The graph formed by plotting species richness against area for a wide variety of taxa (angiosperm plants, birds , bats , fresh water fishes , etc) turns out to be a

Options

A. parabola
B. straight line
C. Rectangular hyperbola
D. Any of the above

Answer

To solve the question regarding the relationship between species richness and area, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Species Richness and Area**:
- Species richness refers to the number of different species present in a given area.
- The area refers to the size of the habitat being studied.

2. **Historical Context**:
- The relationship between species richness and area was notably studied by the German naturalist Alexander von Humboldt. He explored various ecosystems and documented his findings.

3. **Plotting the Graph**:
- When plotting species richness (S) on the y-axis against area (A) on the x-axis, the graph typically shows how biodiversity varies with the size of the area.

4. **Shape of the Graph**:
- According to Humboldt's findings, the graph of species richness against area forms a rectangular hyperbola. This indicates that as the area increases, species richness also increases, but not indefinitely.

5. **Mathematical Representation**:
- The relationship can be mathematically represented by the equation:
\[ S = CA^Z \]
where:
- \( S \) = species richness
- \( C \) = constant
- \( A \) = area
- \( Z \) = slope of the graph.

6. **Logarithmic Transformation**:
- When the data is transformed using logarithms, the relationship can be expressed as:
\[ \log S = \log C + Z \log A \]
This transformation results in a straight line on a log-log scale.

7. **Conclusion**:
- The overall conclusion is that the graph formed by plotting species richness against area for various taxa will exhibit a rectangular hyperbolic shape, indicating that while species richness increases with area, it does so at a diminishing rate.