In this article we will discuss about:- 1. Meaning of Biodiversity 2. Importance of Biodiversity 3. Threat 4. Extinction of Species 5. Conservation.
Meaning of Biodiversity:
Biodiversity is the short form of biological diversity. It is the variability among the living organisms from all sources, including terrestrial, marine and other aquatic ecosystems and ecological complexes in which they are the part, and this includes diversity within species, between species and of the ecosystems. Biodiversity refers to the variety and variability among living organisms and the ecological complexes in which they occur.
It is the sum total of the diversity in the biosphere in terms of number, variety and variability of all living organisms. The term biodiversity was coined by Walter G. Rosen in 1985. A concise definition of biodiversity is “the totality of genes, species, and ecosystems in a region” (IUCN, UNEP 1992). Agrobiodiversity is the subset of biological diversity which is related to the agriculture. Thus agrobiodiversity is the diversity of the agricultural systems.
There are three hierarchical levels of biodiversity:
(1) Genetic Diversity:
The diversity in the genetic make-up of a species is known as genetic biodiversity. The minute differences found within a species i.e., between the varieties, races or strains are due to slight variations in the genetic organisation. These minute differences may be in shape, size, quality of the product, resistance to insect, pest and diseases etc.
A species with a large no. of races, strains or varieties is considered to be rich and diverse in genetic organisation. If a species has more genetic diversity, it would be better in the changed environment. Lower diversity in a species leads to uniformity (i.e., monoculture).
(2) Species Diversity:
A species is a group of organisms genetically so similar to each other that they can inter breed and produce fertile off-springs. A species is usually the unit of classification in most of the taxonomic works. Species are distinct units of diversity which play a specific role in an ecosystem. Species diversity refers to the variety of species within a region. The loss of one species has the consequences for the ecosystem.
(3) Community and Ecosystem Diversity:
A community is a group of populations of different species in a given area. It includes all the populations of plants, animals and microorganisms in that particular area. Depending largely upon the availability of abiotic resources and conditions of the environment on ecosystem develops its own characteristic community of living organism. Different types of forests, grassland, lakes, ponds, rivers etc., represent diverse ecosystems each with a characteristic biotic community.
India is one of the 17 mega diverse countries which together possess 60-70% of the world’s biodiversities. India ratified the international convention on Biodiversity (CBD) in 1994, and became a part of it. The CBD is an international legal instrument for promoting conservation and sustainable use of biological diversity taking into account the need to share cost and benefit between developed and developing countries and the ways and means to support innovation by local people. The 8th meeting of conference of the parties (COP) to the CBD was held in Curitiba, Brazil from 20-31 March, 2006.
A National Biodiversity Authority has been set up at Chennai vide Gazette notification dated 01.10.2003 under the Biological Diversity Act, 2002.
The 17 mega diverse countries are:
v) Costa Rica
vi) Democratic Republic of Congo
xvi) South Africa, and
These countries are rich in biological diversity and associated traditional knowledge have been formed the group of Like Minded Megadiverse Countries (LMMC). India was the president of LMMC for a period of two years from March 2004 to March 2006.
The Cartagena Protocol on biodiversity, the first international regulatory framework for safe transfer, handling and use of living modified organism (LMOs) was negotiated under the aegis of the convention on Biological Diversity.
India occupies nearly 2.5% of the global land mass but it has about 7.5% of the identified biological species.
India is one of the twelve mega-biodiversity countries of the world. On the basis of survey of about 2/3rd of the geographical area of the India the ministry of forest & environment reported (GOI, 2000) that India have about 45,000 plants and 77,000 animals species representing about 7% of world flora and 6.5% of the world fauna respectively representing about 6.5% of the global biodiversity.
About 5000 species of flowering plants belonging to 141 genera and 47 families had birth in India. Our country is a source of traditional crop varieties ranking first amongst the 12 regions of diversity of crop plants and 7th so far in the contribution of agricultural species. India is the origin place of 166 species of crop plants and 320 species of wild relatives of cultivated crops.
