Fungi play a crucial role in nutrient cycling, especially in the decomposition of organic matter. They break down dead plant and animal material, releasing nutrients such as nitrogen, phosphorus, and carbon back into the soil. This process helps to replenish essential nutrients in the ecosystem and support the growth of new plants. Fungi also form mutualistic relationships with plants, such as mycorrhizae, which assist in nutrient uptake by plants. Overall, fungi are key players in the nutrient cycling process, contributing to the balance and sustainability of ecosystems.