The term “biogeochemical cycles”
is used in order to describe the transfer and transformation of matter and
energy between the biosphere and the other active reservoirs of Earth namely
the atmosphere, hydrosphere, and lithosphere.
During the functioning of a
biogeochemical cycle, a series of molecular species which are essential for
supporting life on the planet, also referred to as nutrients, are being
constantly transported and chemically transformed. The main
chemical elements making up the basic nutrients circulating within a
specific biogeochemical cycle and which are involved in the structuring of
complex bio-polymers (e.g. proteins, DNA, RNA, etc.) are C, N, S, P, and O.
A biogeochemical cycle is
activated via coupling of the biosphere to nutrient fluxes supplied by specific
sites or active centers on Earth (e.g. volcanoes and hydrothermal fields). Such
sites/centers act as a constant source of matter (e.g. volatile chemical
species) and/ or energy on the Earth surface, either on a regional or a global
scale, which can be used by different living forms.
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