AP Environmental Science Vocabulary

Flashcards of key vocabulary terms and definitions from the AP Environmental Science lecture notes on The Living World, Populations, Earth Systems, Land and Water Use, and Pollution.

Abiotic Components

Nonliving components of Earth, such as the atmosphere, hydrosphere, and lithosphere.

Biotic Components

Living components of Earth, such as animals, plants, fungi, protists, and bacteria, forming the biosphere.

Population

A group of organisms of the same species.

Community

Populations of different species that occupy the same geographic area.

Habitat

The area or environment where an organism lives or where an ecological community occurs.

Ecological Niche

The role and position a species has in its environment, including how it uses biotic and abiotic resources.

Competition

Occurs when two individuals compete for resources in the environment.

Resource Partitioning

Occurs when species coexist and share resources without conflict.

Predation

Occurs when one species feeds on another, driving changes in population size.

Symbiotic Relationships

Close, prolonged associations between two or more different organisms of different species.

Mutualism

Both organisms benefit from their relationship (e.g., pollinators and plants).

Commensalism

One organism benefits, and the other is neither harmed nor benefited (e.g., barnacles on scallops).

Parasitism

One organism benefits by harming the other organism (e.g., mistletoe on a tree).

Ecotones

Transitional area where two biomes meet.

Ecozones/Ecoregions

Small regions within ecosystems that have similar physical features.

Edge Effects

Ecotones have a great amount of species diversity and biological density.

Cell Respiration

Occurs when autotrophs make ATP from carbohydrates and other biomolecules.

Bioenergetics

The study of how energy flows through living organisms.

Autotrophs

Organisms that produce complex organic compounds from simple substances in the environment.

Heterotrophs

Organisms that consume other organisms in a food chain.

Food Chain

Shows how energy flows step by step from producer to consumers.

Energy Pyramid

Shows how much energy is available to each successive trophic level.

Food Webs

Shows the complex interactions between many species.

Ecosystem Diversity

Describes how variable an ecosystem is within a geographical location.

Biodiversity

The number and variety of organisms found in the world or in a particular habitat or ecosystem.

Evolution

The change in a population’s genetic composition over time.

Natural Selection

The natural selection of advantageous traits changes the makeup of a population.

Phylogenetic Tree

A diagram that shows how organisms are related based on evolutionary relationships.

Species

A group of organisms capable of breeding with one another but not with other species.

Speciation

The formation of new species from preexisting species.

Extinction

Occurs when a species cannot adapt quickly enough to environmental change and all members die.

Biological Extinction

Extermination of a species; no individuals of this species left on the planet.

Ecological Extinction

So few individuals of a species that this species can no longer perform its ecological function.

Commercial or Economic Extinction

A few individuals exist, but the effort needed to locate and harvest them is not worth the expense.

Provisioning Services

Physical items we obtain from our environment (e.g., food, raw materials, water, energy).

Cultural Services

Non-material benefits people obtain from the ecosystem (e.g., recreation, education, tourism).

Regulating Services

Benefits obtained from the regulating of ecosystems (e.g., pest control, water purification, climate regulation).

Support Services

Allow for other ecosystem services to be present (e.g., nutrient recycling and soil formation).

Keystone Species

Maintain the biotic balance in a community; their extinction would lead to a large change in the ecosystem.

Indicator Species

Used as a standard to evaluate the health of an ecosystem; used as an early warning system.

Primary Succession

Begins in a virtually lifeless area.

Secondary Succession

Takes place where an existing community has been cleared, but the soil has been left intact.

Pioneer Species

Organisms present in the first stages of either type of succession; have wide ranges of environmental tolerance.

Climax Community

Formed in the final stage of succession; has a dynamic balance between abiotic and biotic components.

Population Density

Number of individuals of a population that inhabit a certain unit of land or water area.

Population Dispersion

How individuals of a population are spaced within a region (clumped, uniform, random).

Biotic Potential

How much a population would grow if there were unlimited resources in the environment.

Carrying Capacity

The maximum population size that can be supported by the available resources in the region.

J-Curve Model

Exponential Growth model.

