Biogeochemical Cycles - Key terms

What is the Hydrologic Cycle?

The water cycle

Evaporation

The process of water changing from a liquid to a gas/vapor

Condensation

The process of water changing from a gas/vapor into a liquid

Precipitation

Water released from clouds in the form of rain, freezing rain, sleet, snow, or hail

Collection

 When water collects and is stored on Earth

Transpiration

The process of water evaporating from plants 

Infiltration

The process by which precipitation (water) soaks into the ground through the soil and rock layers

Runoff

 Water (often mixed with other nutrients or chemicals) that “runs off” of the land

Erosion

When parts of the land (rocks, soil, etc) are worn away and transported by natural forces such as wind or water

What is the Carbon cycle?

The oxygen cycle

Organic

Carbon-based (all life on Earth is organic) 

Fossil fuels

Fuels made of fossilized, buried remains of plants and animals that lived millions of year ago (ex: coal, crude oil, natural gas)

Greenhouse gases

Gases in Earth’s atmosphere that contribute to the greenhouse effect

Greenhouse effect

A natural process that warms the Earth’s surface - Gases in Earth’s atmosphere trap heat from the sun that would otherwise escape back to space - the carbon emissions that humans are putting into the is increasing the effects of the greenhouse effect

Global warming

The phenomenon of rising average temperatures of Earth’s surface, oceans, and atmosphere over the past 100-200 years

Climate change

A change in global or regional climate patterns, in particular a change apparent from the mid to late 20th century onwards and attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels

Ecological footprint

The impact of a person or community on the environment, expressed as the amount of land required to sustain their use of natural resources

Nitrogen Cycle

Nitrogen cycle

Nitrogen gas (N2)

The form of nitrogen that makes up about 78% of the atmosphere (unusable to plants and animals)

Ammonia (NH3)

A form of nitrogen that cannot be directly used by animals and most plants - found in animal wastes and decomposing (dead) organisms

Nitrite (NO2)

A form of nitrogen that cannot be directly used by animals and most plants - also found in decomposing (dead) organisms 

Nitrate (NO3)

A form of nitrogen that plants use directly (plants love nitrates!) - also found in decomposing (dead) organisms

Nitrogen fixation

A process that certain bacteria perform, turning nitrogen gas (N2) into ammonia (NH3)

Legumes

A plant that has root nodules containing nitrogen-fixing bacteria in large quantities (examples: peanuts, peas, clover, alfalfa, beans, lentils)

Nitrification

A process that certain bacteria perform, turning ammonia (NH3) into nitrites (NO2) and then nitrites (NO2) into nitrates (NO3)

Denitrification

A process that certain bacteria perform, turning nitrates (NO3) back into nitrogen gas (N2)

Phosphorus Cycle

Phosphorus cycle

Phosphates

A form of phosphorus that plants use to grow (plants love phosphates!)

Weathering

The breaking down or dissolving of rocks and minerals by an agent of weathering (water, acids, salt, ice, etc.)

Leeching

The removal of dissolved phosphate from soil by vertical water movement 

Eutrophication

Excessive richness of nutrients (ex. Nitrates, phosphates, etc.) in a body of water, frequently due to runoff, which causes dense growth of plant life and death of animal life from lack of oxygen