Monday, September 30, 2013

Disaster management - Floods

Increased rainfall or rapid snow melting causes more flow of water in the streams. This excess water flow in a stream covering the adjacent land is called a flood. Floodplain is defined in terms of a flood frequency. Flood frequency is referred as 10-year flood, 100-year flood, etc. A 10-year flood at any point in a stream is that discharge of water which may be expected to occur on average once in 10 years. Floodplains are generally fertile, flat and easily formed.
Heavy rainfall
Construction of buildings in a flood plain
Removing vegetation
Paving roads and parking areas

Erosion of top soil and vegetation
Damage and loss to land, house and property
Spread of endemic waterborne diseases
Interruption of basic facilities of community such as highways, railways, telephone, electricity and day-to-day essentials
Silting of reservoirs and dams

Construction of flood control dam
Deepening, widening and straightening of streams
Lining of streams
Banning of construction of buildings in floodplains
Converting flood-plains into wildlife habitat, parks, and recreation areas.

Disaster management - Landslides

Landslides occur when mass of earth material move downward. It is also called mass wasting or mass movement. A sudden landslide occurs when unconsolidated sediments of a hillside are saturated by rainfall or water logging.
Many landslides take place in coincidence with earthquakes. The most common form of landslides are earthquake induced landslides or more specifically rock falls and slides of rock fragments that form on steep slopes.
The size of area affected by earthquake induced landslides depends on the magnitude of the earthquake, its focal depth, the topography and geologic conditions near the causative fault, the amplitude, frequency, composition and duration of ground shaking.

Avoid construction activity in landslide occurring areas.
Reducing slope of hilly side
Stabilising the slope portion
Increasing plantation of deep rooted vegetation on the slope.

Disaster management - Earthquakes

An earthquake occurs when rocks break and slip along a fault in the earth. Earthquakes occur due to deformation of crust and upper mantle of the earth. Due to heating and cooling of the rock below these plates, movement of adjacently overlying plates and great stresses, deformation occurs. Tremendeous energy can build-up between neighbouring plates. If accumulated stress exceeds the strength of the rocks, the rocks break suddenly releasing the stored energy as an earthquake.
The earthquake releases energy in the form of waves that radiate from the epicenter in all directions. The 'p' wave or primary wave alternately compresses and expands material in the same direction it is travelling. This wave can move through solid rocks and fluids. These are the fastest waves. The 's' wave or secondary wave is slower and shake the ground up, down, back and forth perpendicular to the direction in which it is travelling. Surface waves follow both the 'P' and 'S' waves.
The magnitude of an earthquake is measured in richter scale. The richter scale is logarithmic.


Liquefaction of ground
Ground displacement

There is virtually no technique to control the occurrence of earthquake. However, certain preventive measures can be taken to minimise the damage.
Minimizing development activity (especially construction, mining, construction of dams and reservoirs) in areas known to be active seismic zones.
Continuously monitoring seismic activity using 'seismographs' and alerting people regarding any recorded disturbance in advance.

Wednesday, September 18, 2013

Forest conservation act, 1980

Forest conservation act, 1980
This act provides conservation of forests and related aspects. This act covers all types

of forests such as reserved forest, protected forest and any forested land. This act was

enacted in 1980 and it aims to arrest deforestation.
Important features of this act are:
-The reserved forests shall not be diverted or dereserved without prior permission of the

central government.
-The land that has been notified or registered or forest land may not be used for non-

forest purposes.
-Any illegal non-forest activity within a forest area can be immediately stopped under

the act.
Important amendments:
-Forest departments are forbidden to assign any forest land for re-afforestation
-Clearance of any forest land of naturally grown trees for the purpose of re-

afforestation is forbidden.
-Diversion of forest land for non-forest uses is a cognizable offence and the violator is

punishable under law.

