its explains biodiversity and different types of biodiversity also habitat loss and ho it occurs and its effects and causes

1. SEMINAR
EDU 14.2 ENVIRONMENTAL EDUCATION
TOPIC-Extinction of species, Loss of habitat
and biodiversity

2. Contents
• Extinction of species
• Example -Lazarus taxa
• Natural causes of extinction
• Human causes of extinction
• Types of species extinction
• Loss of habitat
• Major kinds of habitat loss
• Main causes of habitat loss
• Impact of environment degradation
• Biodiversity
• Types of biodiversity

3. Introduction
Extinction is the termination of an organism or
of a group of organisms, normally a species.
The moment of extinction is generally
considered to be the death of the last individual
of the species. There are natural as well as
human causes for extinction.Habitat loss is due
to destruction , fragmentation or degradation of
habitat. Habitat destruction, habitat
fragmentation and habitat degradation are the
major kinds of habitat loss.Biodiversity refers to
the veriety of life.The 3 types of biodiversity are
genetic, species and ecosystem diversity.

4. • Extinction takes place when the last number
of a species dies.
• Extinction of species may come suddenly
when an otherwise healthy species is wiped
out completely due to toxic pollution.
• It is estimated that over 99.9 of all species
that ever lived are extinct.
• The average span of most of the species is 10
million years.
Extinction of species

5. • In biology and ecology,extinction is the
termination of an organism or of a group of
organisms (taxon),normally a species.
• The moment of extinction is generally
considered to be the death of the last
individual of the species.
• More than 99 percentage of all species,
amounting to over 5 billion species that
ever lived on earth are estimated to be
extinct.

6. •A typical species becomes extinct
within millions of years of its first
appearance, although some species
called living fossils,survive with
virtually no morphological change
for hundreds of millions of years.
•Mass extinctions are relatively rare
events; however isolated
extinctions are quite common.

7. • In ecology , extinction is often used to
refer local extinctions,in which a species
ceases to exist in the chosen area of
study, but may still exist elsewhere. This
phenomenon is known as extirpation.
• Species which are not extinct are
termed extant.
• Those that are extant but threatened by
extinction are referred to as threatened
or endangered species.

8. Example -Lazarus taxa
• The coelacanth,a fish related to lungfish
and tetrapods was considered to have
been extinct since the end of the
cretaceous period until 1938 when a
specimen was found off the chalumna
river on the east coast of South Africa.

9. Natural causes of extinction
•Climatic heating and cooling.
•Changes in sealevels or currents.
•Cosmic radiation.
•Acid rain.
•Disease /epidemic.
•Spread of invasive species.

10. Human causes of extinction
•Increased human population.
•Destruction or fragmentation of
habitat pollution.
•Climatic change.
•Global warming.

11. Types of species extinction
•Diversity independent extinction
•Diversity dependent extinction
•Mass extinction
•Absolute extinction
•Pseudo extinction

12. Loss of habitat
• Habitats the place where the organisms live.
• Habitat is the natural home or environment
of animals, plants or other organisms.
• Habitat loss is the loss area or natural place
of an organism.
• It is due to destruction, fragmentation or
degradation of habitat.

13. Major kinds of habitat loss
•Habitat destruction.
•Habitat fragmentation
•Habitat degradation

14. Habitat destruction
•People directly destroy habitat
include filling in wetlands,
dredging rivers,moving fields,and
cutting down trees.

15. Habitat fragmentation
• Aquatic species habitats have been fragmented
by dams and water diversions.
• These fragments of habitats may not be large
enough to support species that need a large
territory where they can find mates and food.
• The loss and fragmentation of habitats make it
difficult for migratory species to find species to
rest and feed along their migration routes.

16. Habitat degradation
• Pollution,invasive species and disruption
of ecosystem processes are some of the
ways habitats can become so degraded,
they no longer support native wildlife.

17. Main causes of habitat loss
• Agriculture
• land conversion for development
• Water development
• Pollution
• Climate change

18. Agriculture
• Much of the habitat loss from
agriculture was done long ago when
settlers converted forests and prairies to
cropland

19. Land conversion for development
• The conversion of lands that once
provided wildlife habitat to housing
developments, roads, office parks, strip
malls, parking lots and industrial sites
continues, even during the current
economic crisis.

20. Water development
• Dams and other water diversions siphon
off and disconnect waters, changing
hydrology and water chemistry.

