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BIODIVERSITY and CONSERVATION BIOLOGY
The term biodiversity was coined by Walter G Rosen in 1985. It has been defined variously
such as ‘the richness of variety and variability of species of all living organisms in a given region
(habitat)’. According to IUCN, biodiversity is the totality of genes, species and ecosystems in a
region. More commonly, the term biodiversity is used to denote the variety of species of all living
plants, animals and microbes living in their natural habitats.
Biodiversity can be sub divided into three levels as follows:
1. Genetic diversity: It refers to the genetic variations (genes) within a species. Genetic variation
helps in adaptation and act as raw material for evolution.
2. Species diversity: Refers to the variety of species within a region as indicated by species richness.
3. Community or Ecosystem diversity: On a wider scale, biodiversity includes variations in biological
communities in which the species live, the ecosystem in which the communities exists and the
interactions among these levels.
Significance of Biodiversity
Our food and energy security strongly depend on biodiversity and so does our vulnerability
to natural hazards such as fires and flooding. Biodiversity loss has negative effects on our health,
material wealth and it largely limits our freedom of choice. As all cultures gain inspiration from or
attach spiritual and religious values to ecosystems or their components – e.g. landscapes, trees, hills,
rivers or particular species - biodiversity loss also strongly influences our social relations. Some
importances of biodiversity are listed below.
Source of food and raw materials - Biodiversity is essential to global food security and nutrition.
Source of breeding material for improved varieties - Increased diversity of genes within species e.g.
as represented by livestock breeds or strains of plants, reduces risk from diseases and increases
potential to adapt to changing climates.
New medicines, pharmaceuticals, pesticides etc. - More than 70,000 plant species are used in
traditional and modern medicine.
Aesthetic and cultural significance – Wildlife, ecotourism, sacred groves etc.
Ecosystem services – Preserve climate, soil, ground water, nutrient cycling. Helps in pollination,
purification of air, water etc. The value of global ecosystem services is estimated at $16-$64 trillion.
Loss of biodiversity
Despite knowing about biodiversity’s importance for a long time, human activity has been
causing rapid loss in biodiversity. Current rates of biodiversity loss have been estimated to be as high
as 1,000 to 10,000 times faster than rates indicated in fossil records. The main reasons of
biodiversity loss are deforestation, desertification, overexploitation, invasive species, pollution, and
climate change. Overuse of natural resources can lead to ecosystem degradation, and ultimately to
extinction of flora and fauna. The most serious aspect of the loss of biodiversity is the extinction of
species. Communities can be degraded and reduced in areas, but as long as the original species
survive, the communities still have the potential to recover. A species is considered extinct when no
member of the species alive anywhere in the world.
Dr. Siju Thomas. T | Asst. Professor, Dept. of Botany, Mar Athanasius College, Kothamangalam
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When the environment is damaged by human activity, the population size of many species will be
reduced, and some species will go extinct. It was noted that not all species have equal probability of
going extinct, but some categories of species are more vulnerable to extinction. Following are such
species categories which are more susceptible to extinction.
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Organisms with large body mass – Bengal tiger, Elephants, Lions
Species with small population size and low reproductive rates – Blue whale, Giant panda
Organisms feeding at higher trophic levels – Bald eagle, Vultures, Bengal tiger
Organisms with fixed migratory paths and habitats – Birds, Butterflies
Organisms with localized narrow range of distribution – Island species
Causes of extinction / biodiversity loss
Human activity is the major threat to biodiversity and following are the chief causes for the loss of
biodiversity leading to the extinction of species.
Habitat destruction (habitat loss): The primary cause of biodiversity loss is habitat destruction
resulting from the expansion of human population and human activities. The natural habitats of
many organisms have been destroyed by deforestation, industrialization, dams, mining, grazing,
expansion of agricultural fields, pollution and so on. Rain forests, wetlands, mangroves and
grasslands are the most threatened habitats from human activities.
