VCE Environmental Science: Unit 3: Biodiversity. Introduction that explains the definitions and reasons to conserve biodiversity on a genetic, species and ecosystem level.

1. Unit 3 VCE
Environmental Science
Area of Study 2: Biodiversity
Britt Gow, 2012

2. Definition:
• Biodiversity (biological diversity) is the total sum of
all the living organisms that exist on our earth.
• This living wealth is the product of hundreds of
millions of years of evolutionary history.
• “The variability among living organisms from all
sources including terrestrial, marine and other
aquatic ecosystems and the ecological complexes
of which they are a part; this includes diversity
within species, between species and of
ecosystems” International Convention on
Biological Diversity.

3. Biological Diversity
• Today's biodiversity is the result of billions of years of
evolution, natural processes, and in more recent years,
human activity. Before Homo sapiens, the Earth's
biodiversity was much greater than it is today. Human
activity has had a tremendous impact on biodiversity
due to use of Earth's resources and exponential
population growth.
• The total number of species on Earth today is
estimated to be around 10 million different species,
but could be as low as 2 or as high as 100 million. New
species are discovered often, and many that have been
discovered have not yet been classified. The richest
sources of biodiversity on Earth are found in tropical
rainforests and the ocean.

4. Three Levels:
• Genetic Diversity – genes on chromosomes
determine the specific characteristics
(physical, emotional) of individual organisms.
Diversity of genes within a species and processes
such as mutations, gene exchanges, and genome
dynamics that occur at the DNA level and
generate evolution.
• Species Diversity – variety of different types
(species) of organisms
• Ecosystem Diversity – variety of different
ecosystems from marine to desert to tropical
rainforest to temperate Eucalypt forest to
wetlands etc.

5. http://www.epa.gov/eerd/APMnew.htm

6. Genetic Diversity
• The reason captive breeding programs need to
introduce new individuals from wild populations.
• a species with high genetic diversity will tend to
produce a wider variety of offspring, where some of
them may become the most fit variants.
• In contrast, a species that has little or no genetic
diversity will produce offspring that are genetically
alike and therefore will likely be susceptible to
diseases or problems similar to those of their parent.
• Hence, little or lack of genetic diversity reduces
biological fitness and increases the chances of
species extinction.
• Larger populations have greater genetic diversity and
are therefore less vulnerable to change and more
adaptable and sustainable.

7. Geneticists are working to improve
our food crops by making them
less vulnerable to disease, drought
and crop failure. Humans need to
provide food for a growing
population by increasing
productivity.
Genetic studies show that
the cheetah has a very low
genetic diversity, indicating
that the population has
crashed to about 200
individuals at some time in
the past. They are
vulnerable to extinction for
this reason.

8. Species
Diversity
can be measured by
counting the number of
organisms of each
species.
“The existence of a wide
range of different types of
organisms in a given place
at a given time. The
diversity of plant and
animal life in a particular
habitat.”

9. Ecosystem Diversity
• Variety of habitats, living communities and
ecological processes in the living world.
• Includes alpine, dry-schlerophyll, mallee,
tropical rainforest, savannah (grassland),
freshwater aquatic, temperate marine,
Antarctic etc, each with it’s own
characteristic species and food webs.
• Often preserved by National parks and
reserves.

10. Australian Biodiversity
• Australia has an incredibly diverse range
of life due to it’s isolation from other
continents.
• Australia is recognised as one of the most
mega-diverse countries on the planet, with
many endemic species, such as our iconic
marsupials and monotremes, banksias,
eucalypts and grevilleas.

13. Why Conserve Biodiversity?
• Ecosystem services
• Biological resources
• Social benefits

14. Products Services Social
Benefits
Plants (trees,
grasses, palms,
herbs)
Fungi
Micro-organisms
Invertebrates
Vertebrates

16. Conservation of Biodiversity
• Genetic – variety of breeding pairs in captive
programs, different groups in separate locations
• Population – conserving a particular population
within a precise geographic area
• Species – preserving different species of organisms
(management plans)
• Ecosystem – National parks and conservation
reserves

17. Assessment of Biodiversity
• Species richness (no. of different species)
• Species diversity (abundance of each different
species)
• Simpson’s Index
• Shannon-Weiner Diversity Index

18. Threats to Biodiversity -
CHIPPO
• Climate Change
• Habitat destruction
• Introduced animals
• Pollution
• Pest plants
• Over-harvesting

20. IUCN Conservation
Categories
• Extinct
• Extinct in the wild
• Critically endangered
• Endangered
• Vulnerable
• Conservation dependent
• Data deficient
• Low risk
• Not evaluated

21. Strategies for protecting
Biodiversity
• Action plans
• Captive breeding programs
• Conservation reserves
• Revegetation and habitat restoration
• Feral species control
• Ecotourism
• Education

22. Project Eden: Shark Bay, WA

25. Keeping Feral Species Out