Biogeochemistry
Biogeochemistry studies how chemical elements and compounds move through and interact among organisms, rocks, soils, water, and the atmosphere.
Biogeochemical cycle: A pathway by which chemical elements circulate among organisms and environmental reservoirs. Cycles organize the movement of matter that biogeochemistry measures and explains.
Biogeochemical reservoir: A pool of an element stored in a defined part of Earth or its living systems. Reservoirs identify where an element is stored before or after a transfer.
Eutrophication: The enrichment of water with nutrients that promotes excessive biological production and can deplete oxygen. Nutrient transfers from land to water explain many eutrophication events.
Vladimir Vernadsky: A Russian-Ukrainian geochemist who developed the concept of the biosphere and emphasized life’s geological influence. His biosphere concept made organisms central to the movement of matter across Earth.
Earth system science: The study of interactions among Earth’s atmosphere, hydrosphere, geosphere, biosphere, and human systems. Biogeochemical cycles are central to understanding the coupled Earth system.
Carbon cycle: The movement of carbon among the atmosphere, oceans, land, rocks, and living things. Carbon transfers connect biological production, decomposition, ocean chemistry, and long-term burial.
Biogeochemical flux: The rate at which an element moves between reservoirs or across a system boundary. Fluxes quantify transfers such as carbon uptake, nutrient leaching, and gas exchange.
Ocean acidification: The decline in ocean pH caused mainly by seawater absorbing atmospheric carbon dioxide. Carbon exchange between air and ocean alters seawater chemistry and affects marine organisms.
G. Evelyn Hutchinson: An American ecologist whose work helped establish modern limnology and ecosystem ecology. His ecosystem approach connected ecological processes with nutrient cycling in lakes.
Permafrost carbon cycle: The storage and release of carbon in frozen soils as permafrost thaws and refreezes. Thaw can expose stored organic matter to decomposition, creating uncertain climate feedbacks.