What are the Nutrient Cycles?
Earth's amount of elements are limited to how much there is now since it is a closed system. The number of elements do not increase or decrease but are recycled through Earth in biological and geological cycles. The four main biogeochemical cycles illustrate movement of water, carbon, nitrogen, and phosphorus. They cycle through the biosphere, lithosphere, hydrosphere, and atmosphere over a long period of times, sometimes even millions of years.