Biogeography• Large scale patterns of global diversity• Geographic gradients• Environmental gradients• Long term distributions: Evolutionary processes

Species richness

Boreal forests of Canada

Elevational gradient in Arizona

Patterns of Species richness

• Latitudinal patterns• Temperate zone

Theories

Theories

Patterns of speciation

Circumpolar

Extinctions

• Continental differences

• Alps created a barrier• North America vs

China, connections to tropics.

• SE US and Europe separated from tropical flora

Continental patterns

Endemism and isolation

Transition zones

C3 and C4 plants

Endemism and Isolation