Chapter 15 Biodiversity Conservation

NIOS Class 12 Environmental Science Chapter 15

INTEXT QUESTIONS 15.1

1. What do you understand by biological diversity?

Ans: The total of all the varieties of living organisms on earth constitutes biological diversity.

2. List the various levels of biodiversity.

Ans: Biological diversity is usually considered at three different levels: a) genetic diversity, i.e. at the genetic level, b) species diversity, i.e. at the level of species, and c) ecosystem diversity, i.e. at the level of ecosystem.

3. Name the two hot spots in India.

Ans: Western Ghats and Eastern Himalayas

4. Name the most abundant (i) group of plants and (ii) group of animals recorded in India.

Ans: (i)Angiosperms (ii) Arthropods

INTEXT QUESTIONS 15.2

1. Name the three important categories under which the uses of biodiversity can be described.

Ans: The various benefits of biological diversity can be grouped under three categories: a) ecosystem services, b) biological resources, and c) social benefits.

2. Mention two examples of ecosystem services.

Ans: Protection of water resources, protection of soil, climatic control, nutrient storage and cycling, pollution reduction, climate stability and maintenance of ecological processes.

3. List any two ways by which biodiversity contributes towards a cleaner environment.

Ans: Reduce pollutants, maintain the gaseous composition of air, and degradation of wastes.

INTEXT QUESTIONS 15.3

1. Which region in India has the richest wild sheep and goat community in the world?

Ans: The trans-Himalayan region, with its sparse vegetation, has the richest wild sheep and goats community in the world.

2. List any three factors by virtue of which India has a rich and unique biodiversity.

Ans:

Its tropical location
Varied physical features and climatic situations
Meeting of three major biogeographical realms

3. Name the richest regions of biodiversity.

Ans: North-east India is one of the richest regions of biodiversity in the country. It is especially rich in orchids, bamboos, ferns, citrus, banana, mango and jute.

4. What are exotic species? What effect do they have on the local species?

Ans: New species entering a geographical region or exotic species may cause the disappearance of native species through changed biotic interactions.

5. List the three zones of a biosphere reserve, and which one of them allows settlements, etc.

Ans: A Biosphere Reserve consists of core, buffer and transition zones. The transition zone is where settlements are allowed.

6. List the three objectives of the Convention of Biological Diversity signed during the Earth Summit-1993.

Ans: The Convention has three key objectives:

1. Conservation of biological diversity,
2 Sustainable use of biodiversity and
3. Fair and equitable sharing of benefits arising out of the utilisation of genetic resources.

7. Expand IUCN.

Ans: International Union for Conservation of Nature and Natural Resources

8. How many animals and how many plants in India are listed as critically endangered in the Red List?

Ans: 18,44

INTEXT QUESTIONS 15.4

1. What are the main conservation strategies?

Ans: There are two conservation strategies.

In-situ (on-site) conservation includes the protection of plants and animals within their natural habitats or in protected areas. Protected areas are land or sea dedicated to protecting and maintaining biodiversity.
Ex-situ (off-site) conservation of plants and animals outside their natural habitats. These include botanical gardens, zoo, gene banks, seed bank, tissue culture and cryopreservation.

2. Name two important tiger reserves.

Ans: The Jim Corbett Tiger Reserve, Uttaranchal and the Bandipur Tiger Reserve, Tamil Nadu.

3. Expand WCS.

Ans: Wildlife Conservation Society

4. What are the main functions of a biosphere reserve?

Ans: The main functions of the biosphere reserves are:

Conservation: Long-term conservation of representatives, landscapes and different types of ecosystems, along with all their species and genetic resources.
Development: Encourages traditional resource use and promotes economic development, which is culturally, socially and ecologically sustainable.
Scientific research, monitoring and education- Support conservation research, monitoring, education and information exchange related to local, national and global environmental and conservation issues.

5. Expand the following:

i. NBPGR ii. NBG, iii. CITES, iv. IUCN, v. CBD, vi. NBA.