Wildlife Protection Act, 1972

Wildlife Protection Act, 1972
This act is aimed to protect and preserve wildlife. Wildlife refers to all animals and

plants that are not domesticated. India has a rich wildlife heritage. It has 350 species

of mammals, 1200 species of birds and around 20,000 known species of insects. Some of

them are listed as 'endangered species' in wildlife protection act.
Wildlife is an integral part of our ecology and plays an essential role in its

functioning. Decline in wildlife is mostly due to human actions. Animals have been hunted

since ages for their skins, furs, feathers, ivory, etc. Wildlife populations are

monitored regularly and management strategies are formulated to protect them.

The important features of this act are:
-This act covers the rights and non-rights of forest dwellers
-It provides restricted grazing in sanctuaries but prohibits in national parks
-It also prohibits collection of non-timber forest
-The rights of forest dwellers recognised by forest policy of 1988 are taken away by the

amended wildlife act of 1991.

Water (prevention and control of pollution) act, 1974

Water act, 1974
Objectives of this act:
-To prevent and control water pollution
-To maintain or restore the wholesomeness of water
To establish boards for the prevention and control of water pollution
To confer on and assign to the boards, the power and functions relating to the above mentioned.

Salient features of this act:
-Establishment of central and state boards for pollution control
-Provision of joint boards for two or more states
-Prohibition of the use of streams and wells for the disposal of pollutants.
-Consent of pollution control board to open new outlets and discharges into streams and wells.


Air (prevention and control of pollution) act, 1981

Objectives of this act are:
-Prevention, control and abatement of air pollution
-Maintaining the quality of air
-Establishing boards for prevention and control of air pollution

Important features of this act:
-Central board may lay down standards for quality of air
-Central board coordinates and settles disputes between state boards in addition to providing technical assistance and guidance to state boards
-State boards may lay down standards for emissions of air pollutants from industrial units, automobiles or other sources
-State boards should collect and disseminate information related to air pollution and function as inspectorates of air pollution
-State boards should examine manufacturing process and pollution control equipment to verify if they meet standards prescribed.
-State board can advise the state government to declare heavily polluted areas as pollution control areas and advise avoidance of burning waste products that can increase air pollution.
-The directions of central board are mandatory on state boards.
-Operation of Industrial unit is prohibited in heavily polluted areas without the consent of the central board.
-Violation of this law is punishable with imprisonment a term which may extend to three months or fine upto Rs. 10,000 or both.

Environment Protection Act, 1986


-To protect and improve air, water and land environment
-To prevent hazards to all living creatures and properties
-To maintain a pleasant relationship between human beings and their environment.

Important features of this act:
-This act empowers the government to lay down procedures and safeguards for prevention of accidents that cause pollution and remedial measures if an accident occurs.
-The government has the authority to close/prohibit or regulate any industry or its operation if violation of the provisions of the act occur.
-Any person who fails to comply or contravenes any provision of the act is punishable with imprisonment for a term extending upto five years or a fine upto one lakh rupees or both.
-An additional fine of Rs.5000 per day may be imposed for entire period of violation of rules.
-The act fixes the liability on the person who is directly in-charge unless it is proved that the offence was committed without his/her knowledge or consent.
-This act empowers the officer of central government to inspect the site and collect samples of air, water,  soil or other material for testing.

This act is the most comprehensive legislation with powers for central government to act directly without interference from regulatory authorities or agencies.

