Biodiversity• The sum total of genes, species and ecosystems of a

given region is called biodiversity.

• The term biodiversity was coined by Edward wilson.

• Levels of biodiversity: The biodiversity is studied in three levels.

1. Genetic biodiversity.

2. Species biodiversity.

3. Ecological biodiversity.

• Genetic biodiversity: Variation of genes found with in a species is called gene diversity.

• Ex: There are more than 50,000 genetically different strains of rice and 1000 varieties of mango are in India.

• Species biodiversity: The variety of species found in a habitate is called species biodiversity.

• Ex: The Western Ghat has greater diversity of amphibian species than Eastern Ghat.

• Ecological biodiversity: The variety of different habitate found in the particular area is called ecosystem biodiversity.

• Global Biodiversity: According to IUCN (2004) the total number of plant and animal species described is about 1.5 million.

• It is estimated that global biodiversity has 7 million species.

• More that 70% of all species recorded are animals. Plants account for about 22% of the total.

• Insects are more species rich group. 70% of the animal are insects.

Measurement of biodiversity.

• Biodiversity is measured in three ways,

1. α-Biodiversity: It refers to number of species found in the particular area.

2. β- Biodiversity: It is the comparison of biodiversity between two habitats.

3. γ- Biodiversity: It is the measure of overall biodiversity in large land scale.

• Importance of Species Diversity to Ecosystem:

• Communities with more species tend to be more stable than those with less species.

• A stable community has following characters,

• Productivity should not vary too much from year to year.

• It should not show too much variation

• It has resistance to seasonal disturbances and to invasion by alien species.

• Losses of biodiversity:

• The four major causes of biodiversity loss are,

1. Habitat loss :– Habitat loss is the destruction of ecosystem by unwanted human activities such as urbanization, intensive farming, deforestation, mining activities and so on.

• When the vegetation is cleared for human activities the continuous habitats become fragmented. This is called habitat fragmentation.

Degradation of natural habitats are threatening the species.

2. Over-exploitation :– It is the harvesting of renewable resources to the extent.

3. Alien species :– Invasion of alien species in the natural habitats cause decline in the native species.

4. Co-extinction :– when one organism becomes extinct , the other associated obligatory species also tend to extinct.

Endemic species:• The species that confined to particular area is

called endemic species.

– Important endemic species of India are,

–

It is reported from Western Ghats of Tamil Nadu, Kerala and Tamil Nadu.It was originally misidentified as a short-nosed fruit bat but later identified by Kitti Thonglongya Bangkok as a new species and was named after Indian ornithologist Salim Ali in 1972.

• The Nilgiri Langur found in the Nilgiri Hills of the Western Ghats in South India.

• Its range is Kodagu in Karnataka, Kodayar Hills in Tamil Nadu and many other hilly areas in Kerala.

The species is reported from the Nilgiris, parts of southern Kodagu and northern Kerala, up to the Charmadi ghats.

The brown palm civet's distribution extends from the southern tip of Western Ghats in Kalakkad Tiger Reserve ( Tamilnadu -kanyakumari ) to Castle Rock in Goa .They are nocturnal carnivore.

Madras Shrew distributed in Western Ghats

• Biological hotspots: Biological hotspots are natural environment with high biodiversity and endemic species.

• Among 34 hotspots of world, the two biodiversity hotspots of India are western Ghats and Eastern Himalayas.

Threatened species: The species whose population number is decreasing and likely to decrease more in future is called threatened species.

• IUCN: International union for conservation of nature and natural resource.

• Red Data Book: The book maintained by IUCN in which threatened species are recorded is called red data book.

• MAB: Man and Biodiversity Programme

• WWF: The World Wildlife Fund for nature

• IBWL: Indian Board for Wildlife

• IBP: International Biological Programme

• UNDP: United Nation Development Programme.

• Major categories of threatened species:

• Extinct species: The species that completely disappeared from earth are called extinct species.

