In the context of factors limiting population growth, what primarily determines the carrying capacity (K) of an ecosystem for a given species?

• A. The total number of different species (species richness) present in the ecosystem
• B. The maximum reproductive rate of the species under ideal, unlimited-resource conditions
• C. The availability of limiting resources and environmental conditions (e.g., food, water, space, and suitable habitat) that constrain population size
• D. The age of the ecosystem and how long the species has been present there

Answer: (C)

Verified step by step guidance

1. Understand that carrying capacity (K) refers to the maximum population size of a species that an environment can sustain indefinitely without being degraded.
2. Recognize that carrying capacity is not determined by species richness (the number of different species) because it focuses on the limits for a single species' population size.
3. Know that the maximum reproductive rate under ideal conditions describes potential growth but does not set the limit on population size in a real environment.
4. Identify that carrying capacity is primarily influenced by the availability of limiting resources such as food, water, space, and suitable habitat, as well as environmental conditions that restrict population growth.
5. Conclude that factors like the age of the ecosystem or how long the species has been present do not directly determine carrying capacity, but rather the resources and conditions that support the species do.