Important questions-ii

Write briefly about the biogeographical zones in India
There are 10 biogeographical zones in India. They are briefly described below:
  1. Trans-Himmalayas: The Trans-Himmalayas is an extension of the Tibetean plateau.
  2. Himalayas: The Himalayas form the northern boundary of India. The Himalayas comprises a diverse range of biotic provinces and biomes.
  3. Desert: Three kinds of deserts are found in India. They are, Desert of western Rajasthan, Desert of Gujarat and the high altitude cold desert of Jammu & Kashmir and Himachal Pradesh
  4. Semi-arid: This zone lies in between the desert and the Deccan plateau.
  5. Western Ghats: This is a mountain range that runs along the western coast of India. This ghat section covers a diverse range of biotic provinces and biomes.
  6. Deccan Plateau: It is a large triangular plateau south of Narmada valley. The Satpura mountains cover the north side, western ghats and eastern ghats cover the west and east sides respectively. The plateau slopes towards east. The plateau is covered with deciduous vegetation.
  7. Gangetic plain: The Gangetic plains cover from south of the Himalayas to north of tropic of cancer. These plains were formed by the Ganges river system and are relatively homogenous. The famous 'sunderban' forests are located in these plains.
  8. North-east India: The plains and non-himalayan hill ranges of northeastern India fall in this zone. This zone is filled with a wide variety of vegetation.
  9. Islands: The Andaman and Nicobar islands in the bay-of-bengal is a group of 300 small and large islands. Mostly tribes live in Nicobar islands. These islands have a highly diverse set of biomes.
  10. Coasts: The Indian subcontinent is blessed with a long coastline on the east and west with distinct differences between the two.

Write notes on threats to biodiversity
Biodiversity has evolved simultaneously with human culture. Man has met the changing needs and pressures of increasing population by applying knowledge and skills. People have hunted, fished and gathered species for food, fuel, fiber and shelter thereby eliminating competing or threatening species.
Activities mentioned above destroys and depletes the basis of an ecosystem (genes and species). As a result, mankind loses food, medicine and industrial products in the present and future.
According to the World Conservation Union's Red List, the threat to biodiversity is due to human activity particularly, habitat destruction.
Few of the Major biodiversity threats are listed below:
  1. Habitat destruction
  2. Extension of agriculture
  3. Filling-up of wetlands
  4. Conversion of rich biodiversity site for human settlement and industrial development
  5. Destruction of coastal areas
  6. Uncontrolled commercial exploitation
One of the primary causes of loss of biodiversity is habitat destruction. The main causes for the same are listed below:
  1. Agricultural activities
  2. Extraction including mining, fishing, logging and harvesting
  3. Developmental activities including human settlement, industry and associated infrastructure
Millions of hectares of forest area is lost due to illegal encroachment of forest land. Forest land is also lost due to construction of river valley projects, introduction of transmission lines and roads, etc. Change in forest composition and quality can lead to decline in primary food species for wildlife.
Fragmentation is the process of division of a population into several small groups. Habitat loss and fragmentation leads to formation of isolated, small and scattered populations which are susceptible to inbreeding, depression, high infant mortality and eventually possible extinction.
Introduced species are responsible for many recorded species extinctions, especially on islands. In these isolated ecosystems, a new predator, competitor or pathogen can rapidly endanger species that did not evolve simultaneously with the newcomer.
Several forest, fisheries and wildlife resources have been over-exploited to the point of extinction. A few cases are mentioned below as a point in case. Poaching of wild animals (The Tiger, Elephant, Rhinoceros) has resulted in their extinction. Population pressures adversely affect the forest resources on which the local communities depend while having a negative impact on biodiversity.
Pollutants strain ecosystems. Contamination affects the food chain. A point in case is marine pollution from non-point sources that ruins estuaries and coastal seas throughout the world. Pesticides used to control agricultural pests have shown to negatively impact birds due to severe air pollution in Spain.

