Botany: BIODIVERSITY

Who coined the term biodiversity

EDWARD WILSON

3 levels of biodiversity

1- GENETIC BIODIVERSITY

2- SPECIES BIODIVERSITY

3- ECOLOGICAL BIODIVERSITY

examples of genetic diversity

Examples include 50,000 varieties of rice, 1,000 varieties of mango, and Rauwolfia vomitaria for its active chemical, reserpine.

What is species richness

Species richness refers to the number of different species per unit area. species divesity increases if species richness is high.

Species eveness

Species evenness measures the relative abundance of different species in a given area, indicating how evenly individuals are distributed among those species.

A more conservative and scientifically sound estimate of global species is at about 7 million was given by

ROBERT MAY

No. of species of birds in Columbia, New Yok , Greenland and India

1. COLUMBIA - 1400

2. NEW YORK - 105

3. GREENLAND - 56

4. INDIA - 1200

Species area relationship equation and type of graph formed

log S = log C + Z log A

S= speciess richness , Z= slope of line, C= Y-intercept, A= area

Graph is RECTANGULAR HYPERBOLA.

Value of Z for a normal taxanomic group, large area

Z for normal lies between 0.1-0.2

Z for large area lies between 0.6-1.2

z for frugivores and mammals in tropical forests is 1.15

Characteristics of stable community

1. does not show much variation in year to year productivit

2. resistant or resilient ot occasional disturbance

3. resistant to invasion by aliens

This was said by DAVID TILMAN

Who gave the Rivet Popper hypothesis

PAUL EHRLICH

Acc. to IUCN which all species are present on the Red list (2004)

Total no. of species that are extinct are 784 species which include

338 vertebrates,359 invertebrates and 87 plants

Animal species that went extinct with their place of origin

1. Dodo - Mauritius

2. Quagga - Africa

3. Thylacine - Australia

4. Stellers sea cow - Russia

5. 3 sub species of tiger - Bali,Javan and Caspian

Percentage of different species facing extinction are

Birds - 12 percent

Mammals - 23 percent

Amphibian - 32 percent

Gymnosperms - 31 percent

examples of endangered species

Asiatic lion, Bengal tiger, Lion-tailed macaque, Nilgiri langur, Gangas river dolphin

What are the kinds of evil quartet

1. Habitat loss and fragmentation

2. Over-expolitation

3. Alien species invasion

4. Co-extinction

Example of habitat loss and fragmentation

1. Tropical rain forestonce covering 14 percent but now only 6 pecent

2. The amazon rainforest

Examples of over exploitation

1. Stellers sea cow

2. passenger pegion

3. Marine fish

Examples of alien species invasion

1. Nile perch- introduced in lake victoria in east africa lead to extinction of cichlid fish

2. Water hyacinth(Eichhornia)- introduced in indian water resulting in death of aquatioc plant and animals

3. Lantana and Paienthum caused enviromental damage

4. African catfish(Clais gariepinus) illegally introduced is posing threat to indian catfish

2 reasons why amazon forest has lost most of its biodiversity

1. Many plants are cut for cultivation of soyabean

2. Forest are cinverted to grassland for raising beef cattle

Narrow utilitarian

Cereals,pulses,fruits,firewood,fibre,construction material,tannins,lubricants,dyes,resins,perfumes and product of medical importance

Broadly utilitarian

1. Production of oxygen

2. Pollination of flowers

3. Control of flood and soil erosin

4. Aesthetic pleasure

In situ conservation

Conservation of all the biological wealth for the ecosystem for a particular species

eg: 1. BIODIVERSITY HOTSPOTS ( 25 hotspots but now 34 in india) ; hotspots in india lie in western ghats and srilanka, Indo-burma and eatern himalayas

2. PROTECTED AREAS ; in india their are 90 national parks, 448 wildlife sancturies and 14 biospheres; sacred groves are found in Khasi and jaintia hills in meghalaya,Aravalli hills of rajasthan,western ghats of karnataka and maharastra and the sarguja,chanda and bastar of MP.

Ex situ conservation

Placing the threatened aniaml or plant in a special area

1. india has 335 parks and 35 botanical gardens

2. seed banks, tissue culture and crysopreservation