FEW RELEVANT QUESTIONS
Before we start the topical elaboration some pertinent questions are asked at the forefront to our readers.
These are the most valid questions, the answers to which must be known to a “well-read” person as per the demands of UPSC.
Asking them in the beginning itself will in a way “orient” the minds of our readers so that they read the content in a way which provides them with optimum tools to have the most comprehensive answers of the same after they finish this subject.
Before you read topics as mentioned in the content which we have dealt in-detail, the below portion is vital and should be dealt holistically for the exam. We have put efforts to present you this subject in well gelled-up and present like an interesting story.
We have provided previous year question papers and some analysis of the same. It is highly recommended that you go through the same and you will realise that every question requires an analysis. The questions will test how well you understood the things you have studied and how well you can analyse them. Therefore, Analytical abilities are more important. Just like exercise can make your body fit and healthy, analysis can make your mind healthy and useful.
Concentrate on Analytical ability, improve your thoughts by reading and continuously revising the subject, practice and improve the originality of your mind. Practice is must. Mock tests and solving previous question papers helps you.
When you done with all these, automatically you will be able to select correct answer in Prelims and write quality answer within time and word limit in Mains.
Some important tips how you can improve your ‘Analytical Skills’ and have ‘Sound Opinion’ on this subject
“INDISPENSABLES” – YOU CANNOT IGNORE
• What is Environment?
• Environment and Ecology – Are they interconnected?
• World and Environment
• Global Warming – Is it a science or an ecological activism?
• India and its environmental concerns
• What is India doing to maintain Environmental sustainability?
• Environmental laws in India and how the same evolved over years after 1972
• Recent Environmental laws – Is Government becoming too proactive in constructing newer laws in this domain or do you think more needs to be done?
• Environmental laws in the light of recent HEP activism in India
• Ecological and Environmental laws can only become sustainable when it is participative
• Land Resettlement and Rehabilitation laws – an utter disregard for participative model
• Recent debate on Tiger Reserve buffer vs Core areas – Enlarge this debate to sustainable and ecologically sensitive tourism
• Recent International summits on ecological concern
• Renewable Economy Model
• Environment Sustainability and Sustainable Growth Model – Are they mutually complementary – Discuss under the Rio+20 conference agreement
• How can ecological sustainability and economical growth both be maintained? How can India do this?
YOU MUST ALSO KNOW
• A growing concern
• Shaping International relations
• India vis-à-vis environmental diplomacy
• Carbon trading and its evolution
• Carbon trading and its pros and conservation
• 2015 United Nations Climate Change Conference, COP 21 – held in Paris
• Environmental jurisprudence
• Rio Summit again highlighting the ecological concerns
• India at the International stage regarding environment
• Domestic executive, legislative and judiciary actions and proactive measures to sustain environmental equity
• Ground root work done to ameliorate ecological harm
• Organic farming Vs Chemical agriculture
• Post Consumerism stage is needed to maintain ecological sustainability
ECO – SYSTEMS AND BIO – DEVERSITY PAPER -4
Ecology (Greek: Oikos – home, logos – study): is a branch of biology that deals with the inter-relationship amongst organisms and interactions between organisms and their environment.
The term ecology was coined by Ernst Haeckel (1869) though its first authentic use was made by Reiter (1885).
TWO BRANCHES OF ECOLOGY
The study of reciprocal relationship between every stages of development of a population or species and its environment. This ecology is also called as autoecology.
The study of reciprocal relationship between composition, organisation and development of communities and their environment.
It is a distinct living entity which carries out all life processes in its body, separate from those in other individuals. An individual organism is the basic unit of ecological hierarchy and it continuously exchanges materials and information with its environment. Hereditary characters are transferred during this process.
It is a group of similar individuals in a particular geographical area or space. The different populations of same organisms present in particular geographical areas are called as local population or demes. A local population adapted genetically to its particular environment is called Ecotype.
Biological or Biotic Community:
It is an assemblage of populations of different species of plants, animals, bacteria and fungi which live in a particular area and interact with one another through competition, predation and mutualism etc.`
It is the segment of nature consisting of a biological community and its physical environment both interacting and exchanging materials as well as energy.
A large regional unit delimited by a specific climatic zone, having a particular major vegetation zone and its associated fauna.
Ex: Tundra, Desert, Tropical Rain Forest, Ocean etc.
It is biologically inhabited part of earth along with its physical environment consisting of lower atmosphere, land and water bodies.
INTERACTIONS IN BIOTIC community
One is benefited without the other being harmed. It is of two types, periodic contact and continuous contact.
* Clone fish is able to protect itself by living in the company of sea anemones.
* Pilot Fish and sucker Fish remains attached with shark for their survival.