21. Pollution
• Freshwater wildlife are most impacted by
pollution.
• Pollutants such as untreated sewage,
mining waste, acid rain, fertilizers and
pesticides concentrate in rivers, lakes and
wetlands and eventually end up in estuaries
and the food web

22. Climate change
• The emerging driver of habitat loss is
climatic change.

23. Impact of environment degradation
• Ozone depletion
• Acid rain
• Depletion of marine life
• Loss of forests
• pollution of ground water
• Soil erosion
• Air pollution
• Global warming

24. Biodiversity
• Bio means life and diversity means veriety
• Biodiversity refers to the veriety of life.
• It is seen in the number of species in an
ecosystem or on the entire earth.
• The term biological diversity was first used
by wildlife scientist and conventionalist
Raymond F Dasmann in 1968.
• It was widely adopted only in the 1980s.

25. • Biodiversity is important in human managed
as well as natural ecosystems.
• Biodiversity is the variability among living
organisms from all sources,including
terrestrial, marine and other aquatic
ecosystems and the ecological complexes of
which they are part.
• Bidiversity includes diversity within species,
between species and ecosystems.
• Biodiversity forms the foundation of the vast
array of ecosystem services that critically
contribute to human well-being.

26. • There are many measures of biodiversity,
species richness (the number of species in a
given area )represents a single but important
matric that is valuable as the common
currency of the diversity of life-but it must be
integrated with other matrics to fully capture
biodiversity.
• Ecological indicators are scientific constructs
that are quantitative data to measure aspects
of biodiversity.

27. Types of biodiversity
1. Genetic diversity
2. species diversity
3. Ecosystem or community diversity

28. 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.
• For example, each human being is very
different from all others.
• This genetic variability is essential for a
healthy breeding population of a species

29. • If the number of breeding individuals is
reduced, the dissimilarity of genetic
makeup is reduced and in-breeding occurs.
• The diversity in wild species forms the 'gene
pool' from which our crops and domestic
animals have been developed over
thousands of years
• Modern biotechnology manipulates genes
for developing better types of medicines
and a veriety of industrial products.

30. Species diversity
• Species is a basic unit of classification and is
defined as a group of similar organisms that
mate and produce offsprings with one another
and thus share a common lineage.
• 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

31. • Some areas are richer in species than
others.
• Natural undisturbed tropical forests have
much greater species richness than
plantations.

32. Ecosystem or community diversity
• Ecosystem diversity can be described for a
specific geographical region, or a political
entity such as country, a state or a taluk.
• Distinctive ecosystems include landscapes
such as forests,grasslands, deserts
,mountains as well as aquatic ecosystems
such as rivers, lakes and the sea

33. • Ecosystems are most natural in wilderness
areas.
• If natural ecosystems are overused or
misused their productivity eventually
decreases and they are then said to be
degraded.
• India is exceptionally rich in ecosystem
diversity.
• community diversity has 3 perspectives -
alpha diversity, beta diversity and gamma
diversity.

34. Alpha diversity
• It is the biodiversity within a particular area,
community or ecosystem.
• It is usually expressed by the number of
species (species richness )in that
ecosystem.
• This can be measured by counting the
number of taxa (distinct groups of
organisms )within the ecosystem (for
example, families, genera and species.

35. Beta diversity
• Beta diversity is a measure of biodiversity
which works by comparing the species
diversity between ecosystems or along
environmental gradients.
• This involves comparing the number of taxa
that are unique to each of the ecosystems.
• It is the rate of change in species composition
across habitats or among communities.
• It gives a quantitative measure of diversity of
communities.

36. Gamma diversity
• It refers to the total species richness over a
large area or region.
• It is a measure of the overall diversity for
the different ecosystems within a region.
• It is the product of a diversity of component
ecosystems and the diversity between
component ecosystems

37. • Gamma diversity can be expressed in terms
of the species richness of component
communities as follows :
• Y=S1+S2-C
• Where S1=the total number of species
recorded in the first community.
• S2=the total number of species recorded in
the second community.
• C=the number of species common to both
communities.

38. Conclusion
Extinction is the termination of an organism or
of a group of organisms, normally a species. The
moment of extinction is generally considered to
be the death of the last individual of the species.
There are natural as well as human causes for
extinction.Habitat loss is due to destruction ,
fragmentation or degradation of habitat. Habitat
destruction, habitat fragmentation and habitat
degradation are the major kinds of habitat
loss.Biodiversity refers to the veriety of life.The
3 types of biodiversity are genetic, species and
ecosystem diversity.