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Question #46655
The Question
During the summer months in a high-latitude peat bog ecosystem, the photoperiod is exceptionally long, providing abundant Photosynthetically Active Radiation (PAR). However, the Net Primary Productivity (NPP) remains severely restricted. Based on the principles of decomposition and nutrient cycling, which of the following represents the primary ecological bottleneck?
Options
- A.
Anaerobic conditions and low temperatures inhibit microbial catabolism, leading to a rapid depletion of organic matter and a lack of substrate for mineralization.
- B.
Low temperatures and anaerobiosis suppress microbial enzymatic activity, halting mineralization and locking essential inorganic nutrients within the accumulated detritus.
- C.
The detritus is primarily rich in nitrogen and water-soluble sugars, which accelerates humification but completely prevents the release of inorganic nutrients.
- D.
High soil moisture promotes excessive leaching of water-soluble inorganic nutrients into the lower soil horizons, making them permanently unavailable to producers.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Stratification Efficiency|Alien Species Invasion Impacts|Lantana camara
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often assume that light (PAR) is the sole determinant of Net Primary Productivity (NPP) during summer.
The trap lies in failing to connect the climatic inhibition of decomposition (low temperature and anaerobiosis) to the cessation of 'mineralization'.
This creates a nutrient bottleneck where minerals remain locked in detritus, proving that NPP is heavily dependent on the soil-to-plant nutrient flux, not just photosynthetic light reactions.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Ecosystem - Class 12 |
| Concept | Stratification Efficiency |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |