How do forests conserve soil?

Answer 1

The tree's roots holds the soil and soaks up water to prevent soil erosion.

Actually, it's the action of "soaking up water" that will cause soil erosion, just like too much water will cause soil erosion. The real answer to this question is really about the litter that the trees create that minimizes--not prevents--soil erosion. Soil erosion is also prevented in treeless areas like in natural grasslands where the same thing happens: the roots and litter layed down by dead plant material conserves and minimizes soil erosion.

Answer 2

Forests help to conserve soil by reducing erosion through their root systems which help to bind the soil together. The leaf litter and organic matter that falls to the forest floor also help to improve soil structure and prevent erosion. The canopies of trees in forests intercept rainfall, reducing the impact of water on the soil and preventing soil compaction.

Answer 3

The roots help to bind the soil together, the leaves falling each Autumn cover the ground and the rotting leaves and fallen tree-trunks add nutrients back into the soil.