Introduction

Metapopulation theory is central to modern conservation biology, especially in fragmented landscapes. Understanding how local extinctions, patch size, connectivity, and habitat quality interact is vital for designing effective conservation strategies. Here, we evaluate a set of statements about metapopulation dynamics and habitat conservation to identify which are correct and best supported by ecological research.

Evaluating the Statements

Statement A

“The sizes of suitable patches are important because demographic stochasticity can lead to extinction, especially in organisms with low reproductive output.”

• Correct.
  Larger patches support bigger populations, which are less vulnerable to random demographic events (demographic stochasticity) that can cause extinction, especially in species with low reproductive rates. Small patches, by contrast, are at greater risk.

Statement B

“In the incidence function model (IFM), the extinction risk of local populations increases with increasing habitat patch area, and the colonization probability is a function of patch isolation from existing local populations.”

• Incorrect.
  In the IFM, extinction risk actually decreases as patch area increases because larger patches support larger, more stable populations. Colonization probability does depend on patch isolation, but the first part of this statement is not accurate.

Statement C

“From the conservation perspective, large numbers of suitable patches are not sufficient if distances are too large, preventing recolonization and the rescue effect.”

• Correct.
  Even if many habitat patches exist, if they are too isolated, dispersal between them is limited. This prevents recolonization of empty patches and reduces the rescue effect, increasing metapopulation extinction risk.

Statement D

“To minimize extinction risk there should be as low a variance in local patch quality as possible, to allow for synchronous dynamics.”

• Incorrect.
  Low variance in patch quality can actually increase extinction risk if all patches experience poor conditions simultaneously (synchronous dynamics). Asynchronous dynamics—where some patches do well while others do poorly—help buffer the metapopulation against extinction.

Best Combination of Correct Statements

Based on this analysis, the correct combination is:

(1) A and C

• Patch size is crucial for reducing extinction risk due to demographic stochasticity.

• Connectivity and the ability for recolonization are essential; isolated patches cannot benefit from rescue effects.

Conclusion

The most accurate and ecologically supported statements about metapopulation dynamics and habitat conservation are:

• A: The importance of patch size in reducing demographic extinction risk.

• C: The necessity of patch connectivity for recolonization and maintaining metapopulation persistence.

Correct answer:
(1) A and C