• Endangered species: The species whose population is drastically reduced and are in danger of extinction are called endangered species. Ex: Asiatic lion, One horned rhinoceros. Lion tailed macaque. Nilgiri tahr.

• Vulnerable species: The species that likely enters the endangered category are called vulnerable species.

• Ex: wild goat. Wild yak. Barasinga. Wild ass, etc.

• Rare species: the species with small population which are neither endangered nor vulnerable are called rare species.

• Approaches to Biodiversity conservation

• Conservation of biodiversity is done by two methods:

• In-situ conservation: It is the conservation of wildlife within their natural habitat.

• Ex: National parks, sanctuaries and biosphere reserves.

• Ex-situ conservation: It is the conservation of wildlife outside their natural habitat.

• Ex: Zoo, Botanical garden, Seed bank etc.

• Ethical believes play imp role in conservation of biodiversity.

• Sacred species: The traditionally conserved species of plant and animals on religious believes are called sacred species.

• Ex: cow, snake, monkey, elephant, tulasi, neem, banyan tree, etc.

• Sacred groves: Traditionally conserved patches of forest that dedicated to local deity are called sacred groves.

• Ex: Devara kadu. Nagarabana, Boothasthana, Devabana etc.

• Sacred landscape: It is the traditionally conserved land areas with its natural features. In these areas human activities and hunting is banned. It includes forest, grass land, rivers, ponds etc.

• Ex: kodachdri hills at kollur. Biligiri ranganatha hills. Etc.

• Biodiversity depletion: The reduction or loss of plants and animals of biodiversity is called biodiversity depletion. It causes due to natural disasters and human activity.

• Anthropocentric causes of biodiversity depletion:

• The cause of biodiversity depletion due to human activity is called Anthropocentric causes. These are ,

1. Urbanization.

2. Expansion of agriculture.

3. Deforestation.

4. Pollution.

5. Acidification of soil and water.

6. Soil erosion.

7. Mining activity.

8. Desertification.

• Deforestation: The destruction of forest for agriculture, industrial or domestic use is called Deforestation.

• It leads to loss of habitat, soil erosion, Desertification, global worming, and biodiversity depletion.

• Acidification of soil and water: The decrease in pH value of soil and water is called Acidification of soil and water.

• It causes due to acid rain usage of high chemical fertilizer. Mining activity, industrialization, etc.

• Most of the soil microbes, insect, plants aquatic animals are sensitive to acidic condition. Hence acidification leads to biodiversity depletion

• Mining activity: It is the extraction of non renewable geological materials from earth. It results in,

1. Exploitation of non renewable resource.

2. It brings deforestation.

3. It causes air, water soil and noise pollution.

4. It causes soil erosion.

5. It result in biodiversity depletion.

• The smoke combines with fog and forms smog.

• It destroys the plant vegetation.

• In human beings smog causes respiratory disorders and asthma.

Biosphere reserves:• The large undisturbed area where the wild life is protected in their

natural habitat is called biosphere reserves.

• The biosphere reservoir is divided into 3 zones:

• 1. Core zone: Inner most area of biosphere reservoir where human activity is prevented.

• 2. Buffer zone: It is out side the core zone where human activity is permitted.

– In buffer zone I, publics are not allowed, only research activities to wild life is allowed.

– In buffer zone II public can enter for the purpose of observing wild life. The traditional activity like collection of fruit, seeds honey are allowed.

• 3. Transition zone: Agricultural activities are noticed in this area. Soil erosion, deforestation and over grazing are common in this area.

National park• National parks are protected

areas which is strictly reserved for conservation of wild life. The human activity, grazing, cultivation are strictly banned in this area.

Imp national parks of India.

• Bandipur national park in Karnataka. Protected animals are elephants and tigers.

• Kaziranga national park at Assam. Protected animals are one horned rhinoceros.

• Sundarbans national park at West Bengal. Protected animals are Bengal tigers. Ridley sea turtle

• Kanha national park at madya Pradesh. Protected animals are Swamp deer.

