1. Biological Hot Spots
Class 5
Presentation 1

2. Useful web site
Visit Conservation International’s web site for details on each of the 25 biodiversity hot spots in the world.

3. Definition High amount of endemic species
Must have 1500 endemic plant spp
High threat from human activity
Must have lost 70% of primary vegetation
First proposed by British ecologist Norman Myers in 1988
Hot spot area covers 2% of Earth

4. Ideas about endemic spp
Organisms become endemic:
Due to stranding or become relics
Dispersal then extinction on mainland
Dispersal or vicariant then speciation
Vicariant spp = due to chance splitting and isolation (e.g. new barrier forms)

5. Ideas about endemic spp
Taxonomic patterns:
Marine mammals, bats common, others not
Birds: excellent dispersal, high endemics
Butterflies: excellent dispersal, low endemics
Other insects high endemic, disharmonic diversity
Lizards (can swim) high endemics

6. Purpose Help mobilize action
Help prioritize conservation effort given limited resources

7. Hot spot locations Most on continents (16 of 25)
However, based on size,islands disproportionately represented (9)
E.g. Caribbean, Madagascar, Philippines
All in climatically benign regions, and somehow isolated

8. Islands are special Not as spp rich as continents per unit area
Size matters, smaller = less spp!
However high level of unique spp found no where else e.g. all 105 land snails on Easter Island found no where else on this planet! 68% of plants on St Helena found no where else.

9. Islands are special Dispersal affected by adaptations of taxa
Fresh water fish lowest dispersal (approx 5km)
Large mammals 50km
Rodents and reptiles 1100 km
Birds 3600 km (& butterflies)
Animals able to overcome distance barrier and colonize = rapid and prolific speciation (sweepstake dispersal)
Missing taxa = loss/absence of other taxa due to broken food webs, lack of intraspecific interactions (foundation spp missing)

10. Reason for islands
Oceanic Islands (never connected to mainland, part of tectonic plate)
Great distance and deep ocean limit immigration
Some taxa missing (mammals and amphibians)
Evolution Immigration
Fast evolution

11. Continental shelf islands
Less remote from continent
Can be reached by animals from continent
Immigration  Evolution
Evolution faster than on continent
Have indigenous mammals and amphibians
Geology varied (different productivity, habitat)

12. Sample of some biological hot spots

13. Madagascar & Islands
Broke away 160 million yrs ago from super continent Gondwanaland
10% original veg remains (59k ha)
11k ha protected
46 spp extinct
Of 12k plants, 9k endemic
Conservation International

14. Caribbean Floristic Region
Dry evergreen bushes with grassland
12% remains
12k plant spp
57k plant spp endemic
99 threatened spp
32 endangered
Conservation International

15. Other island hot spots Sundaland (Malay peninsula, Sumatra, Borneo)
Philippines
New Zealand
Polynesia and Micronesia
New Caledonia (smallest of hot spots)
Wallacea (Moluccas, central islands of Indonesia)
Western Ghats and Sri Lanka

16. Central Chile Isolated between Andes and Pacific 25% remains
3.4k plant spp
1.6k endemic
8 threatened spp
Conservation International

17. Cape Floristic Region Evergreen fire dependent shrubland 30% remains
8.2k plant spp
5.6k plant spp endemic
15 threatened spp
2 endangered
Conservation International

18. Caucasus Mountains, desert, grassland 10% remains 6.3k plant spp
1.6k plant spp endemic
10 threatened spp
3 endangered
Conservation International

19. Questions