Environment

E — WASTE

E-waste is not hazardous if it is stocked in safe storage or recycled by scientific methods or transported from one place to the other in parts or in totality in the formal sector. The e-waste can be considered hazardous if recycled by primitive methods

Survey was carried out by the Central Pollution Control Board (CPCB) during 2005

In India, among top ten cities; Mumbai ranks first in generating e-waste followed by Delhi, Bangalore, Chennai, Kolkata, Ahmadabad, Hyderabad, Pune, Surat and Nagpur.

 

SOLID WASTE

the discarded (abandoned or considered waste-like) materials

does not include solid or dissolved materials in domestic sewage, or

solid or dissolved materials in irrigation return flows or industrial discharges0

Conventional plastics have been associated with reproductive problems in both humans and wildlife.

Dioxin (highly carcinogenic and toxic) by-product of the manufacturing process is one of the chemicals believed to be passed on through breast milk to the nursing infant.

Burning of plastics, especially PVC releases this dioxin and also furan into the  atmosphere.

Pyrolysis-It is a process of combustion in absence of oxygen or the material burnt under controlled atmosphere of oxygen. It is an alternative to incineration. The gas and liquid thus obtained can be used as fuels.

 

Waste Minimization Circles (WMC)

helps Small and Medium Industrial Clusters in waste minimization in their industrial plants.  assisted by the World Bank with the Ministry of Environment and Forests acting   as the nodal ministry.  being implemented with the assistance of National   Productivity Council (NPC), New Delhi.

aims to realise the objectives of the Policy Statement for Abatement of Pollution (1992), which states that the government should educate citizens about environmental risks, the economic and health dangers of resource degradation and the real economic cost of natural resources.

BIOREMEDIATION

the use of microorganisms (bacteria and fungi) to degrade the environmental contaminants into less toxic forms.

Phytoremediation

is use of plants to remove contaminants from soil and water .

Rhizofiltration

• a water remediation technique that involves the uptake of contaminants by plant roots.
• used to reduce contamination in natural wetlands and estuary areas.

 

ENVIRONMENTAL IMPACT ASSESSMENT

Notification on Environmental Impact Assessment (EIA) of developmental

projects 1994 under the provisions of Environment (Protection) Act, 1986 making EIA  mandatory for 29 categories of developmental projects. One more item was added to the list in January, 2000. environmental impact assessment statutory for 30 activities

Environment Impact Assessment Notification of 2006 has categorized the developmental projects  in two categories, i.e., Category A and Category B

Ministry of Environment & Forests

‘Category A’ projects are appraised at national level by expert appraisal committee

India has constituted the State Level Environment Impact Assessment Authority (SEIAA) and State Level Expert Appraisal Committee (SEAC)  to decentralize the environmental clearance process

The objective of EIA is to foresee and address potential environmental problems/  concerns at an early stage of project planning and design.

 

 

The EIA notification establishes four stages for obtaining Environmental Clearance.

1. Screening
2. Scoping and consideration of alternatives Baseline data collection
3. Impact prediction
4. Assessment of alternatives, delineation of mitigation measures and environmental impact statement
5. Public hearing
6. Environment Management Plan Decision making
7. Monitoring the clearance conditions

Screening- It is only for Categories B

Screening Criteria are based upon:

• Scales of investment; •       Type of development; and, •      Location of development

B1 Categories project require Environmental Impact Assessment while B2 category projects are exempted from EIA.

State Level Expert Appraisal Committee determine about project categories

Climate Change

 

• It is the long term change in the statistical distribution of weather patterns over periods of time
• Though it has been happening naturally for millions of years, in recent years it has accelerated due to anthropogenic causes and has been causing global warming.
• UNFCCC defines climate change as – “a change of climate which is attributed directly or indirectly to human activitythat alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods”

 

Climate Change Mitigation

• Alternative Energy sources
  • Renewable energy
  • Nuclear Power
  • Reduce the carbon intensity of fossil fuels
• Energy efficiency and conservation
  • Transport and urban planning
  • Building design
  • Reforestation and avoid deforestation
  • Eliminating waste methane
• Geoengineering
  • Greenhouse gas remediation
    • Biomass
    • Carbon air capture
    • Carbon capture and storage
  • Societal control
    • Population
    • Sustainable life-style

 

 

defined as ‘an addition or excessive addition of certain materials to the physical environment (water, air and lands), making it less fit or unfit for life’.

Pollutants are the materials or factors, which cause adverse effect on the natural quality of any component of the environment.

Classifications

1. According to the form in which they persist after release into the environment.

• Primary pollutants: These persist in the form in which they are added to the environment e.g. DDT, plastic.
• Secondary Pollutants: These are formed by interaction among the primary pollutants. For example, peroxyacetyl nitrate (PAN) is formed by the interaction of nitrogen oxides and hydrocarbons.

2. According to their existence in nature.

• Quantitative Pollutants: These occur in nature and become pollutant when their concentration reaches beyond a threshold level. E.g. carbon dioxide, nitrogen oxide.
• Qualitative Pollutants: These do not occur in nature and are man-made. E.g. fungicides, herbicides, DDT etc.

3. According to their nature of disposal.

• Biodegradable Pollutants: Waste products, which are degraded by microbial action. E.g. sewage.
• Non-biodegradable Pollutants: Pollutants, which are not decomposed by microbial action. E.g. plastics, glass, DDT, salts of heavy metals, radioactive substances etc

4. According to origin

• Natural
• Anthropogenic

 

AIR POLLUTION

aggravated because of four developments:

Increasing traffic, growing cities, rapid economic development, and industrialization

contamination of air by the discharge of harmful substances

 

Major air pollutants and their sources

1. Carbon monoxide (CO)

• It is a colourless, odourless gas that is produced by the incomplete burning of carbon – based fuels including petrol, diesel, and wood.
• It is also produced from the combustion of natural and synthetic products such as cigarettes.
• It lowers the amount of oxygen that enters our blood. It can slow our reflexes and make us confused and sleepy.

