APES Summer Vocab

AP Environmental Science

A class that studies how humans interact with the natural world, covering topic like ecosystems, biodiversity, pollution, energy, and climate change, with a focus on identifying and solving environmental problems.

Abiotic (Unit 1)

Non-living parts of an environment (water, sunlight, temperature, soil)

Biotic (Unit 1)

Living parts of an environment (plants, animals, bacteria)

Biodiversity (Unit 1)

The variety of life in an area

Ecosystem Services (Unit 1)

Benefits nature provides to humans (clean air, clean water, food)

Primary Productivity (Unit 1)

The rate at which plants convert sunlight into energy

Gross Primary Productivity (GPP) (Unit 1)

Total energy plants capture from the sun

Net Primary Productivity (NPP) (Unit 1)

Energy left for consumers after plants use some; NPP = GPP - Respiration

Trophic Levels (Unit 1)

Feeding levels in a food chain (plants, herbivores, carnivores); only ~10% of energy passes to the next level

Biogeochemical Cycles (Unit 1)

The movement of chemicals (carbon, nitrogen, water) through living and non-living things

Nitrogen Fixation (Unit 1)

Bacteria convert nitrogen gas (N2) from the air INTO a usable form for plants (goes INTO the soil)

Denitrification (Unit 1)

Bacteria convert soil nitrogen back OUT into nitrogen gas in the air (goes OUT of the soil)

Photosynthesis (Unit 1)

Plants use sunlight, CO2, and water to make food and oxygen

Producer (Unit 1)

Makes its own food via photosynthesis (plants, algae)

Consumer (Unit 1)

Eats other organisms for energy. Primary consumers (eat plants): cow, deer, rabbit, grasshopper. Secondary consumers (eat herbivores): frog, fox, snake. Tertiary consumers: hawk, shark, eagle. Omnivores: bear, human, raccoon

Decomposer (Unit 1)

Breaks down dead organisms and recycles nutrients back into the soil (fungi, bacteria)

Natural Selection (Unit 2)

Organisms best suited to their environment survive and reproduce more, driving evolution

Genetic Biodiversity (Unit 2)

The variety of genes within a species; more variety = better ability to adapt

Species Richness (Unit 2)

The total number of different species in an area

Species Evenness (Unit 2)

How balanced the amounts of each species are in an area

Ecological Tolerance (Unit 2)

The range of conditions (temperature, pH) a species can survive in

Ecological Succession (Unit 2)

The gradual change in species in an ecosystem over time after a disturbance

Natural Disruptions (Unit 2)

Natural events (fires, floods, volcanoes) that disturb ecosystems and can trigger succession

Keystone Species (Unit 2)

A species that, if removed, would cause the entire ecosystem to collapse, even if it wasn't very common (e.g., sea otters)

Indicator Species (Unit 2)

A species whose presence or absence signals ecosystem health (e.g., frogs and mayflies indicate clean water)

Island Biogeography (Unit 2)

Larger islands closer to the mainland have more species; size and distance determine biodiversity

Ecological Niche (Unit 2)

The full role a species plays in its ecosystem (what it eats, where it lives, how it interacts)

Succession (Unit 2)

The process of one community of species being replaced by another over time after a disturbance. Primary = starts on bare rock; Secondary = starts where soil already exists

Trophic Level (Unit 2)

A single step in the food chain representing what an organism eats and where it gets its energy from; ~90% of energy is lost as heat at each step going up

Exponential Growth (Unit 3)

Population grows at a constant rate with no limits; produces a J-shaped curve

Logistic Growth (Unit 3)

Population growth slows as it nears carrying capacity; produces an S-shaped curve

Carrying Capacity (K) (Unit 3)

The maximum population size an environment can sustainably support

K-Selected Species (Unit 3)

Few offspring, high parental investment, live near carrying capacity (e.g., elephants, humans)

r-Selected Species (Unit 3)

Many offspring, little parental care, reproduce fast (e.g., insects, mice)

Survivorship Curves (Unit 3)

