2. 1. Levels of biodiversity
2. Number of species on earth
3. Patterns of biodiversity
4. Loss of biodiversity
5. Biodiversity conservation
3. Biological diversity is the variety and
variability of life on Earth. Biodiversity
is a measure of variation at the
genetic, species, and ecosystem level.
“Edward O. Wilson known as the
father of biodiversity”.
5. Diversity shown by a single species at genetic level.
Different gene and combination of gene within a
populations.
E.g. Rauwolfia vomitoria (Himalaya) shows genetic
variations in potency and concentration of the
chemical reserpine.
It used as traditional medicine, in diarrhea, jaundice,
venereal disease, rheumatism, snake-bites, colic,
fever, to calm people with anxiety or epilepsy, and to
lower blood pressure.
1.GENETIC LEVEL
6. Other example of genetic biodiversity is,
India has more than 50,000 different strains of rice and 1000 varieties of mango.
7. 2.SPECIES LEVEL
Number of variety of species in particular area
or in world.
E.g. western ghat have greater amphibian
species diversity than eastern ghat.
8. 3.ECOSYSTEM LEVEL
Diversity between ecosystems within a geographical location.
E.g. desert, rainforest, mangroves, estuaries, coral reefs, wetland, alpine
meadows etc.
9. NUMBER OF SPECIES ON EARTH ( GLOBAL SPECIES DIVERSITY)
Global biodiversity is the measure of biodiversity on planet Earth and is
defined as the total variability of life forms.
According to IUCN, (2004)
(International Union for Conservation of Nature) more than
1.5 million species described so far. In tropical region
many species not discovered yet.
According to Robert May, global species diversity is
about 7 million. While other scientists believe
it would range from 20-50 million.
10. TOTAL NUMBER OF SPECIES ON EARTH ( GLOBAL SPECIES DIVERSITY)
Out of total species discovered
Above 70% are animals and
22 % are plants ( including fungi).
Among 70% animals, Insect are
most species rich group.
i.e. out of every 10 animals , 7 are
insects.
Number of fungi is more than the
combined total of species of fishes,
amphibians, reptiles, and mammals.
11. GLOBAL LEVEL BIODIVERSITY OF INDIA
India has only 2.4 % of the world’s
land area, but 8.1 % of the species
diversity.
India is one of the 12 mega diversity
countries (8 rank).
India with Nearly 45000 species
(22%) of plants and twice as many
of animals.
By applying may’s global estimate
India would have more than 1 lakh
plant species and 3 lakh animals
species.
Biologist are not sure about
total number of prokaryotic
diversity , because
Conventional taxonomic
methods are not suitable for
identifying microbial
species.
In laboratory, many species
can not be cultured.
12. Patterns of biodiversity
1. Latitudinal gradients
The pattern of having lots of species
at the equator with diversity
dwindling off towards the poles is
known as the Latitudinal Diversity
Gradient.
Species diversity decreases from the
equator to the poles.
The tropics (between 23.5 N to
23.5°S) have more species than
temperate or polar areas.
13. EXAMPLE OF LATITUDINAL GRADIENTS
1. Number of birds species
Colombia (near equator): about 1400
species
New York (41o N): 105 species
Greenland (71o N): 56 species
India (in tropics): > 1200 species
Tropical forest region like equador
has 10 times of vascular plants
species as compared to a temperate
forest region like Midwest of USA.
14. DIVERSITY AMAZONE RAIN FOREST OF SOUTH AFRICA
It has a greatest biodiversity in the
world
Plants - >40000
Fishes - 3000
Birds – 1300
“THE LUNGS OF THE EARTH”
Mammals – 427
Amphibians – 427
Reptile – 378
Invertebrates - >125000
Because they are responsible for the production
of about 20% of the earth's oxygen.
15. Reasons for highest biodiversity (species richness) in the tropics
1)Tropics had long evolutionary time
(frequent glaciation).
2)Tropical environments are less
seasonal (more constant and
predictable).
3)There is more solar energy available
in the tropical regions. (had a great
productivity).
16. 2. Species-area interaction
Alexander von Humboldt
(German naturalist and
geographer)
study wilderness of south
American jungles, within a
region,
species richness increase with
increasing explored area, but
only up to a limit.
Species richness ∝ area
S ∝ A
17.
18.
19. IMPORTANCE OF SPECIES DIVERSITY
Parameters or important aspects
of species diversity
1) Productivity variations.
2) Stable community resistant to
occasional disturbance.
3) Stable community resistant to
invasions by alien species.
According to David Tilman, plots with more species shows less year to
year variation in total biomass.
Increased diversity contributes to higher productivity. It is essential for
ecosystem health and survival of human race on the planet.
20. RIVET POPPER HYPOTHESIS/ AIROPLANE REMOVE HYPOTHESIS
It was given by Stanford ecologist Paul enrlich.
He used an analogy to understand the importance of
biodiversity.
Ehrlich asks us to imagine a plane (ecosystem) that
is fully functional.
21. In an airplane (ecosystem) all parts are
joined together using thousands of rivets
(species).
If every passenger travelling in it starts
popping a rivet to take home (causing a
species to become extinct),
it may not affect flight safety (proper
functioning of the ecosystem) initially, but as
more and more rivets are removed,
the plane becomes dangerously weak over a
period of time.
22. Loss of rivets on the wings (key species
that drive major ecosystem functions) is
obviously a more serious threat to flight
safety than loss of a few rivets on the
seats or windows inside the plane.