Biodiversity and Conservation: Patterns of Diversity and the Island Theory

Six distinct biogeographic regions

Neoarctic, Neotropical, Afrotropical, Palearctic, Indomalayan, and Australia

Latitude and area

Two factors that affect species diversity

Species richness

Number of species; especially great in the tropics and declines along an equitorial-pole gradient

Species diversity

Number of species and their relative abundances

Species area curve

A graphical relationship in which increases in area (A) are associated with increases in species richness (S); quantifies the idea that a larger geographic area has more species; S = cA^z

Island equilibrium model

Species richness depends on island size and distance from the mainland; A greater size or a smaller distance would increase species richness

Types of islands

Includes mountain tops, bogs, ponds, dunes, and/or individual hosts for a parasite; Any habitat isolated from similar habitat by an uncrossable habitat/region is an island