• Gir national park at Gujarat. Protected animals are Asiatic lion.

• Manasa national park at Himalaya foothills. Protected animals are tigers, rhinoceros, elephants.

• Ranathambore national park at Rajasthan. Protected animals are tigers, leopards, Wild Boars.

• Dachigam national park at Jammu- Kashmir. Protected animals are Hangul (Kashmir stag)

Sanctuaries :• These are the smallest area than the national parks.

In this area human activity is allowed to collect fruits, seeds, honey, animal grazing etc.

• Wildlife sanctuaries of India.

• Ranganthittu bird sanctuary in Karnataka. Assembled species of birds are protected.

• Badra wildlife sanctuary in Kanata. The protected animals are Tigers.

• Periyar wildlife sanctuary at Kerala. The protected animals are elephants.

• Annamalai wildlife sanctuary at Tamil nadu. The protected animals are Tigers.

Zoological garden:

• The zoo are the place where different endangered animals are protected.

1. Chamarajendra zoological park at Mysore.

2. Bannergatta zoological park at Bangalore.

3. Pilikula zoological park at Mangalore.

4. Lion safari in talaguppa shimoga

• IBWL: Indian board of wild life.

• WWFI: world wild life India.

Global issue:

• Biodiversity depletion and ecological imbalance is discussed in international level is called global issue concerned to environment.

• The major global issue are

• Global warming.

• Acid rain formation.

• Ozone depletion.

• Nuclear winter.

• Global warming: the progressive increase in temp of earth due to increase in green house gases is called global warming.

• The green house gases like CO2,oxides of nitrogen, oxides of sulphur, methane and water vapors traps the infra red rays that reflects back. This increases the atmospheric temp.

The solar spectrum of electromagnetic waves include energy packed heat generating waves called radiation waves. As they lie beyond red color waves of visible spectrum, they are also called 'infra-red rays'. These infrared rays lie in the wave length range of 700-900 mm.

Effect of global warming.• The sea level rises due to

melting of ice caps at polar region.

• It reduces agricultural yields.

• Alters the rainfall patterns due to variations in the convectional current, caused by difference in heating pattern of earth's air.

• Change or shifts in seasons and seasonal characters through out the globe.

• Control measures.

• Adopting afforestation and reforestation programs.

• Reducing in use of fossil fuel.

• Using renewable energy resource like solar energy, wind energy, tidal energy etc.

Ozone layer depletion.

• Ozone is the alternative form of oxygen molecule. It is O3. The ozone layer is present in the stratosphere is about 25 km above the earth surface.

• It is a protective layer protects life on earth by preventing UV rays, alpha, beta, and gama rays present in solar rays.

• The thickness of the ozone is measured by an instrument Ozone mapping spectrometer.

• The reduction in thickness of ozone layer leads to ozone depletion and ozone hole.

• Through these holes harmful radiations reaches the earth. It destroys the life and biodiversity.

• 16th sep is celebrated as world ozone day to create awareness about ozone layer depletion

• The ozone layer is depleting due to chloro fluro carbon. Halogenated hydrocarbons, carbon tetra chloride etc.

Effect of ozone layer depletion.

• It increases the influx of UV radiation to earth surface.

• The UV rays are harmful to plants and animals.

• The harmful rays causes skin cancer, skin burn etc.

• These rays causes mutation by damaging DNA.

• It effects crop yield.

• It destroys the ovum and larva of amphibians

Nuclear winter.• It is the hypothetical climatic condition of earth that could

be outcome of nuclear war. • The nuclear war if occurs in future causes nuclear winter.The effects of nuclear winter are,• The nuclear explosion set fire storms over cities and

forests.• It generates enormous smoke and dust in atmosphere.• It develops black clouds and prevents the sunlight to reach

earth surface.• This results in fall of surface temp to freezing point.• The semidarkness and freezing temp effects

photosynthesis and destroys vegetation.• The radioactive pollutants causes mutations and cancers in

human beings and other animals.