Question

Species richness is often highest in communities where disturbances are: a. very frequent and severe. b. very frequent and of moderate intensity. c. very rare and severe. d. of intermediate frequency and moderate intensity. e. very rare and mild.

Short answer

The correct answer is d. Species richness is often highest in communities where disturbances are of intermediate frequency and moderate intensity.

Step-by-step solution

Understanding the Concept of Disturbance

Species richness in a community refers to the number of different species in a defined area. Disturbance refers to a significant change that occurs in an ecosystem, either through natural events like storms or fire, or through human activities such as deforestation.

Understanding the Relationship between Disturbance and Species Richness

In nature, it's observed that the biodiversity of an ecosystem often follows the Intermediate Disturbance Hypothesis. This theory suggests that species richness is highest at an intermediate level of disturbance.

Understanding the Options

Based on the Intermediate Disturbance Hypothesis, we can analyze the given options. Options a and c suggest extremes of very frequent/severe, and very rare/severe disturbance. According to the theory, these extreme disturbances are less likely to result in high biodiversity. Option b and e suggest mild or moderate intensity disturbances, but with very frequent or very rare occurrences, which still doesn't fit the theory. Only option d suggests an intermediate frequency and moderate intensity, which aligns with the theory.

Selecting the Right Answer

Based on the foregoing understanding of the relationship between species richness and disturbance, the most accurate statement is the one that aligns with the Intermediate Disturbance Hypothesis. That is option d: 'of intermediate frequency and moderate intensity'.