Ans:

i. National Bureau of Plant Genetic Resources, New Delhi
ii. National Botanical Garden
iii. Convention on International Trade in Endangered Species of Wild Fauna and Flora
iv. The International Union for the Conservation of Nature and Natural Resources.
v. Convention on Biological Diversity
vi. National Biodiversity Authority

TERMINAL EXERCISE

1. What is biodiversity? Why has it become important in recent years?

Ans: The total of all the varieties of living organisms on earth constitutes biological diversity. Humans depend on nature for their sustenance, health, well-being and cultural growth on nature. Biotic resources provide food, fruit, seed, fodder, medicines and a host of other goods and services. The enormous diversity of life is of immense value, imparting resilience to ecosystems and natural processes. Biodiversity also has enormous social and cultural importance.

2. List different levels of biodiversity and explain what is meant by genetic diversity.

Ans: Biological diversity is usually considered at three different levels

a) genetic diversity, i.e. at the genetic level
b) species diversity, i.e. at the level of species
c) ecosystem diversity, i.e. at the level of the ecosystem.

Genetic Diversity refers to the variety of genes contained within species of plants, animals and microorganisms. New genetic variation in individuals occurs by gene and chromosomal mutation, and in organisms with sexual reproduction, may be spread across the population by recombination.

The amount of genetic variation (gene pool) present in an inter-breeding population is shaped or determined by the process of natural selection. Selection leads to certain genetic attributes being preferred and results in changes in the frequency of genes within this pool. This forms the basis of adaptation among the living organisms.

3. What are the various in-situ methods of conservation?

Ans: In-situ (on-site) conservation includes the protection of plants and animals within their natural habitats or in protected areas. Protected areas are land or sea dedicated to protecting and maintaining biodiversity.

i) Protection of habitat: The main strategy for conservation of species is the protection of habitats in representative ecosystems. It is implemented in the forms of National Parks, Wildlife Sanctuaries, Biosphere Reserves, Tiger Reserves, Elephant Reserves, wetlands, mangrove areas and coral reef areas for intensive conservation and management.
ii) Species-oriented projects: Certain species have been identified as needing a concerted and specifically directed protection effort. Project Tiger, Project Elephant and Project Crocodile are examples of focusing on single species through conserving their habitats.
(iii) Sacred forests and sacred lakes: A traditional strategy for the protection of biodiversity has been in practice in India and some other Asian countries in the form of sacred forests. These are small forest patches protected by tribal communities due to religious sanctity. These have been free from all disturbances.

4. Write short notes on :

a) Cryopreservation

b) Protected areas

c) Biosphere Reserves,

d) IUCN Red List

e) Gene banks

f) Hot spots of biodiversity

g) Biodiversity Act,2002.

Ans:

a) Cryopreservation

Cryopreservation means freeze preservation, which is useful in conserving vegetatively propagated crops. Cryopreservation is the storage of material at ultra-low temperature of liquid nitrogen (-1960C) and essentially involves suspension of all metabolic processes and activities. Cryopreservation has been successfully applied to meristems, zygotic and somatic embryos, pollen, protoplast cells and suspension cultures of several plant species.

b) Protected areas

Protected areas are land or sea dedicated to protecting and maintaining biodiversity.

i) Protection of habitat: The main strategy for conservation of species is the protection of habitats in representative ecosystems. It is implemented in the forms of National Parks, Wildlife Sanctuaries, Biosphere Reserves, Tiger Reserves, Elephant Reserves, wetlands, mangrove areas and coral reef areas for intensive conservation and management.
ii) Species-oriented projects: Certain species have been identified as needing a concerted and specifically directed protection effort. Project Tiger, Project Elephant and Project Crocodile are examples of focusing on single species through conserving their habitats.
(iii) Sacred forests and sacred lakes: A traditional strategy for the protection of biodiversity has been in practice in India and some other Asian countries in the form of sacred forests. These are small forest patches protected by tribal communities due to religious sanctity. These have been free from all disturbances.

c) Biosphere Reserves

These are representative parts of natural and cultural landscapes extending over large areas of terrestrial or coastal/marine ecosystems, which are internationally recognised within UNESCO’s Man and the Biosphere Programme. Thirteen biodiversity-rich- rich representative ecosystems, largely within the forest land ( total area – 53,000 sq. km. ), have been designated as Biosphere Reserves in India. A Biosphere Reserve consists of core, buffer and transition zones.