Write about energy flow in an ecosystem
Energy is an essential requirement for all living organisms. Solar energy is the only source of energy for the Earth. Solar energy is transformed to chemical energy by photosynthesis in plants (primary producers). Though lot of sunlight falls on plants, only 1% of this is utilized for photosynthesis.
Some amount of energy is used by the plant for growth and the remaining is transferred to consumers by the process of eating. Thus energy enters the ecosystem through photosynthesis and passes through different feeding levels (tropic levels)
The flow of energy through an ecosystem follows two laws of thermodynamics:
  1. First law of thermodynamics states that “energy can neither be created nor destroyed, but can be converted from one form to another.” Ex: Energy for an ecosystem comes from the sun. It is absorbed by plants where it is converted and stored as chemical energy or solar energy is converted into chemical energy.
  2. Second law of thermodynamics states that “whenever energy is transformed, there is a loss of energy through the release of heat.” Ex: Whenever energy is transferred between tropic levels, loss of energy takes place through respiration, running, hunting, etc.
Describe aquatic ecosystem
Aquatic ecosystem deals with water bodies. Types of organisms found in aquatic environment depend on salinity of water (salt content).
Types of aquatic life zones:
  1. Fresh water life zones (Ponds, Streams, Rivers, Lakes)
  2. Salt water life zones. (Oceans and Estuaries)
Pond ecosystems
  1. Pond is temporary, only seasonal
  2. It is a stagnant freshwater body
  3. It is easily polluted due to limited amount of water.
Structure and function
Examples of abiotic components are temperature, light, water, organic and inorganic compounds.
Biotic components are comprised of
i.              Producers: These include green photosynthetic organisms. They are of two types:
                        a)         Phytoplankton and
                        b)         Microphytes
Phytoplankton are microscopic aquatic plants, which float freely on the surface of water. Examples of phytoplankton are Algae, Volvox, Pandorina, Anabena and Cosmarium.
Microphytes are large floating plants and submerged plants. Examples of microphytes are hydrilla, jussiaea, wolfia and demna.

            ii.         Consumers:
                        Primary consumers (Zooplanktons): These are microscopic animals that freely float on                               the surface of water. Zooplanktons are found along with phytoplanktons which they eat.                           Examples of zooplanktons are planktons, very small fish, ciliates, flagellates and                            protozoans.
                        Secondary consumers (Carnivores): They feed on zooplanktons. Examples of carnivores                are insects like water beetles and small fish.
                        Tertiary consumers: They feed on smaller fish. Examples of tertiary consumers are large                 fish like game fish.
iii.        Decomposers: They decompose dead plant and animal matter and their nutrients are          released and reused by green plants. Examples of decomposers are fungi, bacteria and         flagellates.
Lake ecosystems:
i.                                Lakes are natural shallow water bodies
ii.                              Lakes are supplied with water from rainfall, melting snow and streams.
iii.                            Lake is a permanent water body with large water resources.
iv.                            Lakes help in irrigation and supplying drinking water.

Structure and function of Lake Ecosystem: The abiotic components of lake ecosystems consist of temperature, light, proteins, lipids, turbidity, oxygen and carbon-dioxide.
The biotic components are classified into:
                 i.               Producers:             Green plants (Floating, Submerged and amphibious). Examples of                                 producers are phytoplanktons, algae and flagellates.
                  ii.            Consumers:            Primary consumers are zooplanktons like ciliates, protozoans, etc that                                        feed on phytoplanktons.
Secondary consumers  are carnivores like insects and smaller fishes that feed on zooplanktons
                                       Tertiary consumers feed on smaller fish. Examples are large fish and                                                            game fish
iii.     Decomposers:        Decomposers decompose dead plants and animals. Examples of                                                                  decomposers are bacteria, fungi and actinomycetes.

River Ecosystem:
                          i.            It is fresh water and freely flowing water system
                        ii.            Flowing water allows mixing of water resulting in higher dissolved oxygen
                      iii.            River deposits large amount of nutrients.
Structure and function of River Ecosystem: The abiotic components of river ecosystems are temperature, light, pH, nutrients, organic and inorganic compounds.
Biotic components are classified into:
                          i.            Producers:          Phytoplankton, Algae, water grasses, aquatic grasses and other                                               amphibious plants.
                        ii.            Consumers:        Primary consumers feed on phytoplanktons. Examples are water insects,                                snails and fishes.
Secondary consumers are feed on primary consumers.
iii.     Decomposers:        Decomposers decompose dead plants and animals. Examples of                                                                  decomposers are bacteria, fungi and actinomycetes.