2. Carbon dioxide (CO2)

principle greenhouse gas

3. Chloroflorocarbons (CFC)

• gases that are released mainly fromair-conditioning systems and refrigeration.
• When released into the air, CFCs rise to the stratosphere, where they come in contact with few other gases, which lead to a reduction of the ozone layer that protects the earth from the harmful ultraviolet rays of the sun.

 

4. Lead

present in petrol, diesel, lead batteries, paints, hair dye products, etc.

affects children in particular. cause nervous system damage and digestive problems and, in some cases, cause cancer.

 

5. Ozone

• occurs naturally in the upper layers of the atmosphere.
• at-the ground level, it is a pollutant with highly toxic effects.
• Vehicles and industries are the major source of ground-level ozone emissions.
• Ozone makes our eyes itch, burn, and water. It lowers our resistance to cold and pneumonia.

 

6. Nitrogen oxide (Nox)

• causes smog and acid rain. It is produced from burning fuels including petrol, diesel, and coal.
• Nitrogen oxide can make children susceptible to respiratory diseases in winters.

 

7. Suspended particulate matter (SPM)

• consists of solids in the air in the form of smoke, dust, and vapour that can remain suspended for extended periods
• The finer of these particles when breathed in can lodge in our lungs and cause lung damage and respiratory problems.

 

8. Sulphur dioxide (S02)

• a gas produced from burning coal, mainly in thermal power plants.
• Some industrial processes, such as production of paper and smelting of metals, produce sulphur dioxide.
• a major contributor to smog and acid rain.
• Sulphur dioxide can lead to lung diseases

 

9. Smog

• a combination of the words fog and smoke. Smog is a condition of fog that had soot or smoke in it.
• interaction of sunlight with certain chemicals in the atmosphere.
• primary components of photochemical smog is ozone.
• Ozone is formed through a complex reaction involving hydrocarbons, nitrogen oxides, and sunlight. It is formed when pollutants released from gasoline, diesel- powered vehicles and oil-based solvents react with heat and sunlight from biofuels, the four most serious pollutants are particulates, carbon monoxide, polycyclic organic matter, and formaldehyde

 

Pollutants

1. i) Volatile organic compounds

The main indoor sources are perfumes, hair sprays, furniture polish, glues, air

fresheners, moth repellents, wood preservatives, and other products.

 

1. ii) Biological pollutants

It includes pollen from plants, mite, and hair from pets, fungi, parasites, and some bacteria.

iii) Formaldehyde

Mainly from carpets, particle boards, and insulation foam. It causes irritation to the eyes and nose and allergies.

1. iv) Radon

It is a gas that is emitted naturally by the soil. Due to modern houses having poor ventilation, it is confined inside the house and causes lung cancers.

 

Fly Ash

Ash is produced whenever combustion of solid material takes place.

Composition

1. Aluminium silicate (in.large amounts)
2. silicon dioxide (Si02) and
3. Calcium oxide (Ca0).

Fly ash particles are oxide rich and consist of silica, alumina, oxides of iron, calcium, and magnesium and toxic heavy metals like lead, arsenic, cobalt, and coppers

 

Policy measures of MoEF:

• The Ministry of Environment and Forests vide its notification in 2009, has made it mandatory to use Fly Ash based products in all construction projects, road embankment works and low lying land filling works within 100 kms radius of Thermal Power Station.
• To use Fly Ash in mine filling activities within 50 kms radius of Thermal Power Stations.
• Arresters: These are used to separate particulate matters from contaminated air.
• Scrubbers: These are used to clean air for both dusts and gases by passing it through a dry or wet packing material.

Government Initiatives

(1) National Air Quality Monitoring Programme

In India, the Central Pollution Control Board (CPCB) has been executing a nationwide programme of ambient air quality monitoring known as National Air Quality Monitoring

Programme (NAMP).

The National Air Quality Monitoring Programme (NAMP) is undertaken in India

(i) to determine status and trends of ambient air quality;

(ii) to ascertain the compliance of NAAQS;

(iii) to identify non-attainment cities;

(iv) to understand the natural process of cleaning in the atmosphere; and

(v) to undertake preventive and corrective measures.

Annual average concentration of SOx levels are within the prescribed National Ambient

Air Quality Standards (NAAQS).

National Ambient Air Quality Standards (NAAQS) were notified in the year 1982, duly revised in 1994 based on health criteria and land uses .

The NAAQS have been revisited and revised in November 2009 for 12 pollutants, which include. sulphur dioxide (S02), nitrogen dioxide (NO2), particulate matter having size less than 10 micron

(PM10),particulate matter having size less than 2.5micron (PM2.5), ozone, lead, carbon monoxide (CO), arsenic, nickel, benzene, ammonia, and. Benzopyrene.

WATER POLLUTION

Addition of certain substances to the water such as organic, inorganic,

biological, radiological, heat, which degrades the quality of water so that it

becomes unfit for use.

Putrescibility is the process of decomposition of organic matter present in water by microorganisms using oxygen.

Water having DO (dissolved oxygen)  content below 8.0 mg/L may be

considered as contaminated.  Water having DO content below. 4.0 mg/L is

considered to be highly polluted.

Water pollution by organic wastes is measured in terms of Biochemical Oxygen Demand-(BOD). BOD is the amount of dissolved oxygen needed by bacteria in decomposing the organic wastes present in water.

Chemical oxygen demand (COD) is a slightly better mode used to measure pollution load in water. It is the measure of oxygen equivalent of the requirement of oxidation of total organic matter (i.e. biodegradable and non- biodegradable) present in water.

A cripling deformity called Minamata disease due to consumption of fish captured from mercury contaminated Minamata Bay.

Water contaminated with cadmium can cause itai itai disease also called ouch-ouch disease (a painful disease of bones and joints) and cancer of lungs and liver.

The compounds of lead cause anaemia, headache, loss of muscle power and bluish line around the gum

Excess nitrate in drinking water reacts with hemoglobin to form non -functional met haemoglobin, and impairs oxygen transport.  This condition  is  called methaemoglobinemia or blue baby syndrome.

Over exploitation of ground water may lead to leaching of arsenic from soil and rock sources and contaminate ground water.  Chronic exposure to arsenic causes black foot disease. It also causes diarrhoea,-peripheral neuritis, hyperkerotosis and also   lung and skin cancer.