In India, there are three mega-endemic centres:
a) Eastern Himalayas:
1808 endemic plants from approximately 6000 species.
b) Western Himalayas:
1195 endemic plants from 5000 species.
c) Western Ghats:
1500 endemic plants from 4000 species.
Biodiversity loss is very severe in agro-ecosystems. Thousands of wild crop varieties have been replaced by a few hybrid species. This resulted in the loss of genetic resources. Indiscriminate use of agro-chemicals has reduced the microbial flora and fauna.
Importance of Biodiversity:
Diversity is the beauty of nature. Biodiversity is the source of food, medicines, pharmaceutical drugs, fibres, rubber, timber and many more.
There are three major importance of biodiversity for the human race:
(A) Biodiversity serves as valuable natural resources of our agriculture, livestock, forestry and fisheries. About 90% of all Indian medicines are obtained from plants.
Biodiversity in the wild form is useful to agriculture in two ways viz.:
(i) As a source of new crop.
(ii) As a source of material for breeding improved varieties.
(B) Biodiversity is essential for stable and healthy ecosystem. If there is a loss of a single or few species from a simple ecosystem, there would be catastrophic because of the lack of alternatives. Biodiversity serves as an effective instrument to ensure optimum utilization of abiotic resources. In the moist tropics of richest biodiversity, decomposition of organic matter and mineralization are very rapid and thus all the available nutrients are absorbed quickly.
(C) Biodiversity has the great aesthetic & cultural values. Examples of aesthetic values include ecotourism, bird watching, wild life, pet keeping, gardening etc.
Over-exploitation of natural resources due to increased never- ending human desires and sometimes natural calamities are the major causes for the loss in biodiversity.
These important factors are:
(1) Destruction of Habitat:
It is the primary reason for the loss of biodiversity. Population explosion, rapid industrialisation, felling of trees, urbanization, commercialisation of agriculture etc., are the various causes for the destruction of natural habitat of species.
In many countries, particularly on islands where human population density is high, most of the original habitats have .been destroyed. In tropical Asia, fully 65% of the wildlife habitat is loss of which 80% in India. The causal are the large industrial and commercial activities like mining, cattle ranching, fishing, forestry, plantation, agriculture, manufacturing and dam construction.
Pollution of various degrees disturbs the balanced ecosystem. Eutrophication (nutrient enrichment) due to water pollution drastically reduces the species diversity. The most subtle form of habitat degradation is environmental pollution due to pesticides, industrial chemicals & wastes, emission from factories & automobiles and sediment deposits from eroded hill sides.
(3) Natural Calamities:
Earthquakes, forest fires, volcanic eruptions, tsunamis, floods, drought, epidemics etc. Sometimes cause serious loss to the plant and animal life.
(4) Exotic Species:
Three main factors i.e. European colonisation, horticulture & agriculture, and accidental transport are responsible for introduction of exotic species. Sometimes exotic species have large impact especially in island ecosystems. Dodo, a flightless bird of Mauritius, was wiped out due to destruction of their eggs by pigs introduced in the country.
In 1859 introduction of European rabbit in the Australia by a farmer for game caused an ecological imbalance due to removal of biological control. Water hyacinth introduced in India now causes a serious threat to the aquatic species in lakes and ponds. Due to Lantana camera, indigenous plants are suppressed.
(5) Shifting cultivation/swidden Agriculture/Jhum cultivation.
Extinction of Species:
Extinction is the natural process where species have disappeared and new ones have evolved over the long geographical history of our earth.
There are three types of extinction processes:
(1) Natural Extinction:
With the change in environmental conditions, some species are disappeared and some are evolved according to the changed condition some species were lost in the geological past is categorised under natural background extinction.
(2) Mass Extinction:
There were several geological period of earth when a large number of species became extinct because of catastrophes. Such mass extinction occurs in millions of years.
(3) Anthropogenic Extinction:
Such extinction is due to never ending human desires which deplete biodiversity severely only because it occurs in a short period of time.
