NUTRIENT CYCLE

nutrient cycle: translation

the movement of nutrients in the ecosystem between the three major stores of the soil, biomass and litter. Nutrients are taken up from the soil by plant roots to produce biomass. In its simplest form this then dies and falls to the ground where it becomes litter. The litter then decomposes and is returned to the soil where the cycle begins again. Complications exist with movement of nutrients within the biomass e.g. when plants are eaten and then herbivores in their turn. There are also inputs and outputs depending on the scale of ecosystem being considered. Nutrients may enter through weathering or migrating organisms. They may be lost by leaching. The proportion of nutrients held in each store and in flow at any one time will be determined by the prevailing conditions of each ecosystem.