What is Habitat?
Each species evolves to thrive in its own particular ecological niche - to live in a particular "home" with specific living conditions (including temperatures ranges and other plant and animal species). Some species are more adaptable, or "opportunistic", than others. For example, rats and dogs can survive under many different conditions.
What is Habitat Destruction?
Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity.
What are the main reason?
• Habitat destruction by human activity mainly for the purpose of harvesting natural resources for industry production and urbanization.
• Clearing habitats for agriculture is the principal cause of habitat destruction.
• Other important causes of habitat destruction include mining, logging, trawling and urban sprawl.
Habitat destruction is the main threat to Biodiversity
Habitat destruction is currently ranked as the primary cause of species extinction worldwide. It is a process of natural environmental change that may be caused by habitat fragmentation, geological processes, climate change or by human activities such as the introduction of invasive species, ecosystem nutrient depletion and other human activities.
Human Activities increased Habitat Destruction
Habitat destruction caused by humans includes conversion of land to agriculture, urban sprawl, infrastructure development, and other anthropogenic changes to the characteristics of land.
Habitat degradation, fragmentation, and pollution are aspects of habitat destruction caused by humans that do not necessarily involve overt destruction of habitat, yet result in habitat collapse.
Desertification, deforestation, and coral reef degradation are specific types of habitat destruction for those areas
Present Scenario
· Habitat loss poses the greatest threat to species.
· The world's forests, swamps, plains, lakes, and other habitats continue to disappear as they are harvested for human consumption and cleared to make way for agriculture, housing, roads, pipelines and the other hallmarks of industrial development.
· Without a strong plan to create terrestrial and marine protected areas important ecological habitats will continue to be lost.
· Habitat loss is probably the greatest threat to the variety of life on this planet today
· It is identified as a main threat to 85% of all species described in the IUCN's Red List (those species officially classified as "Threatened" and "Endangered").
· Increasing food production is a major agent for the conversion of natural habitat into agricultural land.
Why is it happening?
· Forest loss and degradation is mostly caused by the expansion of agricultural land, intensive harvesting of timber, wood for fuel and other forest products, as well as overgrazing.
· High land conversion rates
· The net loss in global forest area during the 1990s was about 94 million ha (equivalent to 2.4% of total forests). It is estimated that in the 1990s, almost 70% of deforested areas were converted to agricultural land.
· Around half of the world's original forests have disappeared, and they are still being removed at a rate 10x higher than any possible level of re-growth. As tropical forests contain at least half the Earth's species, the clearance of some 17 million hectares each year is a dramatic loss.
Coastal and marine areas
Human impact on terrestrial and marine natural resources results in marine and coastal degradation. Population growth, urbanization, industrialization and tourism are all factors.
In 1994, it was estimated that 37% of the global population lived within 60 km of the coast. Poverty, consumption and land-use patterns contribute to the degradation of marine habitats and to the destruction of the species that rely on them to survive.
Endangered Species
An endangered species is a population of organisms which is facing a high risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters. The International Union for Conservation of Nature (IUCN) has calculated the percentage of endangered species.
• It has been estimated that over 40% of all living species on Earth are at risk of going extinct.
• Internationally, 199 countries have signed an accord agreeing to create Biodiversity Action Plans to protect endangered and other threatened species.
Categorization
• Extinct
• Extinct in the wild: captive individuals survive, but there is no free-living, natural population
• Critically endangered: faces an extremely high risk of extinction in the immediate future
• Endangered: faces a very high risk of extinction in the near future
• Vulnerable: faces a high risk of extinction in the medium-term
• Near threatened: may be considered threatened in the near future
Endangered Species in India
• According to the Red Data Book of International Union for Conservation of Nature (IUCN), there are 47 critically endangered species in India (As of 5 September 2011)
• The Red list of 2012 (19 July 2012) 132 species of plants and animals as Critically Endangered from India.
Conservation
Conservation is the protection, preservation, management, or restoration of wildlife and natural resources such as forests and water. Through the conservation of biodiversity the survival of many species and habitats which are threatened due to human activities can be ensured. Other reasons for conserving biodiversity include securing valuable Natural Resources for future generations and protecting the well being of eco-system functions.
In-situ and ex-situ conservation
• In-situ: Conservation of habitats, species and ecosystems where they naturally occur. This is in-situ conservation and the natural processes and interaction are conserved as well as the elements of biodiversity.
• Ex-situ: The conservation of elements of biodiversity out of the context of their natural habitats is referred to as ex-situ conservation. Zoos, botanical gardens and seed banks are all example of ex-situ conservation.
Which areas to conserve?
Hotspots of biodiversity - A popular approach for selecting priority areas has been to select hotspots of diversity. Since it is not possible to conserve all biodiversity due to lack of resources and the need to use land for human activities, areas are prioritized to those which are most in need of conservation.
‘Hotspot’ a term used to define regions of high conservation priority combining high richness, high endemism and high threat.
Present scenario in India
• India is one of the 12 mega biodiversity countries in the world. The country is divided into 10 biogeographic regions.
• One of the 12 primary centres of origin of cultivated plants and domesticated animals. It is considered to be the homeland of 167 important plant species of cereals, millets, fruits, condiments, vegetables, pulses, fibre crops and oilseeds, and 114 breeds of domesticated animals.
• About 4,900 species of flowering plants are endemic to the country.
• These are distributed among 141 genera belonging to 47 families.
• These are concentrated in the floristically rich areas of North-East India, the Western Ghats, North-West Himalayas and the Andaman and Nicobar Islands.
• These areas constitute two of the 18 hot spots identified in the world.
• It is estimated that 62 per cent of the known amphibian species are endemic to India of which a majority is found in Western Ghats.
• Approximately 65 per cent of the total geographical area has been surveyed so far.
• Based on this, over 46,000 species of plants and 81,000 species of animals have been described by the Botanical Survey of India (BSI) established in 1890 and Zoological Survey of India (ZSI) established in 1916, respectively.
• Approximately, 4.2 per cent of the total geographical area of the country has been earmarked for extensive in-situ conservation of habitats and ecosystems.
• A protected area network of 85 national parks and 448 wildlife sanctuaries has been created.
• The results of this network have been significant in restoring viable population of large mammals such as tiger, lion, rhinoceros, crocodiles and elephants.
• The Indian Council of Forestry Research and Education (ICFRE) has identified 309 forest preservation plots of representative forest types for conservation of viable and representative areas of biodiversity.
• Out of these plots, 187 area in natural forests and 112 are in plantations, covering a total area of 8,500 hectares.
• Twenty one wetlands, and mangrove areas and 4 coral reef areas have been identified for intensive conservation and management purposes. Mangroves conservation is one of the thrust areas of the Ministry of Environment and Forests.
• Six significant wetlands of India have been declared as "Ramsar Sites" under the Ramsar Convention. Under the World Heritage Convention, five natural sites have been declared as "World Heritage Sites".
• To complement in-situ conservation, attention has been paid to ex-situ conservation measures.
• According to currently available survey, central government and state governments together run and manage 33 botanical gardens.
• Universities have their own botanical gardens.
• There are 275 zoos, deer parks, safari parks and aquaria.
Major central acts relevant to biodiversity include
• Forest Act, 1927,
• Wildlife (Protection) Act, 1972,
• Forest (Conservation) Act, 1980, and
• Environment (Protection) Act, 1986.
• National Forest Policy amended in 1988, National Conservation Strategy and Policy Statement for Environment and Sustainable Development, National Agricultural Policy, National Land Use Policy, National Fisheries Policy, National Policy and Action Strategy on Biodiversity, National Wildlife Action Plan and Environmental Action Plan.
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