SOIL POLLUTION

Industrial waste includes chemicals such as mercury, lead, copper, zinc, cadmium, cynides, thiocynates, chromates, acids, alkalies, organic substances etc

Four R’s: Refuse, Reduce, Reuse, and Recycle

NOISE POLLUTION

Sound is measured in decibels (dB). An increase of about 10 dB is approximately double the increase in loudness.

A person’s hearing can be damaged if exposed to noise levels over 75 dB over a prolonged period of time.

The World Health Organization recommends that the sound level indoors should be less than 30 dB.

Ambient Noise Level Monitoring –   Noise Pollution (Control and Regulation) Rules, 2000 define ambient noise levels for various areas as follows-

1. Industrial Area—75DB to 70Db (Day time-6am to 10pm and night time 10pm to 6am ..75 is day time and 70 is night time)
2. Commercial Area–65 to 55
3. Residential Area–55 to 45
4. Silence Zone– 50  to 40

• The Government of India on Mar 2011 launched a Real time Ambient Noise Monitoring Network.
• Under this network, in phase- I, five Remote Noise Monitoring Terminals each have been installed in different noise zones in seven metros (Delhi, Hyderabad, Kolkata, Mumbai, Bangalore, Chennai and Lucknow).

In Phase II another 35 monitoring stations will be installed in the same seven cities.

Phase III will cover installing 90 stations in 18 other cities.

Phase-III cities are Kanpur, Pune, Surat, Ahmedabad,  Nagpur, Jaipur,  Indore,

Bhopal, Ludhiana, Guwahati, Dehradun, Thiruvananthpuram, Bhubaneswar,

Patna, Gandhinagar, Ranchi, Amritsar and Raipur.

Silence Zone is an area comprising not less than 100 metres around hospitals, educational institutions, courts, religious places or any other t area declared as such by a competent authority.

 

 

RADIO ACTIVE POLLUTION

Non-ionising radiations affect only those components which absorb them and have low penetrability.   They include short-wave radiations such as ultraviolet rays, which forms a part of solar radiation. Sunburns is due to these radiation Ionising radiations have high penetration power & cause breakage of macro molecules

They include X-rays, cosmic rays and atomic radiations -(radiations emitted by radioactive elements

Alpha particles, can be blocked by a piece of paper and human skin.

Beta particles can penetrate through skin, while can be blocked by some pieces of glass and metal.

Gamma rays can penetrate easily to human skin and damage cells on its way through, reaching far, and can only be blocked by a very thick, strong, massive piece of concrete radium-224, uranium-238, thorium-232, potassium-40, carbon-14, etc.

The nuclear arms use uranium-235 and plutonium-239 for fission and hydrogen or lithium as fusion material

The radio nuclides with long half-time are the chief source of environmental radioactive pollution.

 

• located where river meets the sea.
• the most productive water bodies in the world
• The complete salinity range from 0-35 ppt is seen from the head (river end) to the mouth (sea end) of an estuary
• Coastal lakes which have their connection with the sea through small openings are better known as lagoons or backwaters acting as a natural water filter

 

Estuary Formation:

grouped into four geomorphic categories based on the physical processes responsible for their formation:

1) rising sea level; (2) movement of sand and sandbars; (3) glacial processes; and (4) tectonic processes.

India Estuarine Ecosystem

The Country has 14 major, 44 medium and 162 minor rivers drains into the sea through various estuaries.

Major estuaries occur in the Bay of Bengal.

Most of the India’s major estuaries occur on the east coast. In contrast, the estuaries on the west coast are smaller.

 

MANGROVES

are the characteristic littoral plant formation of tropical and subtropical sheltered coastlines.

are trees and bushes growing below the high water level of spring tides which exhibits remarkable capacity for salt water tolerance.

basically evergreen land plants growing on sheltered shores, typically on tidal flats, deltas, estuaries, bays, creeks and the barrier islands. require high solar radiation and have the ability to absorb fresh water from saline/ brackish water. produces pneumatophores (blind roots) to overcome respiration problem in the anaerobic soil conditions

• Leaves are thick and contain salt secreting glands.
• exhibit viviparity mode of reproduction. i.e. SeedS germinate in the tree itself (before falling to the ground). This is an adaptative medianiSintoovercome the problem of germination in Saline water.
• crystals of salt on the back of the leaves; others block absorption of salt at their roots

The mangroves of Sundarbans are the largest single block of tidal holophytic mangroves of the world. famous for the Royal Bengal Tiger and crocodiles.

The mangroves of Bhitarkanika (Orissa), which is the second largest in the Indian sub continent, harbour high concentration of typical mangrove species and high genetic diversity have (additional) special roots such as prop roots, pneumatophores  which help to impede water flow and thereby enhance the deposition of sediment in areas (where it is already occurring), stabilize the coastal shores, provide breeding ground for fishes. protects coastal lands from tsunami, hurricanes:and floods release oxygen back to the atmosphere, along with a little methane gas

 

CORAL REEFS

Coral is actually a living animal.

has a symbiotic relationship (each gives something to the other and gets something back in return) With ‘zooxanthellae’ microscopic algae which live on coral [i.e. instead of living on the sea  floor, the algae lives up on the coral which is closer to the ocean surface and so that the algae gets lots of light.

The tissues of corals themselves are actually not the beautiful colors of the coral reef, but are instead clear (white). The corals receive their  coloration from the zooxanthellae living within their tissues.

