Where is the world’s biological diversity?
1) Tropics
a. rain forest
3.1 Tropical rain forests are found predominantly in wet equatorial regions.
Where is the world’s biological diversity?
b. ocean -28 of 35 animal phyla
(1) coral reefs
(2) deep sea
c. large tropical lakes
2) Temperate forests and shrublands in southwestern Australia, Cape Region
of South Africa, California, central Chile, and Mediterranean Basin
3.2 Coral reefs in tropical waters
4 Factors affecting species richness
-there are concentrations of species in particular areas and a rough
correspondence in distribution of species richness between different
groups of organisms
In North America, large-scale patterns of species richness are highly
correlated for amphibians, birds, butterflies, mammals, reptiles, land
snails, vascular plants, and tiger beetles. Similar pattern in regions of
South America for birds, amphibians, plants, and mammals.
In marine ecosystems, cone snails are an indicator of marine biodiversity
Fig. 3.4
Figure 3.3 Species richness for vertebrates is greatest in tropical regions with abundant rainfall
Figure 3.4 Cone snails are an indicator group for marine biodiversity
What pattern do you see in this table?
Why are there so many species in the Tropics?
How many species exist worldwide?
-numbers obtained from diversity surveys of entire regions
ex. our Flora of PINS, Flora of North America
-1.5 million species described worldwide with estimates of 5-10 million
total
-this inflated estimate from that which scientists have described (1.5 million) is
supported by the following:
3.5 Approximately 1.5 million species have been identified and described by scientists
Figure 3.7 (A) Access to the diverse world of insects in the rain forest canopy (B) Research carried
out in the tree canopy using a dirigible to lower a platform so scientist can work from it.
How many species exist worldwide?
4) rainforest reserve between Laos and Vietnam yielded three new large
mammals (giant muntjac (striped, red-rumped rabbit), the Vu Quang Ox,
and slow running deer). In Laos, a rodent thought to be extinct for 11
million years was re-discovered in a food market. Fig. 3.7 New order of
insects from Africa commonly called gladiator insects..
5) new communities around hydrothermal vents and oil plumes on the deep sea
floor - Box 3.1.
6) Many new bacterial and fungal species-Box 3.2
Figure 3.7 Researchers first found Laonastes aenigmamus being sold in Laotian food markets
Hydrothermal vent community dominated by tube worms