Which of the following factors does not affect the distribution of pasture grasses?

The factor that does not affect the distribution of pasture grasses is "pests". While pests can certainly impact the health and growth of individual plants, they are not a significant factor in determining the distribution of pasture grasses as a whole. On the other hand, wind, temperature, and soil are all important factors that can affect the distribution of pasture grasses. For example, some species of grass may be better adapted to grow in hot, arid climates, while others may thrive in cooler, wetter environments. Similarly, different types of soil may be more or less suitable for supporting certain species of grass, depending on their nutrient requirements and other factors. Wind can also play a role in determining where pasture grasses are found, as it can impact the dispersal of seeds and the growth patterns of individual plants. Therefore, the most appropriate option for the given question is "pests".