Ocean ecosystems:
  1. Oceans occupy a large surface area and made up of saline water.
  2. Commercial activities are carried out in oceans.
  3. Oceans are rich in biodiversity
  4. Oceans moderate the temperature of the earth.
Structure and function of Ocean Ecosystems:
The abiotic components of ocean ecosystems are temperature, light, NaCl, K, Calcium and Magnesium salts and alkalinity.
The biotic components comprise of
  1. Producers: Phytoplanktons (diatoms, unicellular algae, etc) and marine plants (sea weeds, chlorophyceal, phaeophyceae)
  2. Consumers: They are heterotrophic macroconsumers which depend upon producers for their nutrition.
    1. Primary consumers or herbivores feed on producers (Ex: Crustaceans, Mollusks, Fish
    2. Secondary consumers or carnivores feed on herbivores (Ex: Herring, Mackerel, etc)
    3. Tertiary consumers are the top consumers and feed on small fishes. (Ex: Cod, Haddock, etc)
  3. Decomposers decompose dead organic matter. (Ex: Bacteria and fungi)

Estuarine ecosystem:
  1. Estuaries are transition zones that are strongly affected by tides of the sea.
  2. Water in estuaries change periodically
  3. The organisms in estuaries have a wide tolerance
  4. Salinity remains highest in summer and lowest in winter.
Structure and function of Estuarine Ecosystems:
Abiotic components of estuarine ecosystems are temperature, pH, sodium and potassium salts and nutrients.
Biotic components consist of
  1. Producers: Examples are marsh grasses, seaweeds, seagrasses and phytoplankton.
  2. Consumers: Examples are Oysters, Crabs, Seabirds, and small fishes
  3. Decomposers: Examples are Bacteria, fungi and actinomycetes.

Important questions-i

Write in detail about structure and function of an ecosystem.
Ecology is the study of ecosystems and ecosystem is the basic functional unit of ecology. A group of
organisms interacting amongst themselves and with the environment is called ecosystem. An ecosystem
is a community of different species interacting with each other and their non-living environment
thereby exchanging energy and matter.
Structure of an ecosystem shows the relationship between abiotic and biotic components.
All the living members of an ecosystem form the biotic community. Ex: Plants (producers), animals
(consumers) and microorganisms (decomposers).
The non-living components (physical and chemical) of an ecosystem collectively form the abiotic
community. Ex: Climate, Soil, Energy, Nutrients, Water and Air.
Physical components are necessary for the growth and maintenance of living components of the
Chemical components are the source for essential nutrients. They consist of organic substances
(protein, lipids, carbohydrate) and inorganic substances (Al, Co, Zn, Cu-micro elements C, H, O, P, N,
P, K-macro elements)
Function of an ecosystem is of three types:
Primary function: The primary function of all ecosystems is to manufacture starch (photosynthesis)
Secondary function: The secondary function of all ecosystems is to distribute energy to all the
consumers in the form of food.
Tertiary function: All living organisms die and these dead systems are decomposed to initiate the
third system of ecosystems called “cycling”.

