Problem 6 - Biology: The Dynamic Science

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.

Step-by-Step Solution

Answer

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

Step 1: Understanding the Concepts

Firstly, the concepts of species richness, disturbances, and their relationship must be understood. Species richness indicates the number of different species present in a particular environment, and it is influenced by various factors including disturbances. Disturbances are events that change environmental conditions and cause substantial changes in the organisms present.

Step 2: Analyzing the Options

Now, moving on to the options, option (a) suggests that very frequent and severe disturbances might result in maximum species richness. However, very severe disturbances could lead to mass extinction and thus, reduce species richness. Option (b) suggests that frequent but moderate disturbances lead to highest species richness. Frequent moderate disturbances might allow recovery and lead to a balance. Option (c) suggests that rarity and severity lead to maximum species richness. However, similar to option (a), severe disturbances, even if rare, can lead to mass extinction. Option (d) suggests intermediate frequency and moderate disturbances. Intermediate frequency allows for both survival and adaptation, while moderate intensity prevents mass extinction. Option (e) implies that very rare and mild disturbances lead to maximum species richness. However, this might lead to competition and dominance by certain species, reducing species richness.

Step 3: Choosing the Correct Option

Based on the analysis of options, it can be concluded that species richness might be highest in communities where disturbances are of 'Intermediate Frequency and Moderate Intensity'. This allows for survival, recovery, and adaptation, maintaining a high level of species richness.