• There are two types of corals: hard corals and soft corals, such as sea fans and gorgonians. Only hard corals build reefs.
• The builders of coral reefs are tiny animals called polyps. As these polyps thrive, grew, then die, they leave their limestone (calcium carbonate) skeletons behind. The limestone is colonized by new polyps.
• found in tropical and sub-tropical water, there are also deep water corals in colder regions
• The United Nations Environment Programme reports that there are more cold water coral reefs worldwide than tropical reefs.
• There are only about 6 different coral species associated in building with these reefs.
• The largest cold-water coral reef is the Rost ‘Reef off Norway occur in shallow tropical areas where the sea water is clean, clear and warm.
• one of the most productive and complex coastal ecosystems with high biological diversity classified depending on their locations into fringing, patch, barrier and atoll.
• The fringing reefs are contiguous with the shore and they are the most common – by occurring reef form, found in Andamans.
• Patch reefs are isolated and discontinuous patches, lying shoreward of offshore reef structures as seen in the Palk bay, Gulf of Mannar and Gulf of Katchchh.
• Barrier reefs are linear offshore reef structures that run parallel to coastlines and arise from submerged shelf platforms. The water body between the reef and the shore is termed as lagoon. Barrier reefs are seen in Nicobar and Lakshadweep.
• Atolls are circular or semi-circular reefs that arise from subsiding sea floor platforms as coral reef building keeps ahead of subsidence. The examples are the atolls of Lakshadweep and Nicobar.
• Among the four major reef areas of India, Andaman and Nicobar Islands are found to be very rich in species diversity followed by the Lakshadweep Islands, the Gulf of Mannar and finally the Gulf of Kachchh.

 

 

Coral Bleaching

 

Bleaching, or the paling of coral colour occurs; when (i) the densities

of zooxanthellae decline and (ii) the concentration of photosynthetic pigments within the zooxanthellae fall.

Ecological causes of coral bleaching

• Temperature (Major Cause)
• Sub aerial Exposure-Sudden exposure of reef flat corals to the atmosphere during events such as extreme low tides, ENSO-related sea level drops or tectonic uplift can potentially induce bleaching.
• Sedimentation
• Fresh Water Dilution
• Inorganic Nutrients(e.g. ammonia and nitrate)
• Xenobiotics -Zooxanthellae loss occurs during exposure of coral to elevated concentrations of various chemical contaminants, such as Cu, herbicides and oil.
• Epizootics

 

KEY INITIATIVES TO PROTECT MARINE AND COASTAL ENVIRONMENTS

 

1. Coastal Ocean Monitoring and Prediction System (COMAPS)

• Being implemented from 1991. Assesses the health of coastal waters and facilitates management of pollution-related issues
• Programme was restructured and modified in 2000 2001 to include pollution monitoring; liaison, regulation and legislation; and consultancy services.

2.Land Ocean Interactions in the Coastal Zone (LOICZ)

 

• Launched in 1995. Investigates the effects of global change on the coastal zone
• Aims to develop, on a scientific basis, the integrated management of coastal environments

3. Integrated Coastal and Marine Area Management (ICMAM)

• Launched in 1998
• Aims at integrated management of coastal and marine areas.
• Model plans for Chennai, Goa and Gulf of Kutch being prepared

4. Society of  Integrated Coastal Management (SICOM)

• Launched in 2010
• Major national initiative to protect coastal ecosystems
• A professional body with experts in various aspects of coastal science and management

5. Institutions for Coastal Management

• The Notification on Coastal Regulation Zone (CRZ), 1991 (as amended from time to time) aims at protecting coastal stretches in India.
• India has created institutional mechanisms such as National Coastal Zone Management
• Authority (NCZMA) and State Coastal Zone Management Authority (SCZMA) for enforcement and monitoring of the CRZ Notification.
• These authorities have been delegated powers under Section 5 of the Environmental (Protection) Act, 1986 to take various measures for protecting and improving the quality-of the coastal environment and preventing, abating  and controlling environmental pollution in coastal areas.

 

 

Areas of marsh, fen, peatland/water, whether natural (or) artificial, permanent (or) temporary with water that is static (or) flowing, fresh, brackish (or) salt, including areas of marine

water the depth of which at low tide does not exceed 6 mtrs.

Wetlands Classification-

1. Inland wetland-

a)Natural- Lakes / Ponds, Ox-bow Lakes, Waterlogged, Swamp/marsh

1. b) Manmade- Reservoirs Tank, Ash pond
2. Costal Wetland-
3. A) Natural- Coral reef, Tidal flat, Mangroves, Salt marsh, Estuary, Lagoon, Creek,

Backwater, Bay

b)-manmade -• Salt pans, Aquculture

Functions of Wetlands-

• Habitat to aquatic flora and fauna, birds
• Filtration of sediments and nutrients from surface water,
• Nutrients recycling, Water purification Floods mitigation,
• Ground water recharging, Buffer shorelines against erosion,
• Genetic reservoir for various species of plants(rice)
• the National Lake Conservation Programme (NLCP) considers lakes as standing water
• bodies which have a minimum water depth of 3 m, generally cover a water spread of more than ten hectares, and have no or very little aquatic vegetation.
• Wetlands (generally less than 3 m deep over most of their area) are usually rich in nutrients (derived from surroundings and their sediments) and have .abundant growth of aquatic macrophytes

India’s Wetland

Wetlands occupy 18.4% of the country’s area of which 70% are under paddy cultivation.

Inland wetlands >Costal Wetlands

 

National Wetlands Conservation Programme (NWCP)

• NWCP was implemented in the year 1985-86.
• Under the programme, 115 wetlands have been identified by the Ministry which require urgent conservation and management interventions.

Aim

• Conservation of wetlands to prevent their further degradation and ensuring their wise
• use for the benefit of local communities and overall conservation of biodiversity.

Objectives

• to lay down policy guidelines for conservation and management of wetlands in the country.
• to provide financial assistance for undertaking intensive conservation measures in the identified wetlands
• The Central Government is responsible for overall coordination of wetland
• conservation programmes and initiatives at the international and national levels. It also provides guidelines, financial & technical assistance to state govt.
• State Governments/UT Administration are responsible for management of wetlands and implementation of the NWCP for ensuring their wise-use

 

Criteria for Identification of Wetlands of National Importance

Criteria for identification of wetlands of national importance under NWCP are same as those prescribed under the ‘Ramsar Convention on Wetlands’ and are as given below:

1. Sites containing representative, rare or unique wetland types

example of a natural or near-natural wetland type’ found within the appropriate biogeographic region.

2. Criteria based on species and ecological communities

• If it supports vulnerable, endangered, or critically endangered species; or
• threatened ecological communities.
• If it supports populations of plant and/or animal species important for maintaining the biological diversity of a particular biogeographic region.
• If it supports plant and/or animal species at a critical stage in their life cycles, or provides refuge during adverse conditions.