Define and differentiate between food chain and food web with a diagram
A food chain is a model that shows the flow of energy from autotrophs to a series of organisms in an
environment. The energy that flows can be different for each food chain. The food chain describes the
flow of food from one organism to the next thereby giving energy to the organism digesting the food.
The number of steps involved in a food chain is restricted to four or five. The energy available
decreases with each step. The energy loss takes place in the form of heat. The three types of food
chains are:
Grazing food chain,
Detritus food chain and
Parasitic food chain.
All food chains start with the sun.
The interlocking pattern of various food chains in an ecosystem is known as food web. In a food web
many food chains are interconnected. In a food web different types of organisms are connected at
different tropic levels resulting in several opportunities of eating and being eaten at each tropic level.
An important difference between food chain and food web is that food chain is linear and this implies
that if one species becomes extinct, the species in the subsequent tropic levels are also affected.
However, in a food web, if one species is affected, there is no serious effect on other tropic levels as
there are several options available at each tropic level.
Enumerate the value of biodiversity
The value of biodiversity is classified into:
Direct values and
Indirect Values
Direct value of biodiversity: Biodiversity has direct value in the form of consumption in agriculture,
medicine and industry. Among all plant species identified as fit for human consumption, only 150 have
been cultivated on a large scale. Two types of direct values are:
Consumptive use value and
Productive use value
Consumptive use value is the value placed on nature's products that are consumed directly without
passing through a market. Consumptive use value is not included in national income accounts.
Consumptive use value benefits the communities closest to the resource if harvested sustainably with
proper management. Product examples of consumptive use value are firewood, food and game meat.
Productive use value refers to products that are commercially harvested and sold in a market. Its value
is estimated at production end after addition of cost and value. The productive use value has a major
impact on national economy. Product examples of productive use value are timber, fish, honey,
mushrooms, game meat sold in markets and medicinal plants.
Biodiversity has indirect value since it provides economic benefits without being harvested. Direct
value of biodiversity is derived from its indirect value. Indirect value of biodiversity is listed below:
Non consumptive use value
Option value
Existence value and
Information value
Non consumptive use value refers to nature's functions and services. Examples of this are
photosynthesis by plants that provides support system for other species, maintenance of water cycle,
regulating climate, production and protection of soil, absorption and breakdown of pollutants,
recreational, aesthetic, socio-cultural, scientific, educational, spiritual and historic values of natural
Option value refers to the indirect value of a species potential to produce economic benefits to the
society in the future.
Existence value is the value gained from continuous knowledge of existence. An example in this
context is the expense incurred by the administration of various countries to develop techniques in
order to prevent a species from becoming extinct (Giant Panda, Blue whale, White tiger, etc).
Information value refers to the educational, scientific, aesthetic and tourism values of biodiversity in an

What are the types of biodiversity conservation
With the rapid increase of human population and resulting expansion of man's needs coupled with
scientific knowledge led to over-exploitation of natural resources. Eventually, conservation of
biological diversity became a global concern. This involves influencing behaviour of people at local
level through education, at the national level through policy work and awareness programs.
International corporations should ensure that their business do not contribute to further loss of
The two main types of biodiversity conservation are:
In-situ conservation and
Ex-situ conservation
In-situ conservation is defined as the conservation of genetic resources through their maintenance
within natural or man-made ecosystems in which they occur.
In-situ conservation effort is setting-up of protection areas. This technique is the best conservation
strategy. However, its implementation is sometimes unfeasible. National Parks, Sanctuaries and
Biosphere reserves are some types of in-situ conservation.
Ex-situ conservation is defined as conservation made outside the habitat of an ecosystem. In case the
habitat of rare or endangered species is destroyed, ex-situ conservation is the only means of conserving
a species. It also provides a back-up solution to in-situ conservation projects. A few examples of ex-situ
conservation are seed banks, botanical gardens, pollen storage, tissue culture and genetic engineering



Biodiversity or biological diversity is a term used to describe life on earth.  It refers to the wide variety of ecosystems and living organisms (plants, animals, their habitats and their genes).

Biodiversity is the foundation of life on earth. It is essential for the functioning of ecosystems. We depend on biodiversity for our security and health. It affects our social relations and gives us freedom and choice.

Biodiversity is extremely complex, dynamic and varied. Biodiversity occurs both on land and in water. Biodiversity is difficult to measure precisely. There are many measures of biodiversity. Species richness (number of species in a given area) is an important metric concerning the diversity of life. 