The characteristics of species susceptible to extinction are:
i) Large body size viz. Bengal tiger, lion, elephant.
ii) Small population size and low reproductive rate viz. Blue whale, giant panda.
iii) Feeding at high trophic levels in the food chain e.g. Bengal tiger, Bald eagle.
iv) Fixed migratory routes and habitat e.g. Blue whale, whooping crane.
v) Localised and narrow range of distribution e.g. woodland caribou, many island species.
The species which are threatened with extinction are categorised under:
a) Vulnerable species means such species are facing a high risk of extinction in the wild in the medium term future.
b) Endangered species means such species are facing a very high risk of extinction in the wild in the near future.
c) Critically endangered- such species are facing an extremely high risk of extinction in the wild in the immediate future.
d) Extinct in wild-when exhaustive surveys are failed to record such species in wild.
e) Extinct- when the last surviving individual has died.
Red Data Book:
The world conservation union (formerly called international union for the conservation of nature and natural resources IUCN) with headquarter at Gland, Switzerland, is the premier coordinating body for international conservation efforts.
The red data book published by the survival service commission of IUCN in 1970 listed the endangered species of plants and animals. According to this book, around 20,000 species are endangered all over the world. IUCN published the book ‘IUCN Plant Red Data Book’ in 1978 and the book ‘IUCN Red list of Threatened Animals’ in 1988.
According to IUCN (2000) 11,046 species of plants and animals are facing high risk of extinction. A rare flightless bird, Kago in New Caledonia, a primitive wild ox from southern Asia and the Orinoco River crocodile are near extinction. On a global basis, the IUCN estimated that about 10% of the world’s vascular plant species (i.e., 20000-25000 species) are threatened.
According to IUCN (1984, 1988), to highlight the legal status of rare species for the conservation purpose, there are five main conservation categories:
iii. Vulnerable species,
iv. Rare species which have small total no. of individuals, and
v. Insufficiently known species.
In India, the problem on threatened plants was first discussed in the 11th technical meeting of the IUCN in 1969. In 1980, the Botanical Survey of India (BSI) published a booklet named Threatened plants of India- A state of the Art Report. In 1984, BSI published a book named the Indian plant red data book-I having 125 Data sheets of flowering plants and edited by S.K. Jain & A.R.K. Sastry.
Several other researchers also worked on threatened and endemic plant species and published different volumes of Red Data Books e.g. Vol.I of Red Data Books on Indian Plants edited by M.R. Nayar and A.R.K. Sastry was published by BSI in 1987, which includes 235 vascular plant species of Indian flora. Vol.II of the same editors in 1988 having 192 Data sheets on threatened vascular plants & Vol.III of the same editors in 1990 having 195 threatened taxa of Indian flora.
According to the red data book of IUCN, more than 1000 creatures are threatened with extinction e.g., all species of rhinoceros, Royal Bengal, and Siberian Tigers, Mexican grizzly bear, wolf, mountain gorilla, Arabian oryx and Asiatic lion. In India, nearly 450 plant species are either endangered, threatened or rare. Some animal species have been identified as endangered ones.
They are Hoolock gibbon (the only ape in India), some sp. of macaque, Nilgiri langur, Indian wolf, sloth bear, red panda desert cat, Great Indian one-horned rhinoceros, Asiatic two- horned rhinoceros, musk deer, wild yak, Gangetic dolphin, swans, geese, many hawks, the great Indian bustard, the estuarine crocodile, gharial, Indian python, Indian salamander, a large hermit crab, Indian vultures etc.
The oriental white-backed vulture, once thought to be the commonest bird of prey in the world, has lost 99.9% of its population since 1992, (study by Bombay Natural History Society). Numbers of long-billed and slender-billed vultures have together fallen by almost 97% in the same period.
The no. of oriental white backed vultures is down to 11000 as compared to around 30 million across northern India in the early 1990s. The population of long-billed and slender billed vultures has dropped to around 45000 and 1000 birds respectively. All three species could be down to a few hundred birds or less across the whole country and thus become functionally extinct in less than a decade.