Habitat fragmentation: Habitat fragmentation is the process where a large, continuous area of
habitat is reduced in area and divided into two or more fragments. Habitats once occupied by wide
areas are now divided up into pieces by roads, towns, canals, power lines, crop fields etc. These
fragments are isolated from one another by degraded of modified landscape. Habitat fragmentation
limits the potential of species for dispersal and colonization. It also obstructs migration and reduces
the foraging ability of animals. Habitat fragmentation causes microclimate changes in light,
temperature, wind etc.
Pollution and habitat degradation: Loss quality of natural habitat is often associated with various
types of pollutions. The most common causes include pesticides, industrial chemicals and effluents,
emissions from factories and automobiles. These pollutants degrade soil, air and water quality
making the habitat unsuitable for the survival of native species.
Over exploitation: Increasing human population has escalated the use of natural resources. In most
part of the world today, the resources are exploited as rapidly as possible to meet human needs.
Cutting of trees, poaching of animals and over grazing have contributed to the loss of biodiversity.
Diseases: Rapid spreading of diseases and pests may sometimes lead to the extinction of plant and
animal species. The extent of diseases increases when the animals are confined to a nature reserve
than being able to disperse over a large area.
Introduction of exotic species (alien species): Sometimes along with useful introductions,
propagules of unwanted organisms (weeds, microorganisms, insects etc.) also get introduced into a
new area. Some of these exotic species spread rapidly and affect the growth and survival of local
native organisms. Eg. Eichornia, Lantana etc. Since they are non native, they lack natural predators
or competitors and spread very rapidly. Such successful exotic species may inhibit the growth of
native species to the point of extinction or may alter the habitat that many natives are no longer
able to survive.
Dr. Siju Thomas. T | Asst. Professor, Dept. of Botany, Mar Athanasius College, Kothamangalam
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Some exotic species are useful. They are used as garden plants, ornamental plants, and some are
used in breeding experiments. Some exotic species are even used to generate biofuels.
Modern agricultural practices: Biodiversity loss is severe in modern agro-ecosystems. Many of our
wild crop varieties have been replaced by a few hybrid or improved species during the green
revolution. It resulted in the loss of genetic resources of our crop plants, especially wheat and rice.
Along with these plants, microbial flora has also been lost due to the over use of agro-chemicals
(fertilizers and pesticides).
Conservation of Biodiversity
Conserving biological diversity involves restoring, protecting, conserving or enhancing the variety of
life in an area so that the abundance and distribution of species and communities provide for
continued existence and normal ecological functioning, including adaptation and extinction. It is
reported that during the next 20to30 years, the world would lose more than a million species of
plants and animals-primarily because of environmental changes brought about by human beings.
This demands an urgent attention for the conservation of biosphere. Two strategies have been
followed in biodiversity conservation: in-situ and ex-situ conservation methods.
In-situ conservation
This type of conservation includes conservation of plant and animals in their native ecosystems. Insitu conservation includes a system of protected areas of different categories, e.g., National Park,
Sanctuaries, Biosphere Reserves, Cultural Landscapes, and National Monument, World heritage
sites, sacred groves etc. Natural habitats are declared as protected areas for the purpose of
conservation. According to the World Conservation Union, protected area is defined as "An area of
land and/or sea specially dedicated to the protection and maintenance of biological diversity and of
natural and associated cultural resources and managed through legal or other effective mean." Eg.
Nilgiri biosphere reserve, Eravikulam National park, Periyar tiger reserve etc.
Ex-situ conservation
Ex-situ conservation means conservation of species, particularly of endangered species away from
their natural habitat. It is done through establishment of botanical gardens, zoos, seed (germplasm)
banks, application of biotechnology (tissue culture, cryopreservation) etc.
Conservation strategies and efforts in India and Kerala
Various programmes have been initiated at both national and state levels for conserving biological
diversity. These programmes are aimed at conserving biological diversity and also to create
awareness among people about the importance of biodiversity.
Laws: The Government of India and State Governments have passed many laws for protecting
biodiversity and to control pollution. Some of them are; The environment (protection) act 1986,
Forest (conservation) act 1980, Wildlife (protection) act 1972, The biodiversity act 2002 etc.