 

3. Specific criteria based on water birds

• If it regularly supports 20,000 or more water birds.
• If it regularly supports 1% of the individuals in a population of one species or subspecies of waterbirds.

 

4. Specific criteria based on fish

• If it supports a significant proportion of indigenous fish subspecies, species or families, life-history stages,  species  interactions  and/or  populations  that  are representative of wetland benefits and/or values and thereby contributes to global biological diversity.
• If it is an important source of food for fishes, spawning ground, nursery and/or migration path on which fish stocks, either within the wetland or elsewhere, depend.

5. Specific criteria based on water/life and culture

• If it is an important source of food and water resource, increased possibilities for recreation  and eco-tourism, improved scenic values, educational opportunities, conservation of cultural heritage (historic or religious sites)

 

 

Any – body of standing water, generally large enough in area and depth, irrespective of its hydrology, ecology, and other characteristics is generally known as lake.

Ageing of Lakes

The nutrient enrichment of the lakes promotes the growth of algae, aquatic plants and various fauna. This process is known as natural eutrophication.

Similar nutrient enrichment of lakes at an accelerated rate is caused by human activities and the consequent ageing phenomenon is known as ‘cultural eutrophication’.

In India, natural lakes (relatively few) mostly ile in the Himalayan region, the floodplains of Indus, Ganga and Brahmaputra.

Lake ‘Sudarshan’ in Gujarat’s Girnar area was perhaps the oldest man-made lake in India, dating back to 300 BC.

Lakes are also classified on the basis of their water chemistry. Based-on the levels of salinity, they are known as Freshwater, Brackish or Saline lakes (similar to that of classification of aquatic ecosystem).

On the basis of their nutrient content, they are categorized as Oligotrophic (very low nutrients), Mesotrophic (moderate nutrients) and Eutrophic (highly nutrient rich).

Removal of the nutrients from a lake

• Flushing with nutrient-poor waters.
• Deep water abstraction.
• On-site P-elimination by flocculation/flotation with water backflow, or floating Plant
• NESSIE with adsorbents.
• On-site algae removal by filters and P-adsorbers.
• 0n-site algae skimming and separator thickening.
• Artificial mixing / Destratification (permanent or intermittent).
• Harvest of fishes and macrophytes.
• Sludge removal

EUTROPHICATION

a syndrome of ecosystem, response to the addition of artificial or natural substances such as nitrates and phosphates through fertilizer, sewage, etc that fertilize the aquatic ecosystem.

The growth of green algae which we see in the lake surface layer is the physical identification of an Eutrophication.

Some algae and blue-green bacteria thrive on the excess ions and a population explosion covers almost entire surface layer is known as algal bloom.  Nitrogen testing is a technique to find the optimum amount of fertilizer required for crop plants. It will reduce the amount of nitrogen lost to the surrounding area.

 

 

HARMFUL ALGAL BLOOMS

Algae or phytoplankton are microscopic organisms that can be found naturally in coastal waters. They are major producers of oxygen and food for many of the animals that live in these waters.

Algal blooms can be any color, but the most common ones are red or brown.

Most algal blooms are not harmful but some produce toxins and do affect fish, birds, marine mammals and humans.

Use of algae

Most species of algae or phytoplankton serve as the energy producers at the base of the food web, without which higher life on this planet would not exist.

Why Red Tide is a misnomer?

“Red Tide” is a common name for such a phenomenon where certain

phytoplankton species contain pigments and “bloom” such that the human eye perceives the water to be discoloured.

Blooms can appear greenish, brown, and even reddish orange depending upon the type of organism, the type of water, and the concentration of the organisms.

The term “red tide” is thus a misnomer because blooms are not always red, they are not associated with tides, they are usually not harmful, and some species can be harmful or dangerous at low cell concentrations that do not discolour the water.

What are the causes of these blooms?

Two common causes are nutrient enrichment and warm waters.

 

Fresh water ecosystems- The salt content of fresh bodies is very low, always less than 5 ppt  (parts per thousand). E.g lakes, ponds, pools, springs, streams, and rivers

Marine ecosystems – the water bodies containing salt concentration equal to or above that of sea water (i.e., 35 ppt or above). E.g shallow seas and open ocean   Brackish water ecosystems- these water bodies have salt content in between 5 to 35 ppt. e.g. estuaries, salt marshes, mangrove swamps and forests.

 

AQUATIC ORGANISMS

The aquatic organisms are classified on the basis Of their one of occurrence and their ability to cross these zones. can be classified on the basis of their life form or location into five groups

1. Neuston:

These are unattached organisms which live at the air-water interface such as floating plants, etc.

Some organisms spend most of their lives on top of the air-water interface such as water striders, while others spend most of their time just beneath the air-water interface and obtain most of their food within the water.

E.g., beetles and back-swimmers.

2. Periphyton:

These are organisms which remain attached to stems and leaves of rooted plants or substances emerging above the bottom mud such as sessile algae and their associated group of animals.

3. Plankton

This group includes both microscopic plants like algae (phytoplankton) and

animals like crustaceans and protozoans (zooplankton) found in all aquatic

ecosysteins, except certain swift moving waters

The locomotory power of the planktons is limited so that their distribution is

controlled, largely, by currents in the aquatic ecosystems.

4. Nekton:

This group contains animals which are  swimmers.

The nektons are relatively large and powerful as they have to overcome the water currents.

5. Benthos:

The benthic organisms are those found living in the bottom of the water mass.

Practically every aquatic ecosystem contains well developed benthos

Factors Limiting the Productivity of Aquatic Habitats

1. Sunlight :

Sunlight penetration rapidly diminishes as it passes down the column of water.

The depth to which light penetrates a lake determines the extent of plant distribution.

Based on light penetration and plant distribution they are classified as photic and aphotic zones

Photic zone:

It is the upper layer of the aquatic ecosystems, up to which light penetrates and within which photosynthetic activity is confined.

The depth of this zone depends on the transparency of water.

photic (or .”euphotic”) zone is the lighted and usually well-mixed portion that extends from the lake surface down to where the light level is 1% of that at the surface.

