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Question #46096
The Question
In a developing terrestrial ecosystem, the progression towards a stable climax community is unexpectedly arrested, resulting in a sub-climax state with stunted biomass accumulation. Soil analysis reveals a massive build-up of undecomposed organic matter. Based on the principles of ecosystem function, which of the following best explains this ecological stagnation?
Options
- A.
The detritus is predominantly rich in nitrogen and water-soluble sugars, causing rapid humification but delayed mineralization.
- B.
High soil temperature and aeration have accelerated nutrient immobilization, permanently locking inorganic nutrients in the microbial biomass.
- C.
The ecosystem's Gross Primary Productivity (GPP) has become exactly equal to its respiratory losses (R), a hallmark of arrested seral stages.
- D.
Detritus rich in lignin and chitin under anaerobic conditions has inhibited mineralization, leading to nutrient immobility that restricts the NPP required for climax transition.
Check Your Answer
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
Keystone Species|Ecosystem Stability|Extinction
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that 'succession leads to climax' without connecting it to the biogeochemical prerequisites (mineralization and NPP).
The trap in Option C tests the misconception regarding GPP and Respiration ratios; GPP > R is needed during seral stages to accumulate biomass, while GPP = R signifies a stable climax.
Option D correctly links NCERT decomposition rate modifiers (lignin/chitin/anaerobiosis) to nutrient immobility, explaining the stalled succession.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biodiversity and Conservation - Class 12 |
| Concept | Convention on Biological Diversity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |