The cycling of matter and energy

In the biosphere matter is never lost; it circulates continuously, driven by solar energy. In the geological cycle abiotic factors act: rocks weather, are carried to the sea and form sediments, then tectonic movements raise them to land again; this takes tens or hundreds of thousands of years and involves all elements of the Earth’s crust. In the biological cycle only biogenic elements (C, H, O, N, P, S and others) take part and it is fast – years or decades: producers build organic matter from inorganic substances, consumers eat it, and decomposers break detritus down again into mineral substances. The two cycles are linked: some elements leave the biological cycle and enter the geological one as sediment, coal or oil, while elements of the geological cycle are taken up by living organisms. Together they form the biogeochemical cycle of elements, the basis of the stability of the biosphere.