Protected areas network: A comprehensive network of protected areas have been initiated by the
Government for the in-situ conservation of biodiversity. The different categories of protected areas
include National parks, sanctuaries, biosphere reserves, national monuments etc. There are about
17 biosphere reserves (Nilgiri biosphere reserve, Agasthyamalai biosphere reserve etc.), 88 national
parks (Eravikulam, Silent valley etc) and more than 200 wild life sanctuaries (Chinnar, Idukki,
Dr. Siju Thomas. T | Asst. Professor, Dept. of Botany, Mar Athanasius College, Kothamangalam
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Wayanad, Periyar etc.) in India at present. These protected areas house large number of endangered
and endemic plants and animals including tigers, Asiatic lions, elephants, one-horned rhinos, lion
tailed macaque, Nilgiri tahrs etc. Biosphere programme was launched under the Man and Biosphere
(MAB) programme of UNESCO. The purpose of formation of biosphere reserve is to conserve in-situ
all forms of life along with its support system in its totality.
Special projects and programmes: In order to protect specific organisms and to create awareness
the government has started some special projects. Some examples are – Project tiger: Initiate during
1973 for protecting Royal Bengal Tiger. It has a network of tiger reserves across India. Gir lion
project: Protection of lions in the Gir forests, Gujarat. Project elephant: Launched in 1992, for the
conservation of elephant population.
The Government has also initiated Nature camps, ecotourism packages etc. to generate awareness
among public about the importance of wildlife and its conservation.
Government organizations: There are various Government bodies which coordinate the
conservation approaches. The Forests and Wildlife Department, Ministry of Environment and Forests
(MoEF), Indian Board of Wildlife, Central and State Biodiversity Boards are few examples. These
organizations organize afforestation programmes, awareness programmes, nature camps etc. to
sensitize people about the importance of biodiversity.
Research organizations like Tropical Botanical Garden and Research Institute (TBGRI), Botanical
Survey of India, Zoological Survey of India etc. are also involved in biodiversity conservation
programmes.
Non Government Organizations (NGOs): There are also various NGOs working on wildlife
conservation in India such as, Rhino Foundation for Nature (Assam), Friends of Forests
(Maharashtra), Kerala Sastra Sahitya Parishad (Kerala), Centre for Science and Environment, Bombay
Natural History Society, Narmada Bachao Andolan etc. These NGOs work towards generating
awareness and conserving biological diversity.
Role of NGOs in biological conservation
Non Government Organizations play a significant role in conserving biodiversity. They work at the
grass root level with local people and generate awareness towards protecting biodiversity. India has
a number of NGOs that work in the field of environmental conservation. They educate and conduct
programmes in the area of pollution management, forest and wildlife protection, eco-restoration,
non-conventional energy resources and so on. They also conduct environmental surveys and
environmental impact assessments.
NGOs also organize massive campaigns and agitations against unplanned developmental
programmes of the government such as dams, hydroelectric projects etc. that may lead into
environment degradation. One such example was the campaign lead by Kerala Sastra Sahitya
Parishad for saving Silent valley forests from a hydroelectric project. Similarly, Narmada Bachao
Andolan is also fighting against the Sardar Sarovar Dam. Many NGOs that work at regional level
disseminate and popularize information regarding soil and water conservation, alternate energy
resources and sustainable and equitable development.
Quite often, these NGOs work more effectively than Government organizations and act as a
corrective mechanism in environment related developmental issues.
Dr. Siju Thomas. T | Asst. Professor, Dept. of Botany, Mar Athanasius College, Kothamangalam
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Endemism
The phenomenon of restricted distribution of a species associated with some ecological factors is
called endemism. A taxon whose distribution is confined to a small area and associated with
particular habitat conditions is called endemics. The endemic species are far more vulnerable to
extinction than other species because once they are lost, the loss of biodiversity is forever. Some
species are spread over a wide area in different ecological conditions, such species are known as
cosmopolitan.