MUTUALISM OR SYMBIOSIS:
It is a mutually beneficial relationship or interaction between individuals of two different species.
Ex: Rhizobium (nitrogen fixation) and roots (Shetter, food) in nodulated legumes.
It is a non-obligatory beneficial relationship that develops when two different organisms get associated with each other.
Crocodile Bird rids crocodile of leches sticking inside its mouth.
Shrimp eats up the parasites on the body of Fish.
Without deriving much benefit, one inhibits the other by secreting allochemics. The phenomenon is called as antibiosis.
Smoother crops donot allow weeds to grow
Ex: Sunflower, Barely etc.
It is rivalry for obtaining the same source. Competition is of two types, viz,
Intra specific Competition.
Inter Specific Competition
Intra specific Competition:
It is a competition amongst members of same species for common resource. Intra specific competition for food, space and mate.
Cannibalism (Eating members of the same species) reduces this competition
Ex: Snakes, Scorpions etc.
Inter specific Competition:
It is rivalry amongst members of different species. Every type of organism has a particular niche. Where niche is the unique functional role or place of a species in an ecosystem. No two types of organisms can have the same niche. One of the two is eliminated. The phenomenon is called as Gause Hypothesis or Principles of Competitive Exclusion.
Parasitism an interaction between two organisms in which one we called as parasite derives synthesized food from another living organisms called host. Besides food, parasites also obtain shelter from their host.
It is a mechanism of biology control that helps in keeping the population of various organisms under check.
Carnivorous plants are also predators
Ex: Drosera, Nepenthes etc.
The concept of ecosystem was first put forth by A.G. Transley (1935). He defined it as “the system resulting from the integration of all living and non-living factors of the environment”.
According to Odum (1965), “the ecosystem is the basic functional unit of organisms and their environment interacting with each other”.
STRUCTURAL COMPONENTS OF ECOSYSTEM.
Abiotic (Non – living) Components.
Biotic (living) Components.
ABIOTIC (NON – LIVING) COMPONENTS:
All non – living factors of an ecosystem. They are as follows:
These include elements like C, H, O, N, P, S etc. They are absorbed by the plants through root hairs.
These are proteins, carbohydrates and lipids etc.
They include physical factors like light, temperature, atmospheric pressure and rainfall etc. Abiotic components supports the biotic components and no ecosystem can occur without abiotic components.
BIOTIC (LIVING) COMPONENTS:
All living organisms of an ecosystem constitute the biotic component. The amount of living matter present in an ecosystem is called standing crop. If standing crop expressed as weight it is called as Bio-Mass. The biotic components is further classified depending on their nutritional (tropic) relationship as follows.
These are green plants (Autotrophic) having chlorophyll. They manufacture energy rich food materials by photosynthesis.
Consumers: All living organism which have no chlorophyll must obtain their energy from green plants directly or in directly. Consumers can be macro or micro. They occur in a food chain in the order of primary consumers, secondary consumers and tertiary consumers. Micro consumers are also called decomposers or saprotrophs or osmotrophs. They include chiefly batteria and fungi etc.
Decomposers: These decompose dead organic substances of producers and consumers into a simple substances Ex: Bacteria, fungi etc.
TYPES OF ECOSYSTEM
All the ecosystems of the world can be divided into two major groups based on human utility. They are as follows.
Schematic Representation of types of ecosystem:
These operate by themselves under natural conditions without human interference. Natural ecosystem again classified in to two categories Viz,
Forests, Grass land, Deserts and Tundra are the four main terrestrial ecosystems. They are discussed in details below.
Forests are divided into Rain water Forest Ecosystem. Ex: Amazon Bain, Congo Basin in Africa and western Ghats in Karnataka etc.
Deciduous Forest Ecosystem:
Ex: South Asia, S-E Asian countries especially Chhotanagpur plateau in India, combodia and Myannmar etc.
Temperate Forest Ecosystem (countries of Mediterranean regions like France, portuagal, Italy etc).
Coniferous Forest Ecosystem
Ex: Siberian Region, Himalayas etc.
Grass Land Ecosystem:
Grass Lands can be classified as Tropical Grassland Ecosystem (Ex: Brazilian High Land) and Temperate Grass Land Ecosystem (EX: Russian Steppes, Poland South American Pampas, North American prairies and Australia Downs etc).
Deserts can be classified as Tropical Desert Ecosystem.
(EX: Thar, sahara, Arabian, Atacama Desert of chile and western Austrian Desert).
Temperate Desert Ecosystem.
(Ex: Gobi deserts, Patagonia deserts in south America etc).
Tundra type of ecosystem is found in polar and sub polar regions.
(Ex: Alaska region, North Canada, Green Land, Margions of Antarctica etc).
Limnic, Marine and littoral ecosystems are main types of Aquatic ecosystem.
