AP Environmental Science Lecture Notes Review

A comprehensive set of vocabulary flashcards covering the major units of AP Environmental Science, including ecosystems, populations, earth systems, energy, and global change, and pollution.

Competition

A community interaction where individuals fight for limited resources.

Mutualism

A symbiotic relationship where both species benefit from each other.

Commensalism

A relationship where one species benefits while the other is neither harmed nor benefited.

Parasitoids

Insects whose larvae develop in or on the bodies of other insects, eventually killing them.

Tropical Rainforest

A biome with great diversity, high primary productivity, and acidic soil, receiving $200-400\,cm$ of rain per year.

Tundras

An ecosystem characterized by little to no vegetation, permafrost soil, and little to no Net Primary Productivity (NPP).

Estuaries

Partially enclosed coastal bodies of water where freshwater from rivers mixes with saltwater from the ocean.

Euphotic Zone

The upper layer of ocean water that receives sunlight, is the warmest region, and contains high levels of dissolved oxygen ($DO$).

Oligotrophic Lakes

Young, deep, nutrient-poor lakes with clear water and low phytoplankton levels.

Eutrophic Lakes

Old, shallow lakes that are nutrient-rich with murky water, high organic matter, and low oxygen ($O_2$) levels.

Carbon Sinks

Reservoirs that store more carbon than they release, such as forests and oceans.

Limestone

The largest carbon reservoir on Earth.

Nitrogen Fixation

The process where bacteria or lightning convert $N_2$ into ammonia ($NH_3$).

Transpiration

The process by which plants release water vapor into the atmosphere through stomata.

Genetic Diversity

The range of genetic traits, both expressed and recessive, that make up the gene pool for a species.

Species Richness ($r$)

The total number of different species in an ecosystem.

Bottleneck Event

An environmental disturbance that drastically reduces population size and kills organisms independently of their genome.

Provisioning Services

Ecosystem services providing goods taken directly from nature, such as wood, paper, and fish.

Island Biogeography Rule 1

Larger islands support more total species and have lower extinction rates.

Succession

The gradual and orderly process of an ecosystem's development brought about by changes in community composition.

Pioneer Species

The first organisms to appear in succession, often having wide ranges of tolerance to adapt to new habitats.

Carrying Capacity ($K$)

The maximum population size that a species can sustainably be supported by the available resources in an environment.

$R-Selected$ Species

Species with many offspring, low parental care, shorter lifespans, and high population growth (Type III survivorship).

$K-Selected$ Species

Species whose populations are limited by carrying capacity, having few offspring and high parental care (Type I survivorship).

Replacement Birth Rate

The number of children a couple must have to replace themselves in a population, typically $2.1$.

Malthusian Theory

The theory that human population growth is happening faster than the growth of food production.

Convergent Plate Boundaries

Tectonic plates moving toward each other, resulting in subduction zones, mountains, or island arcs.

Porosity

The amount of empty space in a soil; for example, sand has high porosity while clay has low porosity.

Permeability

How easily water can drain through a soil.

Troposphere

The lowest layer of the atmosphere where weather occurs and temperature decreases as altitude increases.

Stratosphere

The second atmospheric layer containing the beneficial ozone layer that absorbs $UV-B$ and $UV-C$ radiation.

Coriolis Effect

The influence of Earth's rotation on the direction of winds and ocean currents.

Albedo

The measure of how much solar energy is reflected from Earth's surface back into space.

El Niño (ENSO)

A phenomenon where southern trade winds weaken or reverse, blowing warm water toward the Americas and suppressing upwelling.

Tragedy of the Commons

The theory that shared resources will be overused and depleted by individuals acting in their own self-interest.

Drip Irrigation

The most efficient irrigation method using perforated hoses to release water to roots, losing only $5\%$ to runoff and evaporation.

Confined Aquifer

An underground water source surrounded by a layer of impermeable rock that impedes water flow.

CAFOs

Concentrated Animal Feeding Operations; facilities where large numbers of animals are raised in a small area for meat consumption.

Ecological Footprint

The impact of an individual or society on the environment expressed as the amount of land required to sustain their resources.

Lignite

The least energy-dense and lowest quality type of coal.

Anthracite

The most energy-dense coal, which is the cleanest burning and almost pure carbon.

Fracking

Hydraulic fracturing; the process of releasing natural gas from shale rock by injecting fracturing fluid.

Nuclear Fission

The process of splitting the nucleus of an unstable element with neutrons to release energy.

Photovoltaic Solar Cells (PV cells)

Semiconductors that emit low-voltage electrical current when exposed to sunlight.

Geothermal Power

Energy obtained by using heat stored in the Earth's interior to heat water into steam for electricity.

Clean Air Act (1970)

A law empowering the EPA to monitor and enforce limits for six criteria pollutants: $NO_2$, $O_3$, $SO_2$, $CO$, Lead, and Particulate Matter.

Photochemical Smog

Air pollution formed by the reaction of $NO_x$, $VOCs$, and sunlight in the troposphere.

Thermal Inversion

A weather condition where cool air becomes trapped near the surface beneath a warmer air mass, trapping pollutants near the ground.

Wet Scrubbers

Air pollution control systems that use chemical agents and water sprays to remove both gaseous pollutants and particulate matter.

Primary Wastewater Treatment

The physical removal of large debris and solid waste from sewage using screens and settling.

Persistent Organic Pollutants (POPs)

Synthetic, human-made chemicals like $DDT$ and $PCBs$ that do not break down easily and accumulate in animal tissues.

Biomagnification

The increasing concentration of fat-soluble compounds as they move up the food chain/trophic cascade.

Lethal Dose $50\%$ ($LD_{50}$)

The dose of a chemical that kills $50\%$ of a test population.

Montreal Protocol

An international agreement that phased out the use of chlorofluorocarbons ($CFCs$) to protect the stratospheric ozone layer.

The Greenhouse Effect

The process where infrared radiation is trapped by gases like $CO_2$ and $CH_4$, warming the Earth's surface.

Ocean Acidification

The decrease in ocean $pH$ caused by increased atmospheric $CO_2$ reacting with water to form carbonic acid ($H_2CO_3$).

HIPPCO

An acronym for the main human threats to biodiversity: Habitat fragmentation, Invasive species, Population growth, Pollution, Climate change, and Overexploitation.