Dr. Oak of Washington found that the above three species of the vultures in India & Pakistan feed on the dead cattle first because of their aggressive nature. Scientists found that an anti-inflammatory drug for cattle especially Diclofenac Sodium increases the quantity of uric acid in the vultures and ultimately causes the kidney failure.
Therefore, the use of veterinary diclofenac has been banned since 2006. But also a version of diclofenac developed for human use is being utilised by farmers to treat livestock. Because it’s an effective drug vets and farmers are just buying it from pharmacies for use.
The removal of vultures from Indian and Pakistan ecosystem causes the dramatic impacts on the environment. The white backed vultures was the primary scavenger. Now Piles of carcases are not being eaten up, increasing the risk of contamination of water bodies.
Other scavengers such as rats and feral (wild) dogs are also moving in. Besides the declining numbers are also a matter of concern for the Parsi communities who leave their dead body out in the open space to be consumed by vultures. One of Indian’s three captive breeding centres enjoyed its first success when two oriental white-backed vulture chicks were born.
Biodiversity hot spots were originally identified by Norman Myers in 1990s to designate an area which faces serious threat from human activities and supports a unique biodiversity with representatives of evolutionary process of speciation & extinction. It is the geographical zone or ecological niche with a large no. of endemic plants. There are 20 hot spots of biodiversity all over the world, a habitat of about 49,550 endemic species of higher plants representing about 20% of the world’s total plant species.
The no. of hot spots in the world has now increased to 34, accounting for just 1.4% of the world’s land and support 60% of species on earth. India has four hot spots viz., North-East, Eastern Himalayas, and Western Ghats & Andaman & Nicobar Island. In addition to these, special hot spots are the mangroves, wetlands & swamps.
To conserve rare and threatened species it is necessary to protect their natural habitats and specific measures are taken to prevent their unplanned exploitation & illegal trade.
The method of conservation of biodiversity is grouped into two heads:
(1) In-situ conservation i.e., the conservation in its natural habitat.
(2) Ex-situ conservation i.e., the conservation outside the natural area.
Such measures which conserve the genetic resources through their maintenance within natural or human made ecosystems in which they occur. Such natural habitats are declared as protected areas.
Yellow Stone Park (Y.S.R) is the first National Park of the world and established in 1872 in America. Hailey National Park is the First national park of India established in 1936. A protected area is such area of land and or sea especially dedicated to the protection and maintenance of biological diversity, and of natural and associated cultural resources and managed through legal or other effective means.
The protected areas are:
a) Wildlife sanctuaries.
b) National parks.
c) Biosphere reserve.
a) Wildlife Sanctuary:
Wildlife sanctuary is an area constituted by competent authority in which killing and capturing of any form of wild life is prohibited except with permission and the boundaries and character of which are sacrosanct. By the year 2000, there were 490 sanctuaries in India.
b) National Park:
National Park is a reserve of land, usually owned by a national government that is protected from most human development and pollution. In India there were 88 National Parks (NP) by the year 2000.
c) Biosphere Reserve:
Biosphere Reserve is an area of terrestrial and coastal ecosystems which are internationally recognised within the framework of UNESCO’s [United Nations Educational, Scientific & Cultural Organisation] Man and Biosphere (MAB) Programme Objectives of Biosphere Reserves-
i) To conserve diversity and integrity of plants, animals & microorganisms.
ii) To promote research on ecological conservation & other environmental aspects.
iii) To provide facilities for education, awareness and training.
iv) To develop database and to make plans to conserve key species.
v) To establish research stations and to implement social welfare activities.
It represents different aquatic habitats of. international importance and is named so after the Ramsar (Iran) convention held in 1971 to protect the ecosystem of wetlands, aquatic species, specially the water birds, and to make wise use of the wetlands for the benefit of people.
This convention came in to existence in 1975 and India became a party to it in 1981. In India a total of 16 Ramsar sites have been identified, covering about 1.1 million hectare, including the Andaman & Nicobar Islands.
Wetlands are such land transitional between terrestrial and aquatic system where the water table is usually near the surface and land is covered by shallow water. These are life support systems for people living around and are effective in flood control, waste water treatment and winter resorts for a variety of birds for shelter and breeding.