It is the ecosystem observed in fresh water. It is also called as “Fresh water Ecosystem”. It can be again categorised into lentic and Lothic. Lentic deals with ecosystem its based on the standing of water bodies like pond and lake etc. and lothic deals with ecosystem based on the flowing or running of water bodies like rivers, streams, and water falls.
Coastal based ecosystem is called as Littoral. It is the junction between continents and oceans.
Ex: Mangroves, Estuaries, Deltas and Zagoons etc.
This ecosystem is based on waters of seas and oceans is called as marine ecosystem. It can be categorized into Nerdic, pelagic, Benthic and Abyssal.
Marine Ecosystem Division
Artificial/ Man-Made Ecosystem:
These are products of modern human civilization. Crop lands, Industries, Laboratories, clinics, Agna Forms, space stations etc all other different types of man made ecosystem.
The Eutrophication (Greek: Eutrophia mean adequate and healthy nutrition) is defined as the addition of artificial (or) natural substances such as nitrates and phosphates through fertilizers, sewage water from industries or from municipalities etc that fertilizes the agnatic ecosystem in standing water like water in ponds, lakes and reservoirs etc. Where Lothic deals with ecosystem in flowing or running water of streams, rivers, springs and canals etc.
EUTROPHICATION FLOW CHART
Effects of Eutrophication
Change in ecosystem
New Species invasion
Coral is actually is living organism or animal. Coral has a symbiotic relationship (Each gives Something to the other and gets something back in return) with microscopic algae which live on coral.
Features of Coral Reefs:
They occurs in shallow tropical areas where the sea water is clean, clear and warm.
The coral reef cover in Indian waters is roughly estimated upto 19,000 sq.km.
Coral reefs are one of the most productive and complex costal ecosystems with high biological diversity.
Coral are generally slow growing colonics of animals when compare to microscopic algaes.
CLASSIFICATION OF CORAL REEFS:
Advantages of coral reefs.
Coral reefs are natural protectives barriers against erotion and strom surge.
Largest biogenic calcium carbonate producer.
They provide substrate for mangroves.
Coral reefs provide habitat for a large variety of animals and plants.
Bleaching or the paling of coral colours occurs when the densities of microscopic algae (zooxanthellae) decline and the concentration of photosynthetic pigments with in the zooxanthellae fall. This process is called as coral Bleaching.
FUNCTION OF ECOSYSTEM:
Productivity: Synthesis of organic compounds from inorganic compounds.
Energy Flow: Producers and consumers plays very important role in flow of energy in various trophical levels. Organisms that produce food are called as producers and those that cannot produce food are called as consumers.
Consumers feed on producers and in turn build up their tissues.
Consumers are primary or secondary. Where primary refers to Herbivors who feed directly on autotrophic producers.
Secondary refers to carnivorous which feed on Herbevores.
Tertiary consumers are those which feed on secondary consumers.
These are important parts of biotic component. They can be saprophytes/parasites or scavengers/detrivores. They involve in secretion of digestive enzymes. They absorb parts of organic matter, utilizing it for their own nourishment and remaining they pass on to food chain and biotic components. Thus they help in recycling of dead tissues of organic matter. Through this, they also clean up the surroundings from decomposed and dead organic matter. Hence they are called as scavengers also. They are very important for sustenance of an ecosystem.
BIOSPHERE AS AN ECOSYSTEM:
Edward suess in 1875 was the first to use the term Biosphere for the earth along with the living organisms and environment (temperature, humidity, air and water etc). According to odum (1959) “the total physical environment (Land, water, Air) of any living organism is termed as Biosphere”.
Biosphere is an open ecosystem on which astrophysical, geochemical, geological and meteorogical forces act upon. Different components of the Biosphere interact in an orderly manner with the living organisms. The interaction of components of biosphere with living organisms assures that the survival and gradual evolution of the organisms.
HIERARCHY OF ECOSYSTEMS:
MEGA ECOSYSTEM (Terrestrial, marine, littoral)
MACRO ECOSYSTEM (FORESTS)
MESO ECOSYSTEM (Rain – Forest ecosystem)
MICRO ECOSYSTEM (Pond ecosystem)
SEGMENTS OF BIOSPHERE
SEGMENTS OF BIOSPHERE WITH THEIR ECOSYSTEMS.
ECOSYSTEM OF LITHOSPHERE:
It comprises of rocks, mountains, land and other solid layers of earth. It is the one which supports the oceans and continents.
Their is a semi viscous fluid in the upper mantle of earth surface called as Asthenosphere
Rigid layer rocks of earth crust floats on Asthenospheric fluid in form of lithospheric plates. These plates are in motion and they are dynamic. These continuous movements are termed as Tectonic forces.
