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Question #46676
The Question
During primary succession on a newly formed bare rock, ecologists observe that the ecosystem is permanently arrested at the pioneer lichen and moss stage. Soil analysis reveals that while detritus is continuously added, the developing soil lacks water-holding capacity and a stable nutrient reservoir, causing inorganic nutrients to be rapidly lost to leaching. Which of the following kinetic imbalances in the decomposition process best explains this arrested seral progression?
Options
- A.
The rate of humification drastically exceeds mineralization, causing an excessive buildup of colloidal humus that inhibits root penetration.
- B.
The rate of mineralization drastically outpaces humification, preventing the accumulation of a colloidal nutrient reservoir.
- C.
The rate of fragmentation is completely inhibited, preventing the release of extracellular enzymes by bacterial and fungal decomposers.
- D.
The rate of catabolism is significantly slower than leaching, leading to the accumulation of undecomposed raw detritus.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Aquatic Ecosystem|Phytoplankton|Detritus Food Chain Dominance
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often view 'Mineralization' as a strictly positive process because it releases usable inorganic nutrients for plants.
The trap lies in failing to recognize the ecological necessity of 'Humification'.
Without the slow-degrading colloidal reservoir of humus, rapid mineralization in early succession leads to immediate nutrient leaching, preventing the soil development required for seral facilitation.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Ecosystem - Class 12 |
| Concept | Nutrient Cycling Reservoirs |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |