Biogeochemical Cycles Flashcards

A set of vocabulary flashcards covering key terms and concepts from the Carbon, Nitrogen, Phosphorus, and Hydrologic biogeochemical cycles.

Biogeochemical Cycles

The movement of matter within and between ecosystems, involving biological, chemical, and geological processes.

Reservoirs

Components of biogeochemical cycles that contain matter, such as air, water, and living organisms.

Source

A term used to describe the phenomenon of molecules leaving a reservoir.

Sink

A term used to describe the phenomenon of molecules entering a reservoir.

Carbon Cycle

The movement of carbon around the biosphere, where it is held in living organisms for short periods and stored in rocks, soil, and fossil fuels for long periods.

Photosynthesis (Carbon Cycle)

The process by which plants and algae use solar energy to convert atmospheric $\text{CO}_2$ and water into glucose ($\text{C}_6\text{H}_{12}\text{O}_6$) and oxygen.

Respiration (Carbon Cycle)

A cellular process converting glucose and oxygen into gaseous $\text{CO}_2$, water, and ATP.

Exchange (Carbon Cycle)

The process of carbon traveling between the atmosphere and the ocean via evaporation and dissolving in both directions.

Burial (Carbon Cycle)

The process where dead biomass is incorporated into ocean sediment and fossilized over long periods.

Extraction (Carbon Cycle)

The human process of removing fossil fuels from the Earth.

Combustion (Carbon Cycle)

The burning of fossil fuels by humans or the natural burning of organic matter, which releases carbon into the atmosphere.

Greenhouse Gases

Gases in the atmosphere that trap heat near the Earth's surface and help regulate Earth's temperature.

Global Warming

Increases in global temperatures resulting from human activity producing higher concentrations of greenhouse gases.

Limiting Nutrients

Nutrients required for the growth of organisms that are available in lower quantities than other nutrients, thereby restricting plant and organism growth.

Nitrogen Cycle

The movement of nitrogen around the biosphere among reservoir sources and sinks, where most reservoirs only hold nitrogen for short periods.

Nitrogen Fixation

The process of converting gaseous atmospheric $\text{N}_2$ into a usable form for plants, carried out by cyanobacteria in the soil.

Nitrification

The conversion of ammonia into nitrite and then nitrate by nitrifying bacteria in soil around plant roots.

Assimilation (Nitrogen Cycle)

The process where plants and algae take up nitrogen from the soil through their roots and incorporate it into their tissues.

Mineralization / Ammonification

The process where decomposers break down organic matter from dead organisms and convert it back into inorganic compounds like ammonium.

Denitrification

The process of converting nitrate from soil or water into nitrous oxide and then back into atmospheric nitrogen gas.

Leaching (Nitrogen Cycle)

The process of dissolved molecules, such as nitrates, traveling down through soil and groundwater.

Phosphorus Cycle

The movement of phosphorus around the biosphere between sources and sinks, occurring primarily between land and water with no gas phase.

Assimilation (Phosphorus Cycle)

The process by which plants and animals take up inorganic phosphorus from the environment and assimilate it into tissues as organic phosphorus.

Mineralization (Phosphorus Cycle)

The process where waste products and dead organic tissue are decomposed by fungi and bacteria, converting organic phosphorus back to inorganic phosphorus.

Sedimentation (Phosphorus Cycle)

The process in water where phosphorus precipitates out of solution and settles as ocean sediments.

Geologic Uplift

Geologic forces that lift ocean sediment layers higher over time until they become mountain rocks.

Weathering

The process by which mountain rocks are slowly broken down by natural forces, returning phosphorus to terrestrial and aquatic habitats.

Algal Bloom

A rapid increase in the algal population of a waterway, often caused by phosphorus leaching from agricultural runoff.

Hypoxic

Refers to water that is low in oxygen, occurring when algae decomposition after an algal bloom consumes available oxygen.

Dead Zone

A region in an aquatic ecosystem created by hypoxic conditions where oxygen levels become so low that fish and other aquatic animals die.

Hydrologic Cycle

The cycle describing the movement of water through the biosphere, essential for cellular movement, nutrient transport, and toxin removal.

Transpiration

The release of water vapor from plant leaves into the atmosphere during photosynthesis.

Evaporation

The process of liquid water heating up and turning into gaseous water vapor that enters the atmosphere from aquatic biomes.

Evapotranspiration

The combined total amount of water transferred to the atmosphere via evaporation and plant transpiration.

Runoff

Water from surface sources that moves across the land surface and flows into streams, rivers, and oceans.

Infiltration

The process of surface water moving through soil and collecting in groundwater sinks known as aquifers.

Condensation

The process of atmospheric water vapor cooling and changing into liquid water to form clouds.

Precipitation

Liquid water falling or dripping from clouds in the atmosphere to the Earth's surface.