Question

Which graph correctly represents the species-area relationship on a logarithmic scale?

• A. Straight line with positive slope
• B. Straight line with negative slope
• C. Circular curve
• D. Horizontal line

Hint:

Normal species-area graph is curved, but log-log graph becomes a straight line.

Answer 1

The Correct Option is A

Concept: Species richness increases with increase in explored area. This relationship becomes linear when plotted on a logarithmic scale.

Step 1: Writing the species-area equation.
The relationship is represented by: \[ S = CA^Z \]

Step 2: Converting into logarithmic form.
Taking logarithm on both sides: \[ \log S = \log C + Z\log A \] This equation resembles: \[ y = mx + c \]

Step 3: Interpreting the graph.
Since the equation is linear in logarithmic form:

• The graph becomes a straight line.
• The slope of the line is positive because species richness increases with area.

Step 4: Choosing the correct option.
Hence, the correct graph is: \[ \text{Straight line with positive slope} \]