Atmosphere & Earth
This sphere includes the solid rock and loose rock particles of Earth; it contains the crust, mantle, and core.
Geosphere
The organisms (usually plants or algae) that make their own food by photosynthesis.
Producers
The continuous movement of water on, above, and below Earth's surface (evaporation, condensation, precipitation, etc.).
Hydrological cycle/water cycle
The variety of life in all its forms and levels, including the variation of genes, species, and ecosystems.
Biodiversity
A close relationship between two species where both benefit from the interaction.
Mutualism
The gradual process of change and replacement of the types of species in a community following a disturbance.
Ecological succession
Species that produce many offspring, have early maturity, and little parental care (often boom-bust dynamics).
R-selected species
The short-term atmospheric conditions at a specific place and time (temperature, precipitation, wind).
Weather
The permanent loss of all members of a species.
Extinction
Planting and protecting young individuals of a threatened species in the wild or in controlled areas to increase population size.
Captive breeding/egg pulling where applicable
The lowest layer of Earth's atmosphere where weather occurs and where most living organisms live.
Troposhere
Organisms that obtain energy by eating other organisms; they cannot produce their own food.
Consumers
The long-term cycling of carbon between living organisms, the atmosphere, oceans, and rocks.
Carbon cycle
A species that can thrive in a wide range of environmental conditions and can make use of many different resources.
Generalist species
An interaction where one organism benefits and the other is neither helped nor harmed.
Commensalism
Succession that begins on newly exposed surfaces where no soil exists (e.g., after lava flow).
Primary ecological succession
Species that produce fewer offspring, invest more in parental care, and have stable population sizes near carrying capacity.
K-selected species
Long-term average of weather patterns in an area over decades; includes temperature and precipitation trends.
Climate
A species at very high risk of extinction across all or most of its range.
Endangered species
The practice of removing seeds or genetic material and storing them (often for rare plants) as an insurance policy.
Seed bank
The atmospheric layer above the troposphere containing the ozone layer that absorbs much of the Sun's ultraviolet radiation.
Stratosphere
The process by which plants, algae, and some bacteria convert sunlight, water, and carbon dioxide into glucose and oxygen.
Photosynthesis
The process in which excess nutrients (often nitrogen or phosphorus) cause algal blooms and oxygen depletion in water bodies.
Eutriphication
A species with a narrow ecological niche, relying on specific resources or conditions.
Specialist species
A relationship where one organism (the parasite) benefits while the other (the host) is harmed, often without immediate killing.
Parasitism
Succession that follows disturbance in an area where soil is already present (e.g., after a fire).
Secondary ecological succession
A graph that shows the proportion of individuals surviving at different ages for a species.
Survivorship curve
Gases such as CO2, CH4, and N2O that trap heat in the atmosphere and contribute to the greenhouse effect.
Greenhouse gas
Substances that become more concentrated as they move up a food chain, often harming top predators.
Biomagnification
A controlled, low-intensity fire set by managers to reduce fuel loads and maintain ecosystem health.
Prescribed burn
The movement of water across the surface of the land into rivers, lakes, and oceans after precipitation.
Surface runoff
The feeding level in a food chain or food web (e.g., producers, primary consumers, secondary consumers).
Trophic levels
The movement of water from the land surface into the subsurface, replenishing aquifers.
Groundwater
A species whose presence and role in an ecosystem have a disproportionately large effect on other organisms; its loss can drastically change the ecosystem.
Keystone species
When two species evolve in response to one another over time, such as a plant and its pollinator.
Coevolution
The maximum population size of a species that an environment can sustainably support over long term.
Carrying capacity
A rapid decline in population size, often due to exceeding carrying capacity or sudden environmental change.
Population crash
A dry region on the leeward side of a mountain range where descending air warms and dries out, reducing precipitation.
Rain shadow
The breaking up of continuous habitat into smaller, isolated patches, often caused by roads, agriculture, or development.
Habitat fragmentation
Trading debt relief for commitments to protect biodiversity and conserve natural areas—an international conservation financing tool.
Debt-for-nature swap
A water-bearing underground layer of permeable rock, sand, or gravel that stores and transmits groundwater.
Aquifer
Organisms that break down dead organic material, returning nutrients to the ecosystem.
Decomposers
A biogeochemical cycle essential for DNA, ATP, and phospholipids; this element cycles slowly because it lacks a gaseous phase under Earth surface conditions.
Phosphorous cycle
A measure focusing on the number of different species in an area (as opposed to genetic or ecosystem diversity).
Species diversity
The splitting of resources so that competing species use different portions, times, or methods to reduce direct competition.
Resource partitioning
A factor (abiotic or biotic) that restricts population growth (e.g., food, water, disease, space).
Limiting factor
The number of individuals per unit area or volume.
Population density
The increased diversity and ecological interactions at the boundary between two habitats or ecosystems.
Edge effect
A US law intended to protect imperiled species and their habitats (abbreviation accepted).
ESA/Endangered Species Act
The rearing of individuals in captivity to later release into the wild to rebuild wild populations.
Reintroduction/captive breeding program