(a) The core zone is fully protected and a natural area of the Biosphere Reserve, least disturbed by human activities.
(b) The buffer zone surrounds the core zone and is managed to accommodate a greater variety of resource use strategies and research and educational activities.
(c) Transition zone, the outermost part of the Biosphere Reserve, is an area of active cooperation between the reserve management and the local people, wherein activities like settlements, cropping, forestry, recreation and other economic that are in harmony with the conservation goals.

d) IUCN Red List

The IUCN Red List is an authentic source of information on the status of threatened species. The 2000 Red List is the latest available. It uses a set of criteria, relevant to all species and all regions of the world, to evaluate the extinction risk of species. The 2000 Red List contains an assessment of more than 18,000 species; 11,000 of which are threatened (5,485 animals and 5611 plants). Out of these, 1,939 are listed as critically endangered (925 animals and 1,014 plants). According to the Red List, in India, 44 plant species are critically endangered, 113 endangered and 87 vulnerable. Amongst animals, 18 are critically endangered, 54 are endangered, and 143 are Vulnerable.

e) Gene banks

Ex-situ collection and preservation of genetic resources is done through gene banks and seed banks. The National Bureau of Plant Genetic Resources (NBPGR), New Delhi, preserves seeds of wild relatives of crop plants as well as cultivated varieties; the National Bureau of Animal Genetic Resources at Karnal,

Haryana maintains the genetic material for domesticated animals, and the National Bureau of Fish Genetic Resources, Lucknow, for fish.

f) Hot spots of biodiversity

Hot spots are those regions of the world that are very rich in biodiversity. It is also called mega diversity. They are the richest and most threatened reservoirs of biodiversity on the earth. The criteria for determining a hot spot are:

i) The area should support >1500 endemic species,

ii) It must have lost over 70 % of its original habitat

Among the 25 hot spots of the world, 2 are found in India, namely the Western Ghats and the Eastern Himalayas. These two areas of the country are exceptionally rich in flowering plants, reptiles, amphibians, butterflies and some species of mammals.

g) Biodiversity Act, 2002

This Act provides for the setting up of a National Biodiversity Authority (NBA), State Biodiversity Boards (SBB) and Biodiversity Management Committees (BMC) in local bodies. All foreign national organisations require prior approval of the NBA for obtaining biological resources and/or associated knowledge for any use. Similarly, Indian nationals or organisations will be required to give prior intimation to the concerned SBB about any biological resources being imported for commercial use. The SBB may prohibit the import if found to violate the objectives of conservation, sustainable use and benefit sharing.

5. Describe various causes of depletion of biodiversity.

Ans: The threat to survival or loss may be caused in the following three ways:

Direct ways: Deforestation, hunting, poaching, and commercial exploitation.
Indirect ways: Loss or modification of the natural habitats, introduction of exotic species, pollution, etc.
Natural causes – Climate change.

Among these causes, habitat destruction and over-exploitation are the main.

i) Habitat (natural home) destruction may result from clearing and burning forests, draining and filling of wetlands, converting natural areas for agricultural or industrial uses, human settlements, mines, building of roads and other developmental projects. This way, the natural habitats of organisms are changed or destroyed. These changes either kill or force out many species from the area, disrupting interactions among the species.
ii) Introduction of exotic species: When seeds from other areas happen to migrate to new places, they breed extra fast due to the absence of any enemies and often wipe out the native species already present there. Exotic species (new species entering a geographical region) may wipe out the native ones.
iii) Pollution: Air pollution, acid rain destroys forests. Water pollution kills fish and other aquatic plants and animals. Toxic and hazardous substances drained into waterways kill aquatic life. Oil spills kill coastal birds, plants and other marine animals. Plastic trash entangles wildlife. It is easy to see how pollution is a big threat to biodiversity.
iv) Population growth and poverty: Over six billion people who live on the earth use natural resources for food, water, medicine, clothes, shelter and fuel. The needs of the poor and often greed of the rich generate continuous pressure, resulting in over-exploitation and loss of biodiversity.

