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Question #46647
The Question
An ecotone acting as a critical transition zone between a dense forest and a grassland undergoes severe habitat fragmentation. This leads to the localized extinction of specific 'edge-specialist' shrubs and, subsequently, their obligate insect pollinators. Based on Paul Ehrlich’s Rivet Popper Hypothesis and the principles of biodiversity loss, which of the following is the most accurate ecological prognosis?
Options
- A.
The extinction of these edge-specialists represents the loss of 'rivets on the seats', causing an immediate and total collapse of the adjacent core forest ecosystem.
- B.
The co-extinction of the shrubs and pollinators removes the ecotone's structural complexity, destroying its buffering capacity and destabilizing the regional trophic network, even if core ecosystems are initially unaffected.
- C.
According to the Species-Area relationship, the reduced ecotone area will proportionally decrease the Z-value (slope of the line), thereby accelerating the extinction of core forest species.
- D.
The loss of these species will trigger an immediate secondary succession, rapidly restoring the ecotone's original species composition and trophic stability.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Optimal Foraging Theory|Hydrarch vs Xerarch Convergence|Ecological Succession Climax
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize the Rivet Popper Hypothesis (airplane analogy) without applying it to spatial ecology (ecotones).
The primary trap is Option C, which preys on the misunderstanding of the mathematical constant 'Z' in the Species-Area relationship.
Students must synthesize that co-extinction in a transition zone dismantles the 'buffering capacity' of the landscape, acting as the loss of a 'key rivet' for regional trophic stability, rather than causing an immediate collapse of the core ecosystems.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Organisms and Populations - Class 12 |
| Concept | Optimal Foraging Theory |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |