Biogeochemical Cycles and Nutrient Dynamics

This set of flashcards covers key vocabulary and concepts related to biogeochemical cycles, nutrient dynamics, and ecological processes.

Biogeochemical cycle

A cycle that describes the movement of elements and compounds through biological and geological processes.

Reservoir

A natural or artificial storage space for fluids, such as water or carbon.

Source

A location or process that provides nutrients or elements to an ecosystem.

Sink

A process or location where nutrients or elements are stored or accumulated.

Biosphere

The global sum of all ecosystems, the zone of life on Earth.

Atmosphere

The layer of gases surrounding the Earth, essential for life.

Hydrosphere

All water elements on Earth, including oceans, rivers, lakes, and water vapor.

Lithosphere (geosphere)

The solid outer part of the Earth, consisting of the crust and upper mantle.

Nutrient cycling

The movement and exchange of organic and inorganic matter back into the production of living matter.

Matter conservation

The principle that matter cannot be created or destroyed, only transformed.

Energy flow

The transfer of energy from one part of an ecosystem to another, typically from producers to consumers.

Carbon dioxide (CO₂)

A greenhouse gas produced by respiration and combustion, essential for photosynthesis.

Carbon fixation

The process of converting inorganic carbon (CO₂) into organic compounds.

Photosynthesis

The process by which green plants use sunlight to synthesize foods with carbon dioxide and water.

Cellular respiration

The process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.

Decomposition

The breakdown of organic material by decomposers, returning nutrients to the ecosystem.

Decomposer

Organisms that break down dead or decaying organic material.

Detritivore

An organism that feeds on dead organic material, contributing to decomposition.

Organic molecules

Molecules that contain carbon and are found in living organisms.

Fossil fuels

Natural substances formed from the decomposed remains of ancient plants and animals, used as energy sources.

Carbon sink

A natural or artificial reservoir that absorbs more carbon than it releases.

Carbon source

Any natural or artificial process that releases carbon into the atmosphere.

Combustion

The chemical process of burning, which releases energy and carbon dioxide.

Carbon sequestration

The process of capturing and storing atmospheric carbon dioxide.

Ocean uptake (carbon absorption)

The process by which oceans absorb CO₂ from the atmosphere.

Nitrogen gas (N₂)

A colorless, odorless gas that makes up about 78% of the Earth's atmosphere.

Nitrogen fixation

The conversion of atmospheric nitrogen (N₂) into a usable form for plants.

Nitrogen-fixing bacteria

Bacteria that convert nitrogen gas into ammonia.

Ammonia (NH₃)

A compound of nitrogen and hydrogen that is a key part of nitrogen metabolism.

Ammonium (NH₄⁺)

The ion formed when ammonia combines with hydrogen ions.

Nitrification

The microbial process of transforming ammonia into nitrites and nitrates.

Nitrite (NO₂⁻)

A chemical compound formed during the nitrification process.

Nitrate (NO₃⁻)

A chemical compound essential for plant growth and formed from nitrites.

Assimilation (nitrogen assimilation)

The process by which plants and animals incorporate nitrogen into their tissues.

Ammonification

The process of decomposers converting organic nitrogen back into ammonia.

Denitrification

The process of converting nitrates back into nitrogen gas, completing the nitrogen cycle.

Denitrifying bacteria

Bacteria that convert nitrates into nitrogen gas.

Root nodules

Swellings on the roots of certain plants that house nitrogen-fixing bacteria.

Limiting nutrient

A nutrient that is scarce and thus limits the growth of organisms.

Evaporation

The process by which water changes from a liquid to a gas or vapor.

Condensation

The conversion of vapor into liquid water.

Precipitation

Any form of water, liquid or solid, that falls from the atmosphere to the Earth's surface.

Transpiration

The process by which water is absorbed by plants and released as water vapor.

Runoff

The flow of water over land, often carrying nutrients and pollutants into bodies of water.

Infiltration

The process by which water enters the soil from the surface.

Groundwater

Water that is stored beneath the Earth's surface in soil or rock formations.

Surface water

Water that collects on the surface of the ground.

Water vapor

Water in its gaseous state, a key component of the atmosphere.

Hydrologic cycle

The continuous movement of water on, above, and below the surface of the Earth.

Phosphate (PO₄³⁻)

A phosphorus compound that is vital for energy transfer and is a key nutrient.

Weathering

The breakdown of rocks into smaller particles by environmental factors.

Sedimentation

The process of settling or depositing sediment, often in water bodies.

Geological uplift

The process by which Earth's crust rises due to tectonic forces.

Runoff (phosphorus movement)

The movement of phosphorus from land to water bodies via surface water.

Limiting nutrient (phosphorus context)

Phosphorus that limits the growth of organisms, especially in aquatic ecosystems.

Eutrophication

The enrichment of water bodies with nutrients, leading to increased plant growth.

Algal bloom

Rapid increase of algae in water bodies, often due to nutrient overload.

Hypoxia

Low levels of dissolved oxygen in water, often resulting from algal blooms.

Dead zone

Areas in aquatic environments where oxygen levels are too low to support most marine life.

Nutrient runoff

The transportation of nutrients from land into water bodies, often due to rain.

Fertilizer pollution

Pollution resulting from the runoff of excess fertilizers into waterways.

Primary producer (autotroph)

Organisms that produce their own food, typically through photosynthesis.

Consumer (heterotroph)

Organisms that cannot produce their own food and must consume other organisms.

Food web

A complex network of interconnected food chains in an ecosystem.

Trophic level

The position an organism occupies in a food chain.

Biomass

The total mass of living matter within a given area or volume.

Nutrient availability

The accessibility of nutrients in the environment for organisms.

Macromolecules

Large molecules necessary for life, including carbohydrates, proteins, and nucleic acids.

Carbohydrates (carbon connection)

Organic compounds made from carbon, hydrogen, and oxygen that serve as a primary energy source.

Proteins (nitrogen connection)

Large molecules composed of amino acids that contain nitrogen, crucial for cellular functions.

Nucleic acids (nitrogen and phosphorus connection)

Molecules essential for all known forms of life, comprised of nucleotides that include nitrogen and phosphorus.

ATP (phosphorus connection)

A molecule that carries energy within cells, containing phosphorus.

Phospholipids

Lipids that are a major component of all cell membranes.

Ecosystem stability

The ability of an ecosystem to maintain homeostasis despite environmental changes.

Feedback loop (positive/negative)

A situation where outputs of a system either amplify or dampen the processes within that system.

Anthropogenic impact

Environmental changes caused or influenced by human activities.

Climate change (carbon cycle link)

Long-term alteration of temperature and typical weather patterns in a place linked to carbon emissions.