​Given below are a set of statements about metapopulation dynamics and habitat conservation:

A. The sizes of suitable patches are important because demographic stochasticity can lead to extinction, especially in organisms with low reproductive output.
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.
C. From the conservation perspective, large numbers of suitable patches are not sufficient if distances are too large, preventing recolonization and the rescue effect.
D. To minimize extinction risk, there should be as low a variance in local patch quality as possible, to allow for synchronous dynamics.

Which one of the following options represents the combination of all correct statements?

Correct option is A

• Statement A is correct: Suitable patch sizes are important for reducing the risk of extinction, especially for species with low reproductive output. Larger patches tend to have more stable populations that are less vulnerable to demographic stochasticity.

• Statement B is incorrect: In the incidence function model (IFM), extinction risk tends to decrease with larger habitat patch areas because larger patches can support more individuals, reducing the likelihood of extinction. The colonization probability, however, does depend on patch isolation.

• Statement C is correct: The proximity of habitat patches is crucial for recolonization and the rescue effect. If patches are too distant, it prevents populations from reconnecting and increases extinction risk.

• Statement D is incorrect: To minimize extinction risk, it is not always necessary to have low variance in patch quality. Some degree of variability in habitat quality can be beneficial for sustaining diverse populations.

Information Booster:

1. Demographic stochasticity refers to the random variations in population dynamics due to birth and death events, and it is more significant in small populations.
2. Incidence function model (IFM) suggests that larger patches tend to have lower extinction risks, contrary to what Statement B claims.
3. Rescue effect occurs when immigration from nearby populations helps to bolster the declining population in isolated patches, which is prevented if patches are too far apart.
4. Patch quality variance can be advantageous in creating diverse habitat conditions, but extremely low variance may limit ecological complexity.
5. Metapopulation dynamics highlight the importance of habitat connectivity and quality for species persistence across fragmented landscapes.