Final answer:
In population biology, land is listed as an abiotic limiting factor of population size. Other examples include climate conditions and available nutrients. Food, mates, and predators are considered biotic factors.
Step-by-step explanation:
In the context of population biology, abiotic are non-living factors that can impact the size of a population. Examples of abiotic limiting factors include climate conditions (temperature, rainfall), geographical space (land), and available nutrients.
From your list (food, predators, land, mates), land is the main abiotic factor. Food and mates are typically categorized as biotic factors because they are living or once-living organisms. Predators also belong in the biotic category - they are living organisms that directly influence prey populations.
Learn more about abiotic limiting factors