Biodiversity Unit 4 PDF

Unit4 11-11-2024 1  What is biodiversity? 'Biological diversity’ or biodiversity is that part of nature which includes the differences in genes among the individuals of a species, the variety and richness of all the plant and animal species at different scales in space, locally, in...

Unit4 11-11-2024 1  What is biodiversity? 'Biological diversity’ or biodiversity is that part of nature which includes the differences in genes among the individuals of a species, the variety and richness of all the plant and animal species at different scales in space, locally, in a region, in the country and the world, and various types of ecosystems, both terrestrial and aquatic, within a defined area. Biological diversity deals with the degree of nature’s variety in the biosphere. This variety can be observed at three levels; ❖the genetic variability within a species, ❖the variety of species within a community, ❖and the organization of species in an area into distinctive plant and animal communities constitutes ecosystem diversity. 11-11-2024 2 Genetic diversity Each member of any animal or plant species differs widely from other individuals in its genetic makeup because of the large number of combinations possible in the genes that give every individual specific characteristic. This genetic variability is essential for a healthy breeding population of a species. If the number of breeding individuals is reduced, the dissimilarity of genetic makeup is reduced and in-breeding occurs. Eventually, this can lead to the extinction of the species. The diversity in wild species forms the ‘gene pool’ from which our crops and domestic animals have been developed over thousands of years. Ex: Roses with different colors 11-11-2024 3  Species diversity The number of species of plants and animals that are present in a region constitutes its species diversity. This diversity is seen both in natural ecosystems and in agricultural ecosystems. Natural undisturbed tropical forests have a much greater species richness than plantations developed by the Forest Department for timber production. At present, conservation scientists have been able to identify and categorize about 1.8 million species on Earth. However, many new species are being identified, especially in flowering plants and insects. Areas that are rich in species diversity are called ‘hotspots’ of diversity. India is among the world’s 15 nations that are exceptionally rich in species diversity. 11-11-2024 4 11-11-2024 5 Ecosystem diversity There is a large variety of different ecosystems on earth, which have their own complement of distinctive interlinked species based on the differences in the habitat. Ecosystem diversity can be described for a specific geographical region or a political entity such as a country or a State. If natural ecosystems are overused or misused, their productivity eventually decreases, and they are then said to be degraded. 11-11-2024 6 11-11-2024 7 BIOGEOGRAPHIC CLASSIFICATION OF INDIA Our country can be conveniently divided into ten major regions, based on the geography, climate, and pattern of vegetation seen and the communities of mammals, birds, reptiles, amphibians, insects, and other invertebrates that live in them. Each of these regions contains a variety of ecosystems, such as forests, grasslands, lakes, rivers, wetlands, mountains, and hills, which have specific plant and animal species. 11-11-2024 8 India’s Biogeographic Zones 1. The cold mountainous snow-covered Trans Himalayan region of Ladakh. 2. The Himalayan ranges and valleys of Kashmir, Himachal Pradesh, Uttarakhand, Assam, and other North Eastern States. 3. The Terai, the lowland where the Himalayan rivers flow into the plains 4. The Gangetic and Brahmaputra plains. 5. The Thar Desert of Rajasthan. 6. The semi-arid grassland region of the Deccan plateau Gujarat, Maharashtra, Andra Pradesh, Karnataka, and Tamil Nadu. 7. The Northeast States of India, 8. The Western Ghats in Maharashtra, Karnataka and Kerala. 9. The Andaman and Nicobar Islands. 10. The long western and eastern coastal belt with sandy beaches, forests and mangroves. 11-11-2024 9  VALUE OF BIODIVERSITY The world now acknowledges that the loss of biodiversity contributes to global climatic changes. Forests are the main mechanism for the conversion of carbon dioxide into carbon and oxygen. The loss of forest cover, coupled with the increasing release of carbon dioxide and other gases through industrialization contributes to the ‘greenhouse effect’. Biodiversity has aesthetic, recreational, cultural, and spiritual values. Biodiversity provides direct or indirect benefits to people, such as the production of oxygen by plants and algae. Biodiversity is the source of major fuels, including wood and fossil fuels. Biodiversity provides natural products used for food, fodder, timber, and fuel wood. 11-11-2024 10 BIODIVERSITY AT GLOBAL, NATIONAL AND LOCAL LEVELS There are at present 1.8 million species known and documented by scientists in the world. However, scientists have estimated that the number of species of plants and animals on earth could vary from 1.5 to 20 billion! Thus the majority of species are yet to be discovered. Countries with diversities higher than India are located in South America such as Brazil, and South East Asian countries such as Malaysia and Indonesia. While few of the other ‘mega diversity nations’ have developed the technology to exploit their species for biotechnology and genetic engineering, India is capable of doing so. 11-11-2024 11  International agreements such as the World Heritage Convention attempt to protect and support such areas. India is a signatory to the convention and has included several protected Areas as World Heritage sites. These include Manas on the border between Bhutan and India, Kaziranga in Assam, Bharatpur in U.P., Nandadevi in the Himalayas, and the Sunderbans in the Ganges delta in West Bengal. India has also signed the Convention in the Trade of Endangered Species (CITES) which is intended to reduce the utilization of endangered plants and animals by controlling trade in their products and in the pet trade. 