Broadly, there are two types of endemics;
1. Palaeo endemics: These are survivors of once widely distributed ancestral forms that have
become restricted in distribution due to changes in climatic conditions. Eg. Ginkgo biloba (restricted
in China and Japan), Sequoia sempervirens (restricted to coastal areas of California, USA).
These types have many fossil relatives and are also called living fossils. They are also known as relics
or epibionts. They are adapted to grow in a particular environment but fail to establish in new areas
with change in climate.
2. Neo endemics: They are relatively new species, which have had not enough time for occupying a
large area through migration during the course of evolution.
Factors/Reasons for endemism
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Endemic species are poor in adaptation to different types of environmental conditions
They require specific microclimatic conditions
They remain restricted to particular place due to geographical barriers – sea, mountain
ranges etc.
They produce less efficient propagules – seeds, fruits, spores – that fail to disseminate to far
off places
Hotspots of biodiversity and endemism
A biodiversity hotspot is a biogeographic region with a significant reservoir of biodiversity that is
under threat from humans. The concept of biodiversity hotspots was developed by Norman Myers in
1990s. A hotspot should also have a large number of endemic species. Over 50 percent of the
world’s plant species and 42 percent of all terrestrial vertebrate species are endemic to the 34
biodiversity hotspots of the world.
India with its unique geographical position has large variations in climate, soil, flora and fauna
making it rich in biological diversity. India is one of the 12 mega biodiversity centres of the world.
India ranks tenth in the world both in respect of richness of flowering plants (17,000spp.) and
mammals (372 spp.). India has many endemic plant and vertebrate species. There are about 5725
endemic taxa of angiosperms (33% of Indian flora). Endemism among mammals and birds is
relatively low. Only 44 species of mammals and 55 species of birds are endemic to India. In contrast,
endemism in the Indian reptilian and amphibian fauna is high. There are around 187 endemic
reptiles and 110 endemic amphibian species. India has three regions qualify the criteria for hotspots
with high degree of endemism and biodiversity – the western ghats, eastern Himalayas and north
east India.
Dr. Siju Thomas. T | Asst. Professor, Dept. of Botany, Mar Athanasius College, Kothamangalam
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Western Ghats – hottest spot of biodiversity
The Western Ghats are a chain of highlands running along the western edge of the Indian
subcontinent, from Bombay south to the southern tip of the peninsula, through the states of
Maharashtra, Karnataka, Kerala and Tamil Nadu. The area is one of the world’s ten "Hottest
biodiversity hotspots" and has over 4000 species of flowering plants, 139 mammal species, 508 bird
species and 179 amphibian species, many undiscovered species lives in the Western Ghats. At least
325 globally threatened species occur in the Western Ghats. The Western Ghats presents a whole
range of gradients, both altitudinal as well as latitudinal in climatic factors, such as total annual
rainfall, maximum temperatures. This tremendous environmental heterogeneity found across the
Ghats, of topography, soils, rainfall, number of dry months per year and temperature, makes for an
extremely environmentally heterogeneous biogeographic area, with a tremendous amount of
diversity, both plant and animal. The tropical climate with heavy precipitation and suitable edaphic
factors is ideal for luxuriant plant growth. Different types of forests are seen in the area such as
evergreen forests, dry deciduous forests, rain forests and shola forests.
The plant species known to be from the Western Ghats is about 4500 species out of which 35
percent are endemic. Levels of endemism in this area are high – nearly 2000 species of higher plants,
84 species of fishes, 87 species of amphibians, 89 species of reptiles, 15 species of birds and 12
species of mammals are endemic to the Western Ghats.
Four endemic animal species of conservation significance occur in the Western Ghats. They are the
Lion-tailed macaque Macaca silenus, Nilgiri leaf monkey Trachypithecus johni (locally better known
as Nilgiri langur Presbytis johnii), Brown palm civet Paradoxurus jerdoni and Nilgiri tahr Hemitragus
hylocrius.