According to the Ramsar convention, wetlands are the areas of marsh, peat lands, artificial or natural, brackish or salt marine water with the depth of which at low tide does not exceed six meters e.g., mangroves, corals, estuaries, lakes etc.
National Monuments & Landmarks:
National Monuments & Landmarks – are often smaller areas designated to preserve unique areas of special national interest.
Some ecosystems are considered sacred and preserved since ancient times as sacred forests groves, lakes, ponds, caves, mountains etc. A grove is a small area of land having particular type of trees. Such sacred groves are Bamboo groves of Rajbanshi community of W.B., Orans of West Rajasthan, Sarnas of Chhattisgarh & Chhota Nagpur, Maw- Bukhars of Khasis (Meghalaya), Devrais of Maharashtra, Kovil Kadu of T.N., Kuvus of Kerala etc.
It is a protected area and reserved by the silent valley protected area (Conservation and Ecological Balance) Act, 1979. It is situated in the Kundali hills (Nilgiri) of Western valley of Kerala. It is the only tropical evergreen forest of India which is unaffected by human activities. In 1984 (15th November), the whole silent valley was declared as National Park. The silent valley is considered as the central area of Nilgiri Biosphere Reserve.
It involves maintenance and breeding of endangered plant and animal species under partially or wholly controlled conditions in botanical garden (arboreta/Herbal garden), nurseries, zoos, conservation stands and gene bank, seed (germplasm) bank, pollen bank, semen/ovum bank, tissue culture and DNA banks.
Germplasm Banks/Gene Banks:
Such banks are established for ex-situ conservation of the species and include botanical gardens/arboreta, animal zoos, genetic resource centres, culture collections etc. In plant species, seeds, pollen grains, vegetative propagative parts, tissues etc., are collected and stored in such germplasm banks. IPGRI (International Plant Genetic Resources Institute, Rome) has come up for ex-situ conservation of plant genetic resources.
In our country on Indo-US project on plant genetic resources was taken up in 1988 to establish a National Gene Bank. Seeds of most plant species are stored in cold, dry conditions in seed banks for long periods and then later germinated to form new plants.
China & USA have set up research centres for endangered species. China has recently established IVF (in vitro Fertilization) facility at the embryo engineering laboratory for giant pandas and other endangered species in Chengdu. In our country the third of its kind in the world, a research centre for the conservation of endangered species has been set up near Nehru Zoological Park, Hyderabad.
One of the objectives of this centre is to establish gene banks and improve the reproductive capacity of endangered animals by various assisted reproductive technologies like electro- ejaculation, IUI (Intro-Uterine Insemination), IVF, GIFT (gamete intrafallopian tube transfer), ZIFT (Zygote intra fallopian tube transfer) and ET (embryo transfer).
The United Nations conference on Human Environment, held at Stockholm (Sweden) in 1972 (Stockholm Conference) was the first major step from the U.N. to address the growing problem of environmental degradation and need to conserve and protect the human environment at international level. The late Mrs. Indira Gandhi, the then Prime Minister of India participated in this conference and emphasised that the removal of poverty is an integral part of the goal of an environmental strategy for the world.
Brundtland Commission laid down the concept of sustainable development in 1980. In 1980, IUCN in collaboration with UNEP (United Nations Environment Programme), WWF (World Wildlife Fund) and UNESCO (United Nations Educational, Scientific and Cultural Organisation) developed a strategy on the use of various resources. The strategy aimed at the sustainable utilization of species and the ecosystems which support millions of communities as well as industries.
After the strategy United Nations conference on environment and development was held in Rio de Janerio in 1992. This conference was also known as Earth Summit. The convention on Biodiversity (CBD) was tabled at the conference, and came into force at the end of 1993. India became a party of it in 1994 because India is one of the 12 so called mega bio-diverse countries of the world. World summit on sustainable Development (WSSD) was held in 2002 in South Africa.
