Why are mulches important in erosion control?

Mulches play a vital role in erosion control primarily because they protect soil against erosion from rainfall. When raindrops hit bare soil, they can dislodge soil particles, leading to surface erosion. By covering the soil with mulch, the impact of rainfall is softened, which minimizes the displacement of soil particles. Additionally, mulches help to retain moisture in the soil, which supports plant growth that can further stabilize the soil and reduce erosion risk.

The other options, while they may relate to various aspects of soil and plant interaction, do not directly address the primary function of mulches in erosion control as effectively as the correct response does.