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Biogeochemical cycle

“The movement and recycling of matter through living organisms and the physical environment.”

Hydrologic cycle

“The continuous movement of water among the atmosphere, land, oceans, and organisms.”

Evaporation

“The conversion of liquid water into water vapor.”

Transpiration

“The release of water vapor from plants.”

Condensation

“The conversion of water vapor into liquid water.”

Precipitation

“Water that falls from the atmosphere to Earth's surface.”

Surface runoff

“Water that flows across the land surface.”

Infiltration

“The movement of water into the soil.”

Percolation

“The downward movement of water through soil and porous rock.”

Groundwater

“Water stored beneath Earth's surface.”

Water table

“The upper boundary of the saturated groundwater zone.”

Aquifer

“A permeable underground layer that stores and transmits groundwater.”

Respiration

“The process by which organisms break down organic molecules and release carbon dioxide.”

Combustion

“The burning of material that releases stored carbon into the atmosphere.”

Assimilation

“The uptake of inorganic nitrogen by organisms and its incorporation into organic molecules.”

Eutrophication

“The enrichment of water with nutrients, causing excessive algal growth and oxygen depletion.”

Weathering

“The physical or chemical breakdown of rock that can release phosphate.”