Which of the following factors is NOT an abiotic factor affecting plant distribution?

Abiotic factors refer to the non-living components of an environment that influence the distribution and behavior of organisms, including plants. These factors encompass a range of physical and chemical aspects such as temperature, moisture, light, soil composition, and gases available in the environment.

In this context, competition with other plants is a biotic factor—not abiotic—because it involves interactions between living organisms. Biotic factors are associated with the presence and activities of living organisms, including competition for resources like light, space, and nutrients.

Soil pH influences the availability of nutrients to plants and, consequently, their growth and distribution. Oxygen levels are crucial for respiration processes in roots and can affect plant health and distribution in varying soil environments. Light availability directly impacts photosynthesis, influencing where certain plants can thrive based on their light requirements.

Thus, competition with other plants stands apart as a biotic interaction, while the other factors mentioned are all non-living variables that shape the environment in which plants grow.