Aphotic zone:

The lower layers of the aquatic ecosystems, where light penetration and plant growth are restricted forms the aphotic zone.

Only respiration activity takes place.(photic-both respiration and photosynthesis take place )

Aphotic zone is positioned below the littoral and photic zones to bottom of the lake where light levels are too low for photosynthesis.

This deep, unlit region is also known as the profundal zone.

Dissolved oxygen:

Oxygen enters the aquatic ecosystem through the air water interface and by the photosynthetic. average concentration of dissolved oxygen as 10 parts per million by weight.

Dissolved oxygen escapes the water body through air-water interface and through respiration of organisms (fish, decomposers, zooplanktons, etc )

The amount of dissolved oxygen retained in water is also influenced by temperature.

Other limiting factors which influence on aquatic productivity are

Transparency:

Transparency affects the extent of light penetration.

Suspended particulate matters such as clay, silt, phytoplankton, etc make the water turbidity. Consequently it limits the extent of light penetration and the photosynthetic activity in a significant way.

Temperature:

The water temperature changes less rapidly than the temperature of air because water has a considerably higher specific heat than air.

Since water temperatures are less subject to change, the aquatic organisms have narrow temperature tolerance limit.

 

Deserts are formed in regions with less than 25 cm of annual rainfall, .or sometimes in hot regions where there is more rainfall, but unevenly distributed in the annual cycle.

Lack’ of rain in the mid latitude is often due to stable high pressure zones; deserts in temperate regions often lie in “rain shadows”, that is where high mountains block off moisture from the seas.

The climate:of these biomes is modified by altitUde and latitude. At greater distance from the equator the deSerts are cold and hot near equator and tropics.

As the large volume of water passes through the irrigation system, salts may be left behind that will gradually accumulate over the years until they become limiting, unless means of avoiding this difficulty are devised

Adaptations

(i)  These plants conserve water by following methods:

They are mostly shrubs. Leaves are absent or reduced in size.

Leaves and stem are succulent and water storing.

In some plants even the stem contains chlorophyll for photosynthesis.

Root system is well developed and spread over large area.

The annuals wherever present germinate, bloom and reproduce only during the short rainy season, and not in summer and winter.

(ii) The animals are physiologically and behaviorally adapted to desert conditions.

They are fast runners.

They are nocturnal in habit to avoid the sun’s heat during day time.

They conserve water by excreting concentrated urine.

Animals and birds usually have long legs to keep the body away from the hot ground.

Lizards are mostly insectivorous and can live without drinking water for several days.

Herbivorous animals get sufficient water from the seeds which they eat.

Mammals as a group are poorly adapted to  deserts

Indian Desert — Thar desert (hot)

The climate of this region is characterised by excessive drought, the rainfall being scanty and , irregular.

The winter rains of northern India rarely penetrate into the region.

The proper desert plants may be divided into two main groups.

1. i) depending directly upon on rain and
2. ii) those depending on the presence of subterranean water.

The first group consists of two types:

the ‘ephemera’s’ and the rain perennials’.

The ephemera’s are delicate annuals, apparently free from any xerophilous adaptations, having slender stems and root-systems and often large Flowers.

They appear almost immediately after rain, develop flowers and fruits in an incredibly short   time, and die as soon as the surface layer of the soil dries up.

The rain perennials are visible above the ground only during the rainy season, but have a perennial underground stem.

The second group – depending on the presence of subterranean water

By far the largest number of indigenous plants are capable of absorbing water from deep below the surface of the ground by means of a well-developed root system, the main part of which generally consists of a slender, woody tap root of extraordinary length.

Generally, various other xerophilous adaptations are resorted to such as reduced leaves, thick hairy growth, succulence, coatings of wax, thick cuticle, protected stomata, etc., all having for  their object of reduction of transpiration.

 

Fauna

It is home to some of India’s most magnificent grasslands and sanctuary for a charismatic bird, the Great Indian Bustard. Among the mammal fauna, the blackbuck, wild ass, chinkara, caracal, Sandgrouse and desert fox inhabit the open plains, grasslands, and saline depressions.

The nesting ground of Flamingoes and the only known population of Asiatic wild Ass lies in the remote part of Great Rarm, Gujarat.

It is the migration flyway used by cranes and flamingos.

Some endemic flora species of Thar Desert includes Calligonum Polygonoides, Prosopis cineraria, Tecomella undulate, Cenchrus biflorus and Sueda fruticosa , etc

 

Cold Desert/ Temperate Desert

Cold desert of India include areas of ladak, leh and kargil of kashmir and spiti valley of Himachal  Pradesh and some parts of northern Uttaranchal and Sikkim. Lies in rain shadow of Himalaya Oak, pine, deodar, birch and rhododendron are the important trees and bushes found there. Major  animal include yaks, dwarf cows, and goats.

Severe arid conditions – Dry Atmosphere

Mean annual rainfall less than 400mm

Soil type – sandy to sandy loam , Soil pH – neutral to slight alkaline.

Soil nutrient – Poor organic matter content ,low water retention capacity

Bio-diversity

Cold desert is the home of highly adaptive, rare endangered fauna, such as

Asiatic Ibex, Tibetan Argali, Ladakh Uriyal, Bharal, Tibetan Antelope (chiru),

Tibetan Gazelle, Wild Yak, Snow Leopard, Brown Bear, Tibetan Wolf, Wild

Dog and Tibetan Wild Ass (‘Kiang’ a close relative of the Indian wild ass) ,

Woolly hare, Black Necked  Crane, etc.

India as a signatory to United Nations Convention to Combat Desertification

(UNCCD) has submitted four National Reports to UNCCD

in the years 2000, 2002, 2006 and 2010

Some of the major programmes currently implemented that address issues related to land degradation and desertification is:-

1. Integrated Watershed Management Programme (IWMP),
2. National Afforestation Programme (NAP),
3. National Mission for Green India (GIM),
4. The Mahatma Gandhi National Rural Employment Guarantee Scheme
5. (MGNREGS),
6. Soil Conservation in the Catchment of River Valley Project and Flood Prone River,
7. National Watershed Development Project for Rainfed Areas (NWDPRA),
8. Desert Development Programme (DDP)
9. Fodder and Feed Development Scheme-component of Grassland Development including
10. Grass Reserves, Command Area Development and Water Management (CADWM)  programme etc

 

 

 

found where rainfall is about 25-75 cm per year, not enough to support a forest, but more than that of a true desert.

vegetation formations that are generally found in temperate climates.

