Which scenario would likely decrease carrying capacity for a species in a region?

Which scenario would likely decrease carrying capacity for a species in a region?

• A. A predator is introduced that reduces prey numbers without changing resource levels.
• B. Drought reduces water availability.
• C. A new shelter is built that improves microhabitats.
• D. Habitat restoration increases food resources.

Answer: (B)

Carrying capacity is the largest population an environment can sustain over time given the available resources and conditions. When drought cuts water availability, a key resource for many organisms becomes scarce. That reduction lowers the environment’s ability to support as many individuals, so the carrying capacity decreases. The other scenarios don’t reduce resources in the same way: introducing a predator lowers prey numbers but doesn’t change the amount of resources the area can supply, so the capacity to support the population remains the same; adding shelter or restoring habitat tends to improve conditions and resources, which can maintain or increase carrying capacity.

Carrying capacity is the largest population an environment can sustain over time given the available resources and conditions. When drought cuts water availability, a key resource for many organisms becomes scarce. That reduction lowers the environment’s ability to support as many individuals, so the carrying capacity decreases.

The other scenarios don’t reduce resources in the same way: introducing a predator lowers prey numbers but doesn’t change the amount of resources the area can supply, so the capacity to support the population remains the same; adding shelter or restoring habitat tends to improve conditions and resources, which can maintain or increase carrying capacity.