biogeochemistry

Biogeochemistry is an interdisciplinary field that studies the chemical, physical, geological, and biological processes that govern the distribution and transformation of elements within the Earth system. It examines how living organisms influence chemical reactions and cycles, and how abiotic conditions such as climate, rocks, water, and soils shape biological activity. The field integrates geology, chemistry, ecology, and soil science to trace element fates across air, water, soil, and biota.

Central to biogeochemistry are the major cycles of carbon, nitrogen, phosphorus, sulfur, oxygen, and hydrogen, along with trace metals. Key processes include mineralization and decomposition of organic matter, fixation and assimilation by organisms, and redox-driven transformations such as nitrification and denitrification. Geochemical processes such as weathering, dissolution, precipitation, sedimentation, and groundwater flow interact with biology to regulate element availability and fluxes from local to global scales.

Methods include stable isotope analysis, tracers, mineralogical and chemical measurements, field observations, and models to quantify fluxes and pathways. Biogeochemistry operates on time scales from seasonal to geological, and on spatial scales from microhabitats to oceans and continents. The field owes much to early geochemists and to Vladimir Vernadsky, who described the biosphere as a geological force shaping the Earth.

Applications include climate-carbon feedbacks, nutrient management in soils and waters, pollution fate and remediation, and ecosystem stewardship. By linking biology with geology and chemistry, biogeochemistry provides a framework for predicting how human activities alter element cycles and ecosystem services.