In India, they are found mainly in the high Himalayas. The rest of India’s grasslands aremainly composed of steppes and savannas.

Steppe formations occupy large areas of sandy and saline soil; in western Rajasthan, where the climate is semi-arid,

The major difference between steppes and savannas is that all the forage in the steppe is  provided only during the brief wet season whereas in the savannas forage is largely from grasses that not only grow during the wet season but also from the  smaller amount of regrowth in the dry season.

 

Types of Grasslands

1. semi-arid zone (The Sehima-dichanthium type)

It covers the northern portion of Gujarat, Rajasthan (excluding Aravallis), western Uttar Pradesh, Delhi and Punjab.

The topography is broken up by hill spurs and sand dunes.

senegal, Calotropis gigantia, Cassia auriculata, Prosopis cineraria, Salvadora oloides and zizyphus Nummularia which make the savanna rangeland look like scrub.

2. dry sub humid zone (The Dichanthium- cenchrus-lasitrrus type)

It covers the whole of peninsular India (except Nilgiri).

The thorny bushes are Acacia catechu, Mimosa, Zizyphus (ber) and sometimes fleshy Euphorbia, along with low trees of Anogeissus latifolia, Soymida febrifuga and other deciduous species.

Sehima (grass)is more prevalent on gravel and the cover maybe 27%. Dichanthium (grass) flourishes on level soils and may cover 80% of the ground.

3)  moist subhumid zone(The Phragmities- sacchrum-imperata type)

It covers the Ganga alluvial plain in Northern India.

The topography is level, low lying and ill-drained.

Bothriochloa pertusa, Cypodon dactylon and     Dichanthium annulatum are found in transition zones.

The common trees and shrubs are Acacia arabica, hogeissus, latifolia, Butea monosperma,

Phoenic sylvestris and Zizyphus nummularia.

Some of these are replaced by Borassus sp in the palm savannas especially near Sunderbans.

4) The Themeda – Arundinella type

This extends to the humid montane regions and moist sub-humid axeas of Assam, Manipur,West Bengal, Uttar Pradesh, Punjab, Himachal Pradesh and. Jammu and Kashmir.

The savanna is derived from the humid forests on account of shifting cultivation and sheep grazing.

Indian Grasslands and Fodder Research Institute, Jhansi and Central Arid Zone Research institute, Jodhpur

Role of fire

fire plays, an important role in the management  of grasslands.

Under moist conditions fire favours grass over trees, whereas in dry conditions fire is often necessary to maintain grasslands against the invasion of desert shrubs.

Burning increases the forage yields, e.g. Cynodon daotylon

 

 

Forest ecosystem includes a complex assemblage of different kinds of biotic communities. Optimum conditions such as temperature and ground moisture are responsible for the establishment of forest communities.

Forests may be evergreen or deciduous which are distinguished on the basis of leaf into broad-leafed or needle leafed coniferous forests in the case of temperate areas. classified into three major categories: coniferous forest, temperate forest and tropical forest.

All these forest biomes are generally arranged on a gradient from north to south latitude or from high to lower altitude

 

Coniferous forest (boreal forest):

Cold regions with high rainfall, strong seasonal climates with long winters and short summers

evergreen plant species such as Spruce, fir and pine trees, etc and by animals such as the lynx, wolf, bear, red fox, porcupine, squirrel, and amphibians like Hyla, Rana, etc.

Boreal forest soils are characterized by thin podozols and are rather poor. Both because, the weathering of rocks proceeds slowly in cold environments and because the litter derived from conifer needle (leaf  is decomposed very slowly and is not rich in nutrients.

These soils are acidic and are mineral deficient.

This is due to movement of large amount of water through the soil, without a significant counter-upward movement of evaporation, essential soluble nutrients like calcium, nitrogen and potassium which are leached sometimes beyond the reach of roots. This process leaves no alkaline oriented cations to encounter the organic acids of the accumulating litter.

The productivity and community stability of a boreal forest are lower than those of any other forest ecosystem.

Temperate deciduous forest:

The temperate forests are characterised by a moderate climate and broad-leafed deciduous trees, which shed their leaves in fall, are bare over winter and grow new foliage in the spring.

The precipitation is fairly uniform throughout.

Soils of temperate forests are podozolic and fairly deep.

Temperate evergreen forest:

Parts of the world that have Mediterranean type of Climate are characterised by warm, dry summers and cool, moist winters. low broad leafed evergreen trees.

Fire is an important hazardous factor in this ecosystem and the adaptation of the plants enable them to regenerate quickly after being burnt.

Temperate rain forests:

seasonality with regard to temperature and rainfall

Rainfall is high, and fog may be very heavy. It is the important source of water than rainfall itself

The biotic diversity of temperate rain forests is high as compared to other temperate forest.

the diversity of plants and animals is much low as compared to the tropical rainforest.

 

Tropical rain forests:

 

Near the equator.

Among the most diverse and rich communities on the earth.

Both temperature and humidity remain high and more or less uniform.

The annual rainfall exceeds 200 cm and is generally distributed throughout the year.

The flora is highly diversified The extreme dense vegetation of the tropical rain  forests remains vertically stratified with tall trees often covered with vines, creepers,   lianas, epiphytic orchids and bromeliads.

The lowest layer is an understory of trees,  shrubs, herbs, like ferns and palms.

Soil of tropical rainforests are red latosols, and they are very thick

Tropical seasonal forests:

also known as monsoon forest occur in regions where total annual rainfall is very high but segregated into pronounced wet and dry periods.

This kind of forest is found in South East Asia, central and south America, northern Australia, western Africa and tropical islands of the pacific as well as in India.

Subtropical rain forests:

Broad-leaved evergreen subtropical rain forests are found in regions of fairly high rainfall but less temperature differences between winter and summer

Epiphytes are common here.

