Tree Shed Their - Leaves In

As leaves decompose, they create leaf litter or "duff." This layer acts as a blanket for the soil, insulating the roots of the trees from extreme cold. As bacteria, fungi, and invertebrates break the leaves down, they return vital nutrients—particularly nitrogen and phosphorus—back into the soil. In the spring, the tree will use these recycled nutrients to fuel the growth of new leaves, completing the cycle.