Ecology

Abiotic

Non-living parts of an ecosystem (e.g., sunlight, temperature, water).

Ammonification

Process where decomposers convert organic nitrogen into ammonia.

Autotroph

Organism that produces its own food (like plants via photosynthesis).

Biodiversity

The variety of life in an area (species, genes, ecosystems).

Biomass

The total mass of living organisms in a given area.

Biomes

Large geographic areas with similar climates and ecosystems (e.g., desert, tundra).

Biotic

Living parts of an ecosystem (e.g., animals, plants).

Camouflage

Adaptation that allows organisms to blend in with their surroundings.

Carnivore

Animal that eats only other animals.

Carrying Capacity

Maximum number of organisms an environment can support sustainably.

Character Displacement

Evolution of differences in traits to avoid competition.

Climax Community

Stable, mature ecosystem that no longer goes through major changes.

Combustion

Burning of fossil fuels that releases carbon dioxide into the atmosphere.

Commensalism

Relationship where one species benefits and the other is unaffected.

Community

All the different populations living in the same area.

Competition

When organisms fight for the same limited resource.

Competitive Exclusion

When one species outcompetes and eliminates another from a niche.

Consumer (1°, 2°, 3°)

Organisms that eat other organisms (primary consumes producers, secondary consumes primary, etc.).

Decomposer

Organism that breaks down dead material and recycles nutrients.

Denitrification

Process where bacteria convert nitrates into nitrogen gas.

Density-Dependent Limiting Factor

A factor affected by population size (e.g., disease, food).

Density-Independent Limiting Factor

A factor that affects population regardless of size (e.g., natural disasters).

Desert

Dry biome with little precipitation and extreme temperatures.

Detritus

Dead organic matter.

Detritivore

Organism that feeds on detritus (e.g., earthworms).

Ecosystem

All living and non-living things in a particular area.

Ectoparasite

Parasite that lives on the outside of its host.

Endangered Species

Species at risk of extinction.

Endoparasite

Parasite that lives inside its host’s body.

Energy Pyramid

Diagram showing energy flow through trophic levels.

Environment

Surroundings or conditions in which an organism lives.

Evaporation

Process by which water changes from liquid to gas.

Extinction

When a species no longer exists anywhere on Earth.

Food Chain

A linear series showing who eats whom in an ecosystem.

Food Web

Complex network of feeding relationships in an ecosystem.

Fossil Fuel

Energy source formed from ancient organic matter (e.g., coal, oil).

Grassland

Biome dominated by grasses with few trees.

Greenhouse Effect

Warming of Earth due to trapped heat by gases like CO₂.

Ground Water

Water stored underground in soil and rock.

Habitat

Natural environment where an organism lives.

Herbivore

Organism that eats only plants.

Heterotroph

Organism that eats others for energy.

Invasive Species

Non-native species that harms the environment.

Mimicry

When one species resembles another for protection.

Mutualism

Relationship where both species benefit.

Niche

Role or job of an organism in its environment.

Nitrification

Process where ammonia is converted to nitrates.

Nitrogen Fixation

Process where bacteria convert nitrogen gas into usable forms.

Nonnative Species

Organism introduced to a new area where it doesn’t naturally live.

Omnivore

Animal that eats both plants and animals.

Ozone Layer

Layer in the atmosphere that blocks harmful UV radiation.

Parasitism

Relationship where one organism benefits and the other is harmed.

Physical Defense

Physical traits used to protect an organism (e.g., thorns, shells).

Pioneer Species

First species to colonize a barren area.

Population

Group of the same species living in the same area.

Precipitation

Water falling from the sky (e.g., rain, snow, hail).

Predator

Organism that hunts and eats other organisms.

Prey

Organism that is hunted and eaten.

Primary Succession

Ecosystem development starting from bare rock (no soil).

Producer

Organism that makes its own food (usually through photosynthesis).

Rainforest

Lush biome with high rainfall and biodiversity.

Resource Partitioning

Dividing resources to reduce competition.

Saprophyte

Organism that feeds on decaying matter.

Scavenger

Animal that eats dead animals it didn’t kill.

Secondary Compound

Chemicals in plants used for defense.

Secondary Succession

Ecosystem recovery after disturbance (e.g., fire, flood).

Species Diversity

Number and variety of species in a community.

Species Evenness

How equal the populations of each species are.

Species Richness

Number of different species in a community.

Symbiosis

Close relationship between two species (mutualism, commensalism, parasitism).

Temperate

Climate with moderate temperatures, not extreme.

Deciduous Forest

Forest biome where trees lose leaves in fall.

Taiga

Cold forest biome with coniferous trees, also called boreal forest.

Transpiration

Process where water vapor is released from plants.

Trophic Levels

Levels in a food chain (producer, consumer, etc.).

Tropical

Warm, humid regions near the equator.

Tundra

Cold, treeless biome with permafrost.

Photosynthesis

Process by which plants make food from sunlight.

Cellular Respiration

Process of converting glucose into energy (ATP).

Runoff

Water that flows over the land surface into bodies of water.

Ecological Succession

Natural process of ecosystem change over time.

Climax Species

Species that dominate in a stable, mature ecosystem.

Biogeochemical Cycle

Pathway by which chemical substances move through biotic and abiotic components.

Indicator Species

Species that show the health of an ecosystem.

Keystone Species

Species that has a large impact on ecosystem stability.

Biosphere

All ecosystems on Earth; the global sum of life.

Adaptation

A trait that helps an organism survive and reproduce.

Limiting Factor

Anything that restricts the growth of a population.

Ecological Footprint

Impact of a person or community on the environment.

Pollution

Harmful substances released into the environment.

Overfishing

Depleting fish populations by excessive fishing.

Habitat Fragmentation

Splitting of ecosystems into smaller pieces.

Succession

Gradual change in species in an ecosystem over time.

Climate

Average weather conditions over a long time.

Weather

Day-to-day atmospheric conditions.

Natural Selection

Process where organisms better adapted to their environment survive and reproduce.

Bioremediation

Using living organisms to clean up environmental pollution.