# What does log scale tells about the species richness as normal curve turns to be rectangular hyperbola ! Then what is the use of representing that hyperbola into log scale ?

The species area graph is a relationship between area of a habitat and the number of species. On logarithm scale (Log-Log area), the relationship is given by straight line. This according to Alexander Von Humboldt tells us that biodiversity increases with increase in explored area and this relationship can be given by:

log S = log C + Z log A

Where,
S = Species richness
A = Area
Z = Slope of the line (regression co-efficient)
C = Y-intercept

The relation between species richness and area for many organisms like angiosperms, birds, bats, fresh water fishes is rectangular parabola. This also tells us species richness increases with increase in area but on arithmetic scale or area . Regardless of the curve shape, the curve follows the following function:

S = cAz

S- number of species

A - Habitat area

z - Slope of the curve

c - constant which depends on the unit of area used for measurement