Graphs showing when organisms die; Type I = die late (humans), Type II = die at constant rate (birds), Type III = die young (fish, plants)

Demographic Transition (Unit 3)

A country shifts through 4 stages from high birth/death rates to low birth/death rates as it develops economically

Population Pyramids (Unit 3)

Bar charts showing age and sex breakdown of a population; wide base = growing, narrow base = shrinking

Total Fertility Rate (TFR) (Unit 3)

Average number of children a woman has in her lifetime; replacement level = 2.1

Rule of 70 (Unit 3)

Doubling time = 70 divided by growth rate (%); e.g., 2% growth = population doubles in 35 years

Overshoot (Unit 3)

Population exceeds carrying capacity, usually followed by a crash

Density-Dependent Factors (Unit 3)

Controls that get stronger as population grows (disease, competition, predation)

Density-Independent Factors (Unit 3)

Controls that affect populations regardless of size (hurricanes, droughts, wildfires)

Albedo (Unit 4)

How reflective a surface is; ice/snow = high albedo (reflects heat), dark surfaces = low albedo (absorbs heat)

Coriolis Effect (Unit 4)

Earth's rotation deflects moving air and water; curves right in the Northern Hemisphere, left in the Southern

El Nino (ENSO) (Unit 4)

A climate pattern where unusually warm water builds up in the eastern Pacific Ocean, disrupting normal weather patterns and causing flooding, droughts, and storms in different parts of the world

Ocean Conveyor Belt (Unit 4)

Global ocean circulation driven by temperature and salt differences; distributes heat around Earth

Infiltration (Unit 4)

Water soaking down into the ground from the surface

Watershed (Unit 4)

An area of land that drains into the same river or body of water

Rain Shadow (Unit 4)

The dry side of a mountain; air rises and loses moisture on the wet side, then descends dry on the other side

Global Wind Belts (Unit 4)

Large wind patterns (trade winds, westerlies, polar easterlies) caused by uneven heating of Earth and the Coriolis Effect

Plate Tectonics (Unit 4)

Earth's crustal plates move slowly; causes earthquakes, volcanoes, and mountains

Hadley Cell (Unit 4)

An atmospheric circulation loop between the equator and 30 degrees latitude driven by the rising of warm air and sinking of cool air

Ferrel Cell (Unit 4)

An atmospheric circulation loop found in the mid-latitudes between 30 and 60 degrees latitude

Permeability (Unit 4)

How easily water flows through rock or soil (gravel = high permeability)

Porosity (Unit 4)

How much empty space rock or soil has that can hold water

Water Holding Capacity (Unit 4)

How much water soil retains after excess drains away; affected by organic matter and soil texture

Aquaculture (Unit 5)

Farming fish or other aquatic organisms in controlled environments

Green Revolution (Unit 5)

A period of greatly increased agricultural production made possible through advances in farming technology and science

Monocropping (Unit 5)

Growing only one crop species over a large area; efficient but increases vulnerability to pests and disease

Aquifer (Unit 5)

An underground layer of rock or sediment that stores groundwater

Cone of Depression (Unit 5)

When too much groundwater is pumped out of a well, the water table around it drops and forms a cone-shaped dip

Integrated Pest Management (IPM) (Unit 5)

Pest control that combines biological, cultural, and chemical methods to minimize environmental harm

Salinization (Unit 5)

Salt buildup in soil from over-irrigation, making it infertile over time

Tragedy of the Commons (Unit 5)

Shared resources get overused because individuals each act in their own self-interest

CAFOs (Unit 5)

Large industrial farms where animals are raised in tight confined spaces; produce significant waste and greenhouse gases

Clearcutting (Unit 5)

Cutting down all trees in an area at once; causes habitat loss, erosion, and biodiversity loss

Desertification (Unit 5)

Fertile land turns into desert due to drought, overgrazing (animals eating too much vegetation), or deforestation (clearing of forests)

Urban Sprawl (Unit 5)

The spread of cities into surrounding rural land; causes habitat loss and increased car dependency

1st Law of Thermodynamics (Unit 6)

