落ち葉 (Foliage) refers to the leaves that fall from trees, especially during autumn. This natural process occurs as trees prepare for winter, conserving energy and resources. The vibrant colors of fallen leaves, such as red, orange, and yellow, are due to the breakdown of chlorophyll, revealing other pigments. Fallen leaves play a crucial role in the ecosystem. They decompose and enrich the soil with nutrients, supporting plant growth. Additionally, they provide habitat and food for various organisms, including insects and fungi, contributing to the overall health of the forest ecosystem.