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Question #46031

Difficulty: 8/10 | 🟢 Free

The Question

Read the following statements regarding ecological succession and the quantification of standing crop. Which of the following statements is INCORRECT?

Options

  • A.

    Both hydrarch and xerarch successions progress towards a mesic environment, culminating in a climax community that supports the maximum standing crop.

  • B.

    During the progression of seral stages, the ecosystem's total biomass continuously increases, but the Net Primary Productivity (NPP) eventually declines as the community reaches climax.

  • C.

    To sustain its maximum standing crop, the climax community maintains a Gross Production to Community Respiration (P/R) ratio significantly greater than 1.

  • D.

    The transition from pioneer to climax stages involves facilitation, where early species modify the substrate, increasing the ecosystem's capacity to support a larger standing crop.

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

Decomposition Rate Modifiers|Humification|Mineralization

Why This Question Is Tricky

Common Mistakes

Conceptual Pivot: Differentiating between 'Standing Crop' (a static measure of accumulated biomass) and 'Productivity' (a rate).

Students often fall for the misconception that a climax forest, having the largest standing crop, must also have the highest net productivity and a P/R ratio > 1.

They fail to account for the massive respiratory burden of the climax biomass, which brings the P/R ratio down to 1, establishing the steady-state equilibrium.

Quick Facts About This Question

Question Information

SubjectBiology
ChapterEcosystem - Class 12
ConceptStanding Crop quantification
Difficulty8
Cognitive Load5
Target Solve Time120 sec
AccessFree