Why is the soil in the rain forest so poor?

The soil in rainforests is often poor due to its rapid decomposition and nutrient cycling. While the abundant rainfall supports lush vegetation, it also leaches essential nutrients from the soil. Additionally, the dense canopy prevents sunlight from reaching the forest floor, limiting the growth of underbrush that could contribute organic matter to the soil. As a result, the nutrient-rich top layer is quickly depleted, leaving the soil less fertile over time.