Genetic diversity- a population with many different genotypes or genotype combinations
Species diversity- a biome or ecosystem with many differerent species
Ecosystem diversity- a biome with many different ecosystems

Genetic diversity is how much genetic variation there is in a population. Genetic diversity is related to the ability of a species to adapt to a changing environment.

Species diversity is a measure of the diversity within an ecological community that incorporates both species richness (the number of species in a community) and the evenness of species abundances. Species diversity is one component of the concept of biodiversity.

Ecosystem diversity is the global or continental distribution of ecosystems of different types. Ecosystem diversity is conditioned by vegetation, climate, biogeography and influence of human beings. Eg: Forest
ecosystem, Desert ecosystem, Tundra ecosystem, Coastal ecosystem, etc.

Value of biodiversity is classified into:
             I.      Direct values and
          II.      Indirect values

Direct value of biodiversity:
Biodiversity has direct consumptive use in
  1. Agriculture
  2. Medicine and
  3. Industry.

Two types of direct values are
  1. Consumptive use value and
  2. Productive use value

Consumptive use value is placed on nature’s products that are consumed directly, without passing through a market or they are harvested and consumed directly.
Ex: Firewood, Food and Meat (from hunting in the wild)

The following are the disadvantages associated with consumptive use value
  1. Over-exploitation of wildlife in developing countries.
  2. Loss of traditional controls on hunting and
  3. Loss of wildlife populations at productive levels.

Productive use value refers to products that are commercially harvested and sold in a market. Its value is estimated at the production end, rather than the retail end. Productive use value is the value of biological resources reflected in national income accounts and may have a major impact on the national economy.
Ex: Timber, Fish, Honey, Mushroom, Fruits, Meat and Medicinal plants sold in a market have productive use value.

Indirect value of biodiversity:
The indirect effects of biodiversity are intangible and difficult to quantify. These are described below:
  1. Social and cultural value: Few plants and animals are considered sacred and worshipped in India. Ex: Tulsi, Peepal, Cow, Snake, etc. Wild life in the forest is given cultural value. Ex: Tiger is the national animal, Peacock is the national bird and Lotus is the national flower.
  2. Ethical value: In order to conserve biodiversity, this ethical value is laid down saying, “All life forms must be preserved”. This value is linked to human existence as biodiversity is directly related to the survival of the human race. Moreover, all species have a moral right to exist.
  3. Aesthetic value: This value is indicated by the pleasure we experience when we see a beautiful landscape. These landscapes also provide ample opportunities for recreational activity like bird watching, photography, etc. It promotes eco-tourism and generates revenue from zoological parks, botanical gardens, national parks, etc.
Ex: Ecotourism, etc.
  1. Option value: Option values are the unexplored or unknown potentials of biodiversity.
Ex: Medicinal plants and herbs play a very important growth in the economic growth of India.
  1. Environment service value: The most important benefit of biodiversity is maintenance of environment services including:
    1. Carbon dioxide fixation through photosynthesis
    2. Maintenance of essential nutrient (C, H, O, P, S) cycles
    3. Maintaining water cycle and recharging ground water
    4. Soil formation and protection from erosion
    5. Regulating climate by recycling moisture into the atmosphere
    6. Detoxification and decomposition of waste.

Monday, September 16, 2013

Concept of an Ecosystem

Concept of an ecosystem
An ecosystem is a region with a specific landscape form.
Ex: Forest, Grassland, Desert, Wetland or coastal area.
The nature of ecosystem depends on its geographical features.
Ex: Hills, Mountains, Coastal plains, Rivers, Plains or Islands.
The term “Ecosystem” was coined by A.G.Tansley in 1935. He defined the ecosystem as “the system
resulting from integration of all the living and non-living factors of the environment”.
Ecosystem is the basic functional unit in ecology. Ecosystem development is an autogenic process.
Ecosystem may also be defined as the interaction of biotic and abiotic components of the environment thereby exchanging matter and energy.