11-11-2024 12 HOTSPOTS OF BIODIVERSITY The earth’s biodiversity is distributed in specific ecological regions. There are over a thousand major eco regions in the world. Of these, 200 are said to be the richest, rarest and most distinctive natural areas. These areas are referred to as the Global 200. Our globally accepted national ‘hot spots’ are in the forests of the North-East and the Western Ghats, which are included in the world’s most bio rich areas. The Andaman and Nicobar Islands are extremely rich in species and many subspecies of different animals and birds have evolved. Coral reefs in Indian waters surround the Andaman and Nicobar Islands, Lakshadweep Islands, the Gulf areas of Gujarat and Tamil Nadu. They are nearly as rich in species as tropical evergreen forests! 11-11-2024 13 THREATS TO BIODIVERSITY Due to this ‘unsustainable’ resource-use, once productive forests and grasslands have been turned into deserts and wasteland have increased all over the world. Mangroves have been cleared for fuelwood and prawn farming, which has led to a decrease in the habitat essential for breeding of marine fish. Wetlands have been drained to increase agricultural land. The current destruction of the remaining large areas of wilderness habitats, especially in the super diverse tropical forests and coral reefs, is the most important threat worldwide to biodiversity. Scientists have estimated that human activities are likely to eliminate approximately 10 million species by the year 2050. 11-11-2024 14 ENDANGERED AND ENDEMIC SPECIES OF INDIA The endangered species in the country are categorized as Vulnerable, Rare, Indeterminate and Threatened. Other species are found only in India and are thus endemic or restricted to our country. Some of these may have very localized distribution and are considered highly endemic. To protect endangered species India has created the Wildlife Protection Act. 11-11-2024 15 CONSERVATION OF BIODIVERSITY: INSITU AND EX-SITU In-situ conservation : Biodiversity at all its levels, genetic species and as intact ecosystems, can be best preserved insitu by setting aside an adequate representation of wilderness as ‘Protected Areas’. These should consist of a network of National Parks and Wildlife Sanctuaries with each distinctive ecosystem included in the network. Such a network would preserve the total diversity of life of a region. The objective of these areas should be expanded to the preservation of relatively intact natural ecosystems, where biological diversity – from microscopic unicellular plants and animals, to the giant trees and major mammals – can all be preserved. 11-11-2024 16 Wildlife Sanctuaries and National Parks of India There are 589 Protected Areas in India of which 89 are National Parks and 500 are Wildlife Sanctuary. The Great Himalayan National Park is the largest sanctuary in this ecosystem and is one of the last homes of the beautiful snow leopard. Dachigam Sanctuary is the only place where the rare Hangul or Kashmir stag is found. There are several Sanctuaries in the Terai region, Kaziranga National Park is the most famous which has elephant, wild buffalo, gaur, wild boar, swamp deer, and hog deer, in large numbers, as well as tiger and leopard. Its bird life is extremely rich and includes ducks, storks. Bharatpur is one of the most famous water bird sanctuaries in the world. 11-11-2024 17 The need for an Integrated Protected Area System (IPAS) The International Union for Conservation of Nature and Natural Resources states that it is essential to include at least 10% of all ecosystems as Protected Areas if biodiversity is to be conserved in the long-term. India has only 5% of land in its 589 Protected Areas in 2004. A major strategy to reduce impacts on the biodiversity of the PAs should be to provide a sustainable source of resources for local people living around them. A carefully designed management plan which incorporates an ‘Eco development’ component aimed at providing a source of fuel wood, fodder and alternate income generation for local people, is an important aspect of PA management. 11-11-2024 18 Ex-situ conservation There are situations in which an endangered species is so close to extinction that unless alternate methods are instituted, the species may be rapidly driven to extinction. This strategy is known as ex-situ conservation, i.e. outside its natural habitat in a carefully controlled situation such as a botanical garden for plants or a zoological park for animals, where there is expertise to multiply the species under artificially managed conditions. In India, successful ex situ conservation programs have been done for all our three species of crocodiles. This has been highly successful. 11-11-2024 19 11-11-2024 20