Nutrients and their cycles

Macronutrients

Nutrients needed in large amounts (e.g., carbon, nitrogen, phosphorus, potassium, sulfur).

Reservoirs

location where nutrients aren't accessible to most populations.

Nutrient Cycling

Movement and exchange of nutrients between living organisms and the environment through biogeochemical cycles.

Micronutrients

Nutrients needed in small amounts (e.g., iron, zinc, copper).

Transformation

A process that changes a nutrient's chemical form (e.g., photosynthesis, respiration, nitrification).

Leaching

Loss of nutrients from soil as they dissolve in water and are carried away.

Carbon Cycle

The continuous movement of carbon among the atmosphere, oceans, soil, plants, and animals.

Photosynthesis

Process where plants use CO₂, water, and sunlight to make glucose and oxygen.

Respiration

Process where organisms use oxygen to break down glucose, releasing CO₂ and energy.

Combustion

Burning of fossil fuels or biomass, releasing CO₂ into the atmosphere.

Biomass

Total mass of living matter in a given area.

Nitrogen Cycle

Process that moves nitrogen through the atmosphere, soil, and organisms.

Fixation

Conversion of atmospheric N₂ into ammonia (NH₃) by bacteria or lightning.

Nitrification

Conversion of ammonia (NH₃) into nitrates (NO₃⁻) by bacteria.

Assimilation

Uptake of nitrates or ammonia by plants to make proteins and nucleic acids.

Ammonification

Decomposition of organic nitrogen into ammonia by bacteria and fungi.

Denitrification

Conversion of nitrates (NO₃⁻) back into nitrogen gas (N₂), returning it to the atmosphere.

Proteins / DNA / RNA

Molecules that require nitrogen as a key element for structure and function.

Phosphorus Cycle

Movement of phosphorus through rocks, soil, water, and living organisms.

Weathering

Breakdown of rocks, releasing phosphate into soil and water.

Erosion

Movement of weathered material (and nutrients) by wind or water.

Assimilation (Phosphorus)

Plants absorb phosphate from soil; animals get it by eating plants.

Decomposition

Breakdown of organic matter, returning phosphorus to the soil.

Lithification

Formation of rocks from sediments, trapping phosphorus in geologic reservoirs.

Geologic Reservoir

Long-term storage of nutrients in rock or sediment layers.

Tectonic Processes

Movement of Earth's crust that can uplift rocks and expose new phosphate sources.

Sulfur Cycle

Circulation of sulfur through the atmosphere, land, and living organisms.

Coal Combustion

Burning of coal releases sulfur dioxide (SO₂) into the atmosphere.

Eutrophication

Excess nutrients (nitrogen, phosphorus) in water cause overgrowth of algae and oxygen depletion.

Red Tide (Algal Bloom)

Rapid growth of toxic algae, often caused by nutrient pollution.

Cyanobacterial Bloom

Overgrowth of blue-green algae due to high nitrogen and phosphorus.

Acid Precipitation

Rain containing acids formed when sulfur dioxide and nitrogen oxides react with water.

Ocean Acidification

Absorption of excess atmospheric CO₂ by oceans, lowering pH and harming marine life.

Increased Atmospheric Carbon

Rising CO₂ levels from burning fossil fuels, contributing to climate change.