Biogeokeemilised

Biogeokeemilised (biogeochemical) processes describe the interactions among living organisms, minerals and rocks, and chemical reactions that govern the movement and transformation of elements within the Earth's systems. The term covers how life alters chemical forms and fluxes of elements such as carbon, nitrogen, sulfur and phosphorus, and how abiotic conditions shape biological activity.

Key mechanisms include photosynthesis and respiration, decomposition, mineral weathering, dissolution and precipitation of minerals, and redox reactions mediated by microbes. Microorganisms play a central role by transforming nutrients, mediating exchange between soils and water, and driving cycles at interfaces such as the rhizosphere and sediments.

Major biogeochemical cycles include the carbon cycle, nitrogen cycle, sulfur cycle and phosphorus cycle. Each cycle involves production, consumption, transformation, and storage of elements across the atmosphere, hydrosphere, biosphere and lithosphere. Human activities, such as fossil fuel combustion, agriculture and mining, perturb these cycles, with implications for climate, soil fertility, water quality and ecosystem health.

Biogeochemistry is the scientific discipline that studies these processes, often using isotopic tracers, measurements of element pools, and computer models to understand fluxes and feedbacks on local to global scales. The concept originated in part with early 20th-century geochemistry and the work of Vladimir Vernadsky, who described the biosphere as a chemical system.