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Question #46079
The Question
A large biosphere reserve is severely fragmented, leaving the climax community of the core zone isolated like an 'island' within an intensive agricultural matrix. Over several decades, ecologists observe a permanent decline in the reserve's standing crop, despite absolute protection from human interference in the core. Which of the following biogeochemical mechanisms best explains this degradation?
Options
- A.
Loss of migratory fauna disrupts natural nutrient vectors, leading to landscape-level nutrient immobility and a decoupling of the mineralization cycle from biomass uptake.
- B.
Increased edge effect accelerates the rate of catabolism by decomposers, rapidly depleting the standing state and subsequently reducing the standing crop.
- C.
Fragmentation shifts the ecosystem's primary nutrient cycling from a sedimentary phase to a gaseous phase, causing rapid volatilization of essential minerals like phosphorus.
- D.
The isolated core zone experiences a complete cessation of primary succession, preventing pioneer species from replenishing the soil's reservoir pool.
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
Core_Area|Buffer_Zone|Transition_Zone|Alien_Species_Invasion_Impacts
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often view 'Nutrient Cycling' strictly as a localized, microscopic soil process (humification/mineralization by microbes) and fail to integrate 'Landscape Ecology'—specifically that macro-faunal migration acts as a crucial biogeochemical vector.
The common misconception is assuming that if a core zone is strictly protected from logging/hunting, its biomass (standing crop) will remain stable indefinitely, ignoring the open-system nature of nutrient fluxes and the necessity of biological corridors.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biodiversity and Conservation - Class 12 |
| Concept | Biosphere Reserves Architecture |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |