Question

Write about species-area relationship.

Answer 1

Alexander Van Humboldt gave the concept of Specie-Area relationship based upon his observation in South American jungle studies. He observed that within a region the richness of specie increases with the increase in explored area, but only up to a limit. The richness can be explained by this logarithmic mathematical equation :

Log S = LogC + ZLogA

where,

S = Specie richness

A= Area explored

C = Y-intercept

Z= Slope of line i.e., Regression coefficient.

The graph plotted between specie richness and area of a wide variety of taxa gives a rectangular hyperbola according to the mathematical equation ( S=CA${}^Z$ ).

Ecologist describes the value of Z is in range of 0.1 and 0.2 irrespective of the specie or region evaluated. But, if we find the specie - area relationship for a very large area like that of a continent then the value of Z is observed to be between 0.6 and 1.2 thus the graph in such situation comes out to be much steeper.