Animal life of subtropical forest is very similar to that of tropical rainforests.

 

INDIAN FOREST TYPES

Forest types in India are classified by Champion and Seth into sixteen types.

 

Tropical Wet evergreen forests

are found along the Western Ghats, the Nicobar and Andaman Islands and all  along the north-eastern region.

It is characterized by tall, straight evergreen trees.

The trees in this forest form a tier pattern:

Beautiful fern of various colours and different varieties of orchids grow on the trunks of the trees.

Among the following States, which one has the most suitable climatic conditions for the cultivation of a large variety of orchids with minimum cost of production, and can develop

Tropical Semi-evergreen forests

found in the Western Ghats, Andaman and Nicobar Islands, and the Eastern

Himalayas.

Such forests have a mixture of the wet evergreen trees and the moist

deciduous trees. The forest is dense

Tropical Moist deciduous forests

found throughout India except in the western and the north -western regions.

The trees are tall, have broad trunks, branching trunks and roots to hold them firmly to the ground.

These forests are dominated by sal and teak, along with mango, bamboo, and rosewood.

Littoral and swamp

found along the Andaman and Nicobar Islands and the delta area of the Ganga and the Brahmaputra.

They have roots that consist of soft tissue so that the plant can breathe in the water.

Tropical Dry deciduous forest

The northern part of the country except in the North-East. It is also found in Madhya Pradesh, Gujarat, Andhra Pradesh, Karnataka, and Tamil Nadu. The canopy, of the trees does not normally exceed 25 metres.

The common trees are the sal, a variety of acacia, and bamboo.

Tropical Thorn forests

This type is found in areas with black soil: North, West, Central, and South India. The trees do not grow beyond 10 metres. Spurge, caper, and cactus are typical of this region.

Tropical Dry evergreen forest

Dry evergreens are found along Tamil Nadu Andhra Pradesh and Karnataka coast. It is mainly hard-leaved evergreen trees with fragrant flowers, along with a few  deciduous trees.

Sub-tropical Broad-leaved forests

Broad-leaved forests are found in the Eastern Himalayas and the Western Ghats, along the Silent Valley.

There is a marked difference in the form of vegetation in the two areas.

In the Silent Valley, the  poonspar, cinnamon, rhododendron, and fragrant grass are predominant.

In the Eastern Himalayas, the flora has been badly affected by the shifting cultivation and forest fires.

There are oak, alder, chestnut, birch, and cherry trees. There are a large variety of orchids, bamboo and creepers.

Sub-tropical Pine forests

found in Shivalik Hills, Western and Central Himalayas, Khasi, Naga, and Manipur Hills.

The trees predominantly found in these areas are the chir, oak, rhododendion, and   pine as well as sal, amla, and laburnum are found in the lower regions.

 

Sub-tropical Dry evergreen forests

hot and dry season and a cold winter. It generally has evergreen trees with shining

leaves that have a varnished look.

found in the Shivalik Hills and foothills of the Himalayas up to a height of 1000 metres.

Montane Wet temperate forests

In the North, found in the region to the east of Nepal into Arunachal Pradesh, receiving a minimum rainfall of 2000 mm. In the North, there are three layers of    forests: the higher layer has mainly coniferous, the middle layer has deciduous trees such as the oak and the lowest layer is covered by rhododendron and champa.

In the South, it is found in parts of the Niligiri Hills, the higher reaches of Kerala.

The forests in  the northern region are denser than in the South. Rhododendrons and a

variety of ground flora can be found here.

Himalayan Moist temperate Forest

This type spreads from the Western Himalayas to the Eastern Himalayas. The trees

found in the western section are broad-leaved oak, brown oak, walnut,

rhododendron,

Eastern Himalayas, the rainfall is much heavier and therefore the vegetation is also more lush and dense. There are a large variety of broad-leaved trees, ferri, and  bamboo.

Himalayan Dry temperate Forest

This type is found in Lahul, Kinnaur, Sikkim, and other parts of the Himalayas.

There are predominantly coniferous trees, along with broad-leaved trees such as the oak, maple, and ash. At higher elevation, fir, juniper, deodar, and chilgoza are found.

 

Sub alpine forest

Sub alpine forests extend from Kashmir to Arunachal Pradesh between 2900 to 3500 metres.

In the Western Himalayas, the vegetation consists mainly of juniper, hododendron, willow, and black currant.

In the eastern parts, red fir, black juniper, birch, and larch are the common trees.

Due to heavy rainfall and high humidity the timberline in this part is higher than that in the West.

Rhododendron of many species covers the hills in these parts.

Moist Alpine scrub

Moist alpines are found all along the Himalayas and on the higher hills near the Myanmar border. It has a low scrub, dense evergreen forest, consisting

mainly of rhododendron and birch. Mosses and ferns cover the ground in patches. This region receives heavy snowfall.

Dry alpine scrub

Dry alpines are found from about 3000 metres to about 4900 metres. Dwarf plants predominate, mainly the black juniper, the drooping juniper, honeysuckle, and willow.

 

 

The interrelations between organisms and environment on the land constitute “Terrestrial Ecology”.

The most important limiting factors of the terrestrial ecosystems are moisture and temperature.

 

 

TUNDRA

The word tundra means a “barren land” since they are found where environmental conditions are very severe. There are two types of tundra- arctic and alpine.

Distribution:

Arctic tundra extends as a continuous belt below the polar ice cap and above the tree line in the northern hemisphere. It occupies the northern fringe of Canada, Alaska, European Russia, Siberia and island group of Arctic Ocean.

On the south pole, tundra is very small since most of it is covered by ocean .

Alpine tundra occurs at high mountains above the tree line. Since mountains are found at all latitudes therefore alpine tundra shows day and night temperature variations.

Flora and fauna:

Typical vegetation of arctic tundra is cotton grass, sedges, dwarf heath, willows, birches and lichens.

Animals of tundra are reindeer, musk ox, arctic hare, caribous, lemmings and squirrel.

They are protected from chillness by the presence of thick cuticle and epidermal hair.

Mammals of the tundra region have large body size and small tail and ear to avoid the loss of heat from the surface.

The body is covered with fur for insulation.