Energy cannot be created or destroyed, only converted from one form to another

2nd Law of Thermodynamics (Unit 6)

Every energy conversion loses some energy as heat; no process is 100% efficient

Fractional Distillation (Unit 6)

Crude oil is heated and separated into products (gasoline, diesel, jet fuel) based on boiling points

Nuclear Fission (Unit 6)

A large atom (uranium) is split, releasing large amounts of energy; used in nuclear power plants

Nuclear Fusion (Unit 6)

Two small atoms are joined, releasing enormous energy; powers the sun but not yet practical for power plants

Photovoltaic Cell (Unit 6)

A solar cell that converts sunlight directly into electricity

Half Life (Unit 6)

The time it takes for half of a radioactive substance to decay; longer half life = more dangerous long-term

Fracking (Unit 6)

High-pressure fluid is injected into rock to release trapped natural gas or oil; risks include groundwater contamination

Geothermal Energy (Unit 6)

Energy from heat inside the Earth; low emissions but only available in certain locations

Biomass (Unit 6)

Organic material (wood, crops, waste) burned as fuel; renewable but still releases CO2

Hydroelectric Power (Unit 6)

Electricity generated by the flow of water through a dam; renewable but disrupts river ecosystems

Tar Sands (Unit 6)

A mixture of sand and heavy oil that requires a lot of energy to extract and process into fuel

Turbine (Unit 6)

A machine with spinning blades that converts moving water, steam, or wind into electricity

Anthropogenic (Unit 7)

Caused by human activity

Catalytic Converter (Unit 7)

A car device that converts harmful exhaust gases (CO, NOx, hydrocarbons) into less harmful ones (CO2, N2, H2O)

Primary Pollutants (Unit 7)

Pollutants released directly into the air (e.g., CO, SO2, soot)

Secondary Pollutants (Unit 7)

Pollutants formed in the atmosphere when primary pollutants react with each other or sunlight (e.g., ozone, acid rain)

Criteria Pollutants (Unit 7)

The 6 most harmful air pollutants the government monitors and sets limits on: CO, SO2, NOx, ozone, particulate matter, and lead

Thermal Inversion (Unit 7)

A layer of warm air traps cold, polluted air near the ground, preventing pollutants from dispersing and worsening air quality

Volatile Organic Compounds (VOCs) (Unit 7)

Carbon-based chemicals that evaporate easily; react with NOx in sunlight to form smog

Photochemical Smog (Unit 7)

Brown hazy pollution formed when sunlight reacts with NOx and VOCs; contains ground-level ozone and harms lungs

Acid Deposition (Unit 7)

SO2 and NOx react with water in the atmosphere and fall as acid rain (wet) or dry acid particles; damages ecosystems and buildings

Electrostatic Precipitator (Unit 7)

Uses electric charges to pull dust and particles out of factory exhaust before release

Wet Scrubbers (Unit 7)

Spray water into exhaust to trap and remove pollutants (especially SO2) before they enter the air

Bioaccumulation (Unit 8)

A toxic substance (e.g., mercury) builds up in one organism's body over its lifetime

Biomagnification (Unit 8)

Toxin concentration increases at each trophic level; top predators are most affected and have the highest concentrations

Eutrophication (Unit 8)

When excess nutrients (nitrogen and phosphorus) from fertilizer runoff enter a body of water, causing a massive algae bloom. When the algae die, bacteria decompose them and use up all the dissolved oxygen, creating a dead zone where fish and other aquatic life cannot survive

LD50 (Lethal Dose 50) (Unit 8)

The dose that kills 50% of a test group; lower LD50 = more toxic

Nonpoint Source (Unit 8)

Pollution from many spread-out, hard-to-trace sources (e.g., farm runoff, stormwater)

Point Source (Unit 8)

Pollution from one specific, identifiable location (e.g., a factory pipe or sewage outfall)

Runoff (Unit 8)

Water flowing over land into streams and rivers, often carrying pollutants and sediment

Leachate (Unit 8)

Liquid that seeps through a landfill, picking up toxic chemicals and potentially contaminating groundwater