IB Environmental systems and societies 2.3E Nitrogen Cycle Key Definitions

Ammonification (a type of decomposition) converts organic nitrogen (e.g., amino acids, urea) into ammonia or ammonium ions.

Decomposition is the breakdown of organic nitrogen in dead organisms and waste products into ammonium (NH₄⁺).

Denitrification is the conversion of nitrates (NO₃⁻) back into nitrogen gas (N₂), which is released into the atmosphere.

Eutrophication is a process where excess nutrients, primarily nitrates and phosphates, enter aquatic ecosystems, triggering a cascade of ecological changes.

A mutualistic nitrogen-fixing relationship is a symbiotic interaction between plants and nitrogen-fixing bacteria, where both organisms benefit.

Nitrification is the conversion of ammonia (NH₃) to nitrates (NO₃⁻).

The nitrogen cycle is a biogeochemical cycle through which nitrogen is transferred and transformed between the atmosphere, biosphere, hydrosphere, and lithosphere, ensuring its continued availability to living organisms.

Nitrogen fixation is the conversion of nitrogen gas (N₂) from the atmosphere into ammonia (NH₃).

A planetary boundary is a scientifically defined threshold beyond which human activities risk causing abrupt or irreversible environmental change.

The Haber process is an industrial method used to produce ammonia (NH₃) from atmospheric nitrogen (N₂) and hydrogen (H₂).

Transfers involve the movement of matter or energy from one place to another without changing its form.

Transformations involve a change in the chemical nature, state, or energy type of matter or energy.