biodiversity hotspots
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Biodiversity hotspots. What is a biodiversity hotspot ?. - PowerPoint PPT PresentationTRANSCRIPT
BIODIVERSITY HOTSPOTS
What is a biodiversity hotspot ?
A biodiversity hotspot is a geographic area containing at least 1,500 endemic plant species, but which has already lost at least 70% of species in their original state. The total area of hot spots is only 2.3% of the surface of the Earth. At present, areas 34 are hot spots. More than 50% of plant species and 42% of terrestrial vertebrate species live in these hot spots.
Where are they located ?As you can see there a lot of hot spots, more precisely 34. They are concentrated in the southern hemisphere of the planet
We will look at four hot spots among the 34 identified to understand what are the characteristics of these areas. 4 hot spots are: New Caledonia, Central America, Tropical Andes, the Mediterranean Basin
New Caledonia Tropical Andes
the Mediterranean Basin
Central America
Some statistics
Taxons Total number of species
described worldwideVascular plants 25000Land mammals 4596Birds 9950Reptiles 7900Amphibians 4780Freshwater fish 10000
Total number of described species in the world for 6 groups of beings living
Metropolitan FranceTaxon number
species% From total described species
% Of species endemic
Vascular plants 10507 4,2 0,58
Land mammals 166 3,6 0
Birds 539 5,41 1
Reptiles 40 0,5 0
Amphibians 32 0,66 3
Freshwater fish 94 0,94 9,5
Number of identified species and endemic in France 6 for these taxa
New Caledonia
Taxon number species
% From total described species
% Of species endemic
Vascular plants 3270 1,3 74,4
Land mammals 9 0,19 66,7
Birds 105 1,05 21,9
Reptiles 70 0,88 88,6
Amphibians 0 0 0
Freshwater fish 85 0,85 10,6
Central America
Taxon number species
% From total described species
% Of species endemic
Vascular plants 1700 6,8 17,3
Land mammals 440 9,57 15
Birds 1113 11,16 18,7
Reptiles 692 8,75 34,7
Amphibians 555 11,61 64,5
Freshwater fish 509 5,09 66,8
Andes Tropicales
Taxon number species
% From total described species
% Of species endemic
Vascular plants 30000 12 50
Land mammals 570 12,40 13,2
Birds 1724 17,29 33,6
Reptiles 692 8,75 34,7
Amphibians 555 11,61 64,5
Freshwater fish 509 8,09 66,8
Mediterranean BasinTaxon number
species% From total
described species
% Of species endemic
Vascular plants 22500 9 52
Land mammals 226 4,9 11,1
Birds 489 4,9 5,1
Reptiles 230 2,91 33,5
Amphibians 79 1,65 34,2
Freshwater fish 216
2,16 29,2
Why did we have to protect these areas ?
These areas have high biodiversity and high levels of endemism. It means that we encounter in these areas some species that is not found in other places. This can justify that the priority is to protect these areas.
ConclusionBiodiversity is not evenly distributed across Earth. Some areas provide an habitat on small areas a high proportion terrestrial biodiversity. These particularly sensitive areas are called hot spots.