indian government has also started some conservation projects for individual endangered species like Hungal (1970), Lion (1972), Tiger (1973), Crocodiles (1974), Brown-antlered Deer (1981) and Elephant (1991-92).
Declaring National parks, sanctuaries and closed reserves are also dealt.National park and WL Sanctuary deals with only particular wild animal species.
- - State Govt by notification may declare any area with in or out of sanctuary as NP, and to change boundaries of such area is done only by another resolution of state legislature.
- - No person shall, destroy, exploit, or remove any wildlife from a National Park or destroy or damage the habitat or any wild animal or deprive any wild animal or its habitat within such National Park except under and in accordance with a permit granted by the Chief Wildlife Warden and no such permit shall be granted unless the State Government, being satisfied that such destruction, exploitation, or removal of wildlife from the National Park is necessary for the improvement and better management of wildlife.
- - No animal should be allowed for grazing.
Wild life Sanctuary
This also notified by state government.
- 1. Boundaries not fixed by legislation.
- 2. All rights of people within a National Park have to be settled while rights over land can be allowed inside a Sanctuary.
- 3. Grazing of livestock can be permitted inside a Sanctuary but not inside a National Park.
- 4. A Sanctuary can be upgraded as a National Park. However a National Park cannot be downgraded as a Sanctuary.
Biosphere Reserve 1) Multi-purpose protected areas 2) all plants and animals are preserved in its natural habitat. that is, both the flora and fauna are protected 3) it promotes research in ecological conservation and environment preservation 4) its aim is also to provide facility for education & awareness.
The Forest (Conservation) Act of 1980 (1927)
- The 1927 Act deals with the four categories of the forests, namely reserved forests, village forests, protected forests and private forests.
- A state may declare forest lands or waste lands as reserved forest and may sell the produce from these forests.
- Any unauthorized felling of trees quarrying, grazing and hunting in reserved forests is punishable with a fine or imprisonment, or both reserved * * forests assigned to a village community are called village forests.
- The state governments are empowered to designate protected forests and may prohibit the felling of trees, quarrying and the removal of forest produce from these forests.
- The preservation of protected forests is enforces through rules, licenses and criminal prosecutions. Forest officers and their staff administer the Forest Act.
- Prior approval of the Central Government is required for diversion of forest lands for non -forest purposes.
- An Advisory Committee constituted under the Act advises the Centre on these approvals.