6. How is biodiversity distributed along major environmental gradients?

Ans: Biological diversity is usually considered at three different levels: a) genetic diversity, i.e. at the genetic level, b) species diversity, i.e. at the level of species, c) ecosystem diversity, i.e. at the level of ecosystem.

Genetic Diversity refers to the variety of genes contained within species of plants, animamicroorganismsmss. New genetic variation in individuals occurs by gene and chromosomal mutation, and in organisms with sexual reproduction, may be spread across the population by recombination. The amount of genetic variation (gene pool) present in an inter-breeding population is shaped or determined by the process of natural selection. Selection leads to certain genetic attributes being preferred and results in changes in the frequency of genes within this pool. This forms the basis of adaptation among living organisms.
Species diversity refers to the variety of species within a geographical area. It can be measured in terms of:
- (a) Species richness – refers to the number of various species in a defined area.
- (b) Species abundance – refers to the relative numbers among species. For example, the number of species of plants, animals and microorganisms may be more in an area than that recorded in another area.
- (c) Taxonomic or phylogenetic diversity – refers to the genetic relationships between different groups of species.
Ecosystem diversity refers to the presence of different types of ecosystems. For instance, the tropical south India with rich species diversity will have an altogether different structure compared to the desert ecosystem, which has far less number of plant and animal species. Likewise, the marine ecosystem, although it has many types of fish, differs from the freshwater ecosystem of rivers and lakes in terms of its characteristics. So such variations at the ecosystem level are termed ecosystem diversity.
Hot spots are those regions of the world that are very rich in biodiversity. It is also called mega diversity. They are the richest and the most threatened reservoirs of biodiversity on the earth. The criteria for determining a hot spot are:
- i) The area should support >1500 endemic species,
- ii) It must have lost over 70 % of its original habitat

7. Write a brief note on biodiversity conservation efforts in India.

Ans: Conservation is the planned management of natural resources to retain the balance in nature and maintain the diversity. It also includes the wise use of natural resources in such a way that the needs of the present generation are met, and at the same time, leaving enough for future generations. Conservation of biodiversity is important to:-

Prevent the loss of genetic diversity of a species,
Save a species from becoming extinct, and
Protect ecosystems from damage and degradation.

Conservation efforts can be grouped into the following two categories:

In-situ (on-site) conservation includes the protection of plants and animals within their natural habitats or in protected areas. Protected areas are land or sea dedicated to protecting and maintaining biodiversity.
Ex-situ (off-site) conservation of plants and animals outside their natural habitats. These include botanical gardens, zoo, gene banks, seed bank, tissue culture and cryopreservation.

8. Match the words in Column I with those in Column II

Column I	Column II
i) 13000 genes	(a) Lantana camara
ii) Exotic species	(b) Drosophila melanogaster
iii) Transition zone	(c) Red List
iv) Endangered	(d) Biosphere Reserve

Ans:

Column I	Column II
i) 13000 genes	(b) *Drosophila melanogaster*
ii) Exotic species	(a) *Lantana camara*
iii) Transition zone	(d) Biosphere Reserve
iv) Endangered	(c) Red List

9. What is the result of the Earth Summit held at Rio de Janeiro in 1992?

Ans: The Convention has three key objectives:

1. Conservation of biological diversity,
2 Sustainable use of biodiversity and
3. Fair and equitable sharing of benefits arising out of the utilisation of genetic resources.

10. What is an approximate percentage of endemic vascular plants in India?

Ans: About 33% of the flowering plants recorded in India are endemic.