Question

Read the following related to the value of Z and identify the correct option.
A. Fruit eating birds in the tropical forests - 1.15
B. Plants in Britain - 0.1 to 0.2
C. Asian continent - 1.2 to 1.6

• A. Only A
• B. Only B
• C. A and B
• D. A and C

Answer 1

The correct option is C A and B

Alexander von Humboldt, a German naturalist and geographer, proposed the species - area relationships during his extensive explorations in the South American jungles. He observed that, within a region, species richness increased with increasing explored area, but upto a certain limit.
The relationship between species richness and area can be given by the equation
$S=C{A}^z$
where S - Species richness
Z - Slope of line (regression coefficient)
C - Y-intercept
A - Area

Ecologists have found out that the value of the Z ranges between 0.1 and 0.2 irrespective of the taxonomic group or the region. For example, the plants in Britain, birds in California, molluscs in New York state, etc.
As the area increases, such as in case of entire continents, the slope of the line is much steeper and the Z value ranges between 0.6 to 1.2.
For frugivorous (fruit-eating) birds and mammals in the tropical forests, the slope is found to be 1.15.