1. and value of biodiversity?
Defining Biodiversity
What is the nature
and value of biodiversity?
Learning Objectives –
Describe the global distribution of biodiversity
Define the term ‘hotspot’
Describe the global distribution of hotspots

2. Think at different scales : latitudes; continents; countries
Biodiversity
Describe the pattern!
Think at different scales : latitudes; continents; countries

3. LATITUDES
The pattern is strongly correlated with latitude – highest levels usually in the tropics
There is a gradual decrease in higher latitudes
CONTINENTS
South America
Asia
Oceania – Australia is unusually high due to ‘endemism’
COUNTRIES
Mostly found in developing countries
Brazil is ranked 1st

4. According to levels of biodiversity Brazil comes out on top.
750 species of tree
400 types of bird
100 types of reptile
1500 species of flowering birds

6. MAP OF GLOBAL BIODIVERSITY
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

7. Marine hotspots are essentially coral reef areas in the tropics (contain 24% of world’s coral reefs yet cover 0.017% of oceans)
Terrestrial and marine hotspots are often adjacent to each other e.g. Cape Floristic Province, South Africa

8. Biodiversity
Such choropleth maps give an overview of biodiversity distribution by country but
this can hide the real picture
What’s this about? Is there a link to biodiversity?

9. Hotspots Def: An area containing a huge number of
species, a large % of which are endemic
Described as ‘the most remarkable places on Earth and the most threatened’
They (25 hotspots) cover <2% of the Earth’s surface yet contain 44% of the World’s plant species and 35% of the World’s animal species*
*Conservation International has recently updated this analysis
34 identified hotspot areas which are home to 50% of the World’s plants and 77% of the terrestrial vertebrates
Conservation Intnl has recently updated this analysis
34 identified hotspot areas which are home to 50% of the World’s plants and 77% of the terrestrial vertebrates

10. Level of threat to species
HOTSPOT CRITERIA…
1.) THE NUMBER OF SPECIES (SPECIES RICHNESS)
2.) THE NUMBER OF ENDEMIC SPECIES
3.) THE NUMBER OF SPECIES AT RISK
Species richness
Endemic richness
Level of threat to species
Biodiversity hotspot

11. ENVIRONMENTAL SCIENTIST
NORMAN MEYERS
ENVIRONMENTAL SCIENTIST
DEVISED HOTSPOT CONCEPT
AIMED TO IDENTIFY PRIORITY AREAS FOR BIODIVERSITY CONSERVATION

12. Hotspots

13. Continental Hotspots Large Island Hotspots Small Island Hotspots
4 CATEGORIES OF HOTSPOT
Continental Hotspots
Large Island Hotspots
Small Island Hotspots
Marine Hotspots
ATLANTIC FOREST
AUSTRALIA
MADAGASCAR
CORAL REEF

14. Hotspots The top 25 land-based hotspots are divided into 3 categories
Continental hotspots
(richest in terms of biodiversity)
2. Large island (or continental island) hotspots
(contain diverse & distinctive species inc
relict fauna extinct elsewhere)
Small island hotspots
(low in species no’s but high in proportion of
endemics so at great risk of being wiped out)

15. HOTSPOT: BIODIVERSITY PATTERNS
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

16. Alterations in ecosystem composition Pollution
Invasive species
Alterations in ecosystem composition
Pollution
Threats to Biodiversity
Climate Change
Over exploitation
Habitat loss and destruction

17. Hotspots at risk China Specific Hotspots:
Reasons for High Biodiversity:
Signature Species:
Threats:
Galapagos Islands
Reasons for High Biodiversity:
Signature Species:
Threats:
Madagascar
Reasons for High Biodiversity:
Signature Species:
Threats:

18. ADVANTAGES OF HOTSPOTS
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

19. DISADVANTAGES OF HOTSPOTS
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.

20. TASK: SHOULD THE ARTIC BE A HOTPSOT?
PRODUCE AN ARGUMENT IN FAVOUR OF THE ARTIC BE MADE A HOTSPOT.
CONSIDER ITS IMPORTANCE AND WHAT THREATENS IT.