After Stockholm Declaration of 1972, Indian Parliament inserted two Articles 48A and 51A in the constitution of India in 1976. Article 48A-rightly directs that the state shall endeavour to protect and improve the environment and safeguard forests and wildlife of the country. Similarly, clause (g) of Article 51A imposes a duty on every citizen of India to protect and improve the natural environment including forests, lakes, river and wild life and to have compassion for living creatures.
But in India, the first codified law which initiated a series of law dates back to 1873 when British rulers enacted Madras Wild Elephant Preservation Act and the All India Elephant Preservation Act, 1879 which were closely followed by the Birds Protection Act 1887. The constitutional provisions of our country are backed by a number of laws, rules and notifications. The Department of Environment was established in 1980 to ensure a healthy environment which later becomes the Ministry of Environment & Forests in 1985.
The Environment (Protection) Act 1986 came into force soon after the Bhopal Gas Tragedy. Biological Diversity Act, 2002 was enacted by our parliament to provide for conservation of biological diversity, sustainable use of its components and equitable sharing of the benefits arising out of the use of biological resources and for matters connected therewith or incidental thereto.
The National Biodiversity Authority (NBDA) has been set up at Chennai in 2003 under the Biological Diversity Act, 2002 to deal with requests for access to genetic resources by foreigners, and 10 manage requests to transfer the result of any related research out of India.
National Environment Policy, 2006 recognises the mangroves and coral reefs as important coastal environmental resources. Mangroves are such plants who survive on high salinity, tidal extremes, strong winds, high temperature and muddy anaerobic soil. Mangroves protect coastal communities from cyclones and coastal storms. India is the home to the best mangroves in the world e.g. Sunderbans.
Coral Reefs are shallow water tropical marine ecosystems, characterised by high biomass production and rich floral and faunal diversity. Four coral reefs i.e. Gulf of Mannar, Andaman & Nicobar Islands, Lakshadweep islands & Gulf of Kutchchh are identified for conservation & management.
A no. of wildlife acts have been made from time to time, by state as well as union government for protection of wildlife viz.:
i) Madras Wild Elephant Preservation Act, 1873.
ii) All-India Elephant Preservation Act, 1879.
iii) The Wild Birds and Animals Protection Act, 1912.
iv) Bengal Rhinoceros Preservation Act, 1932.
v) Indian Board for Wildlife, 1952.
vi) Prevention of Cruelty to Animals Act, 1960.
vii) Wildlife (Protection) Act, 1972.
viii) National Wildlife Action Plan, 1982.
Wildlife (Protection) Act:
Wildlife (Protection) Act, 1972 was passed to provide greater attention to conservation of wildlife. This Act was amended in 1991 to make more comprehensive and provide for setting up of zoo authority of India, oversee management of zoos in the country, protection of rare and endangered spp. and also empowering individuals to file complaints against offenders.
The Wildlife (Protection) Act has been again amended in the year 2002. In this amendment, National Wildlife Board has been constituted as statutory board with PM as the chairman. There is also provision for Community Reserve and Conservation Reserve.
Indian Forest Act:
Indian Forest Act was passed in the year 1865 in which there were provision of cultivation and grazing on forest land and protection of trees and prevention of forest fires. This act was revised in 1878 in which provision of ‘Reserve’ and protected forest made. Rights in reserve forests were extinguished and in protected forests they were defined and recorded at the time of settlement.
This Act was again revised and made a comprehensive Act in the year 1927 which provides for constitution of Reserved Forests, Protected Forests, Village Forests, Demarcation, Transit of Forest Produce, drift wood realization of dues/penalties, cattle trespass etc. Indian forest Act, 1927 (IFA) with various amendments by various states according to the demand of situation, administration, and technical requirement of a particular state, is currently applicable throughout the country.
The Tree Protection Act, 1976 for protection of trees in rural and urban areas of hills was passed to regulate felling of trees on private land in UP IFA, 1927 is the principal legislation for management of forests in Uttarakhand also. This Act has been amended to control illicit activities in the forest by empowering forest office to confiscate STP (Store, tools, plants) used for committing offence and enhancing the scale of fire/imprisonment. The forest (conservation) Act was passed in 1980 and amended in 1988.