S-Curve

Logistic Population Growth model.

R-selected Organisms

Reproduces early in life, usually with a high capacity for reproductive growth (e.g., bacteria, algae).

K-selected Organisms

Reproduces later in life, produces fewer organisms, and devotes significant time and energy to nurturing offspring (e.g., humans, lions).

Boom-and-Bust Cycle

Very common among r-strategists, with rapid increase followed by an equally rapid drop-off.

Density-dependent Factors

Increased predation, competition for food, disease, buildup of toxic materials.

Density-independent Factors

Fires, storms, earthquakes.

Type I Survivorship Curve

The majority of offspring will live for a long period of time.

Type II Survivorship Curve

Offspring have a 50-50 chance of surviving to old age.

Type III Survivorship Curve

Most offspring die young, but if they live to a certain age, they will live a longer life.

Emigration

movement of people out of a population

Immigration

movement of people into a population.

Total Fertility Rate

the number of children a woman in a given population will bear during her lifetime

Replacement Birth Rate

the number of children a couple must have in order to replace themselves in a population.

Ecological Footprint

the environmental impact of a population

Extensive Pastoralism

the shifting of animal herds between grazing pastures

Desertification

a human process that turns a vegetated environment into a desert-like landscape

Irrigation

the application of controlled amounts of water to plants at needed intervals

Fragmentation

Habitats are broken into smaller pieces by, for example, building of roads and cities

Degradation

pollutants are added to the environment

Overexploitation

contribution to extinction

Tectonic Plates

parts of the lithosphere that float on the asthenosphere

Convergent Boundary

two plates are pushed toward and into each other

Divergent Boundary

two plates move away from each other

Transform Fault Boundary

two plates slide against each other in opposite directions

Subduction

an older and denser plate sinks beneath the younger and lighter plate

Earthquakes

geological events resulting from vibrations deep in the Earth that release energy

Volcanoes

geological events resulting from plate movement

Exosphere

Gases are thinnest.

Thermosphere

Gases are very thin and Auroras occur.

Ionosphere

Absorbs X-rays and ultraviolet radiation from Sun.

Mesosphere

Air pressure extremely low temperatures decreasing with altitude and where meteors usually burn up before striking Earth.

Stratosphere

Includes the ozone layer, atmosphere gases are not well mixed and gradually warmer with altitude.

Troposphere

Where weather takes place, usually well-mixed, altitude gradually colder and contains 99% of water vapor and clouds.

Weather

Day-to-Day properties; Wind Speed, Directions, Temperature, Amount of Sunlight, Pressure and Humidity.

Climate

Patterns that are constant over many years; Average Temperature and Average Precipitation Amounts.

Watershed

an area of land that collects rainwater and drains it into a particular stream or river

Water Stress

Water-stressed countries have a renewable annual water supply of about 1,000-2,000 m³ per person.

Water Scarcity

Water-scarce countries have a renewable annual water supply of less than 1,000 m³ per person

Water Conservation

Includes Policies, strategies, and activities to sustainably manage the natural resource of fresh water

Soil

A complex, ancient material teeming with living organisms; consists of finely broken-down or weathered rock, Living and dead organic matter, Air and Water.

Igneous Rocks

Rock is melted by heat and pressure below the crust.

Sedimentary Rocks

Forms as a sediment; builds up and is compressed.

Metamorphic Rocks

Formed by transforming an existing rock via a large amount of pressure and heat.

Physical Weathering

Rock is weakened and worn down by physical forces, usually wind or water.

Chemical Weathering

Rock is subjected to chemical alteration through reactions with water, oxygen, or dissolved minerals.

Biological Weathering

Weathering that takes place as the result of the activities of living organisms.

Monoculture

Leaches soil of specific nutrients and Decreases crop genetic diversity, making crops more susceptible to pests and diseases

Polyculture

Planting many types of crops in a large area; increases sustainability and limits nutrient depletion in soil

Conservation

the management or regulation of a resource

Preservation

the maintenance of a species or ecosystem in order to ensure its perpetuation

Fossil Fuels

Provide 65% of the world’s electricity and Formed from the fossilized remains of once-living organisms