Trees are essential components of nutrient cycling in forest ecosystems. Through the process of leaf fall and decomposition, trees return vital nutrients like nitrogen, phosphorus, and potassium back to the soil surface, creating a rich layer of organic matter that supports continued forest growth.
The seasonal leaf fall is a critical phase in the nutrient cycle. As temperatures drop and daylight decreases, trees begin to withdraw nutrients from their leaves and shed them. These fallen leaves accumulate on the forest floor, forming a layer of organic matter rich in nitrogen, phosphorus, and potassium.
The decomposition process is driven by soil microorganisms including bacteria and fungi. These decomposers break down the complex organic compounds in fallen leaves, releasing essential nutrients. Nitrogen from proteins, phosphorus from nucleic acids, and potassium from cellular structures are gradually released into the soil solution.
The decomposed nutrients create a concentration gradient in the soil, with the highest levels in the surface layer. This nutrient-rich zone, typically in the top 5 to 15 centimeters, becomes the primary feeding area for plant roots. The enriched surface soil supports vigorous plant growth and maintains the forest's productivity cycle.