Volcanism, mountain building activity (orogeny seismic activity etc are caused because of the movements of lithospheric plates.
INTERNAL LAYER OF EARTH
Surface layer of lithosphere is covered with thin layer of nutrients called as “soil”. Soil formation is called as “pedogenesis”. For formation 1cm of soil takes 5000-10,000 years. Soil is formed by a combination of physical, chemical and biological processes.
Soils are rich with a variety of macro, and micro nutrient. This is crucial for plant life. This soil provides base for cultivation of crops and food production. The food security of human beings is depends on Lithosphere Via Soil.
ECOSYSTEM OF HYDROSPHERE:
It made up of water in the form of oceans. Oceans can be considered as basins between continents that store huge water bodies.
They occupy 71% of the earth surface. Pacific ocean, Atlantic ocean, Indian Oceans are the major oceans.
Pacific ocean is the largest and occupies 1/3rd of the earth surface.
Life began on earth in oceans as unicellular organisms. Bio-diversity in oceans is much greater than on land.
Hydrosphere is the source of water for sustenance of biosphere. It plays important role with hydrlog water cycle. There is a close link between Atmosphere and Hydrosphere. Water moves from Hydrosphere to Atmosphere by evaporation. Water is return to Hydrosphere by process of condensation. This continuous flow of water from hydrosphere to atmosphere and atmosphere to hydrosphere is crucial for sustenance of Biosphere. Hence it can be said that Hydrosphere has control on the global climate. A small changes in the temperature of oceanic water results in cascading effect on the global climate. The phenomenon of EL NINO/LA NINO represents the oceanic currents control on temperature. ELNINO is the abnormal rise in sea surface temperature in the pacific ocean its results in change of oceanic current.
LANINO is due to decrease in surface temperature of ocean. EL NINO and LA NINO are good example to show control of hydrosphere over global climate
ADVANTAGES OF HYDROSPHERE:
Huge reservoir of various resources for human beings. Marine food, wide variety of organisms mineral resources (like chromium, magnesium hydro carbons, fossil fuels are extracted from continental shelf and abyssal plain.
Hydrosphere is also source of energy.
Ocena thermal energy
Hydrosphere also helps in Navigation, shipping is crucial for global economic trade and transportation as well as in bonding cultural contacts.
It has rich bio-diversity.
ECOSYSTEM OF ATMOSPHERE:
A thin layer of air, aerosols and gases surrounding earth surface and held towards it by gravity.
Nitrogen (N2) and oxygen (O2) comprises of nearly 99% of clean, dry air and remaining gases are mostly inert and constitutes about 1% of atmosphere.
Composition of Atmosphere.
Nitrogen (N2) (78.09%)
Oxygen (O2) (20.95%)
Argon (Ar) (0.93%)
Carbon dioxide (CO2) (0.03%)
Hydrogen (H2) (0.00005%)
other gases (0.00006%)
Most important and densest of all the layers. (2/3 of matter
More than 99% of water uapor moisture is locate
It has almost 75% air therefore weather, cydon anticyclones etc are occurs.
Important layer for global climate.
This layer is free from dust particles hence this layer is ideal for flying of jet aircraft
At 25km height the ozone layer is concertate ozone sphere is also called as chromospheres because most of the chemical activity takes place.
It is chemical active layer and meteoric activity
Temperature with height hence coldest layer of atmosphere.
Ionic state with electrically charged layer
Temperature due to absorption of solar radiation by ionised particles.
Due to electric charge radio waves gets reflected and long distance terrestrial radio communication system on earth came to exist hence its a “communication
Food and energy is passed through series of populations in an ecosystem. Food chain form essentially due to food habits of different organic species.
Population of different species of organisms are connected in an ecosystem through a chain of food habets or relationship. These sequential connections in chain are generally called as “FOOD CHAIN”.
The different levels in the chains are called as Trophic Level. Different species of organisms in ecosystem at different trophic levels are connected through a food chain. Food and Energy is transferred from one trophic level to another. The loss in the energy releases as heat into environment or is used in respiration process. At the maximum, there can be 4 – 5 trophic levels.
TYPES OF FOOD CHAINS:
Grazing Food Chain
Detritus Food Chain.
GRAZING FOOD CHAIN:
This food chain starts with autotrophs from autotrophs food energy is transferred through herbivorous to carnivorous.
Terrestrial (Grazing Food Chain):
Grass – Rabbit – Fox – Wolf – Tiger
Grass – Grasshopper – Shrew – Hawk
Plant – Butterfly – Frog – Snake – Hawk
AQUATIC (GRAZING FOOD CHAIN)
Phytoplankton – Zooplankton – Perch Fish – Bass Fish – Man
Phytoplankton – Zooplankton – Small Fish – Big Fish — Shark.