Question

Rahul was studying about the species richness in an area. He got a $Z$ value between $0.6-1.2$. From the given information, identify the type of area he was studying.

• A. State
• B. Continent
• C. Tropical rain forest
• D. Country

Answer 1

The correct option is B Continent

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 line 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 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.