Question

The graph shows species area relationship. Answer the following
Write the situations as discovered by ecologists when the value of '$Z$' (slope of line) lies between
(i) 0.1 and 0.2
(ii) 0.6 and 1.2
What does '$Z$' stand for

Answer 1

(i) The value of Z lies in the range of 0.1 to 0.2, regardless of the taxonomic group or the region. Whether it is the plants in Britain, birds in California or molluscs in New York state value lies in the range 0.1-0.2.

(ii) if we analyse the species-area relationships among very large areas like the entire continents, we will find that the slope of the line to be much steeper (Z values in the range of 0.6 to 1.2). For example, for frugivorous (fruit-eating) birds and mammals in the tropical forests of different continents, the slope is found to be 1.15.

Z stands for the slope of the line (regression coefficient).