There are 32 endemic plant genera in Western Ghats. They include Anaphyllum (2 spp.), Ascopholis,
Baeolepis, Blepharistemma, Carvia, Polyzygus, Silentvalleya, Taeniandra, Utleria, Willisia and
Xenacanthus (3 spp.). Out of the 115 monotypic endemic genera reported from India, 29 are
reported from these regions. In addition to these, the presence of 27 common endemic genera in
Peninsular India and Sri Lanka is interesting from the phytogeographical angle. A large concentration
of endemic species is found in the tropical moist deciduous and tropical semi evergreen patches of
the Western Ghats. There are 5 families with a high percentage of endemism viz., Balsaminaceae
with 80 species, Euphorbiaceae (34), Rubiaceae (34), Myrtaceae (30) Lauraceae (22) are occurring in
the Western Ghats. The gymnosperm flora is represented by Cycas circinalis (Cycadales), Podocarpus
wallichianus (Coniferales) and Gnetum ula.
As the zone has already lost a large part of its original forest cover it must rank as a region of great
conservation concern. The small remaining extent of natural forest, coupled with exceptional
biological richness and ever increasing levels of threat are factors which necessitate major
conservation inputs. For the protection of biodiversity, there are currently seven national parks in
the Western Ghats with a total area of 2,073 sq. km (equivalent to 1.3% of the region) and 39
wildlife sanctuaries covering an area of about 13,862 sq. km (8.1%). The southern part of the
western ghats is declared as Nilgiri biosphere reserve.
Dr. Siju Thomas. T | Asst. Professor, Dept. of Botany, Mar Athanasius College, Kothamangalam
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IUCN Red list and Red Data Book
The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List), founded
in 1963, is the world's most comprehensive inventory of the global conservation status of biological
species. The International Union for Conservation of Nature (IUCN) is the world's main authority on
the conservation status of species. IUCN is also known as World Conservation Union. A series of
Regional Red Lists and Red Data Books are produced by countries or organizations, which assess the
risk of extinction to species within a region.
IUCN species survival commission under the IUCN species programme assess the conservation status
of species of plants and animals on a global scale and publish the Red list and Red Data Book. The
Red List is set upon precise criteria to evaluate the extinction risk of thousands of species and
subspecies. These criteria are relevant to all species and all regions of the world. The IUCN aims to
have the status of every species re-evaluated every five years. The Red List provides current status of
globally threatened biodiversity. The aim is to convey the urgency of conservation issues to the
public and policy makers, as well as help the international community to try to reduce species
extinction.
Species are classified by the IUCN Red List into nine groups, set through criteria such as rate of
decline, population size, area of geographic distribution, and degree of population and distribution
fragmentation.
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Extinct (EX) – No known individuals remaining.
Extinct in the Wild (EW) – Known only to survive in captivity, or as a naturalized population
outside its historic range.
Critically Endangered (CR) – Extremely high risk of extinction in the wild.
Endangered (EN) – High risk of extinction in the wild.
Vulnerable (VU) – High risk of endangerment in the wild.
Near Threatened (NT) – Likely to become endangered in the near future.
Least Concern (LC) – Lowest risk. Does not qualify for a more at risk category. Widespread
and abundant taxa are included in this category.
Data Deficient (DD) – Not enough data to make an assessment of its risk of extinction.
Not Evaluated (NE) – Has not yet been evaluated against the criteria.
Three categories: Critically Endangered, Endangered, and Vulnerable are together designated with
the term "threatened".
Threatened flora and fauna in India
According to Red list, in India among plants 44 species are critically endangered, 113 sps are
endangered and 87 sps are vulnerable. Some examples of threatened animal and plant species are
given below.
Animals: Indian one horned rhinos, Royal Bengal Tiger, Lion tailed Macaque, Nilgiri tahr, Asiatic
lions, Horn bills etc.
Plants: Santalum album, Gnetum ula, Piper barberi, Cycas beddomei, Dioscoria wightii, various
species of orchids (Dendrobium, Cymbidium etc.) etc.
Dr. Siju Thomas. T | Asst. Professor, Dept. of Botany, Mar Athanasius College, Kothamangalam
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