Download A biodiversity hotspot is an area containing a - School

Biomass
Biodiversity
is low where
there
are
climatic
extremes
Biodiversity
is greatest in
the tropics
Biodiversity is generally
greatest in the southern
hemisphere
Seventy per cent of the world's species is
found in just 12 countries: Australia, Brazil,
China, Colombia, Costa Rica, Ecuador, India,
Indonesia, Madagascar, Mexico, Peru and
Democratic Republic of Congo
Initially 25 terrestrial hotspots.
Recently updated to include
marine hotspots.
Now 34
hotspot areas identified.
Marine hotspots are essentially coral
reef areas in the tropics (contain 24%
of world’s coral reefs yet cover
0.017% of oceans)
Terrestrial hotspots cover approximately
1.4% of the earth’s surface. Together they
contain 44% of the world’s plants and 35%
of the world’s animal species
Terrestrial and marine hotspots are
often adjacent to each other e.g.
Cape Floristic Province, South Africa
The location of
hotspots does not
correlate
exactly
with the location of
greatest
biodiversity.
For
example,
France
does not have a
particularly
high
biodiversity but yet
its southern shores
are part of the
Mediterranean
Basin Hotspot.
The tropical distribution of both types of hotspot is due to an
absence of limiting factors which allows maximum primary
productivity. In the tropics high temperatures, high humidity,
abundant rainfall, and plentiful nutrients all encourage luxuriant
growth of rainforests and reefs
Madagascar
Mediterranean
Basin
Cape
Floristic
Region
Indo-Burma
Atlantic
forests
South-West
Australia
Species
richness
Level of
threat to
species
Endemic
richness
Biodiversity
hotspot
A biodiversity hotspot is an area containing a
huge number of species, a large percentage of
which are endemic. Hotspots have been
described as ‘the most remarkable places on
Earth and the most threatened’. They cover less
than 2% of the Earth’s surface, yet they contain
44% of the world’s plant species and 35% of its
animal species.
• Continental Hotspots
• Large Island Hotspots
• Small Island Hotspots
• Marine Hotspots
ATLANTIC FOREST
AUSTRALIA
MADAGASCAR
CORAL REEF
Invasive
species
Alterations in
ecosystem
composition
Pollution
Threats to
Biodiversity
Climate
Change
Over
exploitation
Habitat loss
and
destruction
Has ensured that the ‘best bits’- areas with the highest
levels of biodiversity, substantial levels of endemism
(unique/rare species) are conserved and protected.
Areas under threat are commonly in the tropics and in
developing countries where conservation costs are much
lower (cheap labour) – idea of value for money.
Hotspots now covers marine area under threats in addition to
terrestrial ecosystems
Even with the additions of marine hotspots under 2% of the earth
and 0.017% of oceans are protected by this approach
The distribution of areas protected is very uneven. Most hotspots
lie in the tropics e.g. rainforests. Many ecosystems such as Tundra,
Taiga and Temperate Forest are not included.
Huge areas of the world are not covered including many areas under
great threat e.g. Arctic Ocean, or many outstanding smaller regions
such as Galapagos . These are not protected because they do not
meet all three criteria to be a hot spot. Polar bears subsequently
face extinction.
Hotspots tend to follows protectionist approach. This entails
removing people and their activities from areas under threat. This
has occurred in tropical countries where indigenous people have been
forced off their land in favour of creating big reserves.
•IUCN Red List of Threatened Species is considered the
most comprehensive record of the conservation status of
plants and animals.
•Essentially precise criteria is utilised by different countries
and organisations to evaluate the extinction risk of thousands
of species and subspecies.
• These criteria are relevant to all species and all regions of
the world.
• Records are continually being updated.
• The IUCN aim to convey the urgency of conservation
issues to the public and policy makers, as well as help the
international community try and reduce species extinction.
• The Living Planet Index (LPI) is an indicator of the state
of global biological diversity, based on trends in vertebrate
species- fish, amphibians, reptiles, birds mammals- from all
around the world.
• By tracking wild species, the Living Planet Index is also
monitoring the health of ecosystems.
• The information can be used to define the impact humans
are having on the planet and for guiding actions to address
biodiversity loss.
•The WWF developed a system of eco-regions.
• 200 Eco-regions were identified.
• They are deemed the most biologically distinct
terrestrial, freshwater, and marine ecosystems on the
planet and subsequently are to be protected and
conserved to ensure species, habitats and ecological
processes continue.
• The eco-regions identified are to be representative of
all ecosystems of that type.
• World Resource Institute – Earthtrends
• Millennium Assessment
• Find out how they conserve biodiversity. Write a
short paragraph about each.
a) Explain the distribution of the world’s terrestrial and
marine hotspots in Figure 3.
1
2
3
4
• Define hotspot
• Terrestrial hotspots - % land covered. Geographical location of
majority of hotspots. Examples. Biodiversity Threats
• Marine hotspots- types of ecosystem. Examples. Threats.
• Explanation – detailed locations mentioned. Explains reasons
for high biodiversity. Highlights range of ecological niches,
complex food chains, details of endemism and reasons for the
range of threats.
b) Evaluate the relative advantages and disadvantages of the
‘hotspot’ approach to biodiversity management (compared
with other strategies) (15)
1
2
3
4
• For hotspot approach
• Against hotspot approach – against protectionist approach
• Alterative mode of conservation
• conclusion