Ecosystem: Living things and their nonliving surroundings interacting Biome: A large region defined by climate and typical plants and animals Producer: An organism that makes its own food, usually by photosynthesis Consumer: An organism that eats other organisms Decomposer: An organism that breaks down dead matter Trophic level: A feeding position in a food chain Ten percent rule: About 10 percent of energy passes to the next trophic level Net primary productivity: Energy stored by producers after their own use Food web: Interconnected food chains Biodiversity: The variety of life at genetic, species and ecosystem levels Keystone species: A species with an outsized role in its ecosystem Indicator species: A species whose health signals environmental condition Invasive species: A non-native species that spreads and harms the ecosystem Ecological succession: Gradual replacement of communities over time Primary succession: Colonization of bare rock with no soil Secondary succession: Regrowth after disturbance where soil remains Carbon cycle: Movement of carbon among air, living things, oceans and rocks Nitrogen fixation: Converting nitrogen gas into usable forms by bacteria Nitrogen cycle: Movement of nitrogen through air, soil and organisms Phosphorus cycle: Movement of phosphorus through rock, soil and water, with no gas phase Hydrologic cycle: Circulation of water through evaporation, condensation and precipitation Photosynthesis: Making sugars from carbon dioxide, water and light Cellular respiration: Releasing energy from sugar using oxygen Carrying capacity: Largest population an environment can sustain r-selected species: Many offspring, little care, small body, short life K-selected species: Few offspring, much care, large body, long life Limiting factor: A resource that restricts population growth Population density: Individuals per unit area Age structure diagram: Graph of the population in each age group Total fertility rate: Average children per woman over her lifetime Replacement level fertility: About 2.1 children per woman Demographic transition: Shift from high to low birth and death rates Plate tectonics: Earth's crust moves in large plates Subduction: One plate sliding beneath another Soil horizon: A layer of soil, such as topsoil Soil erosion: Removal of soil by wind or water Loam: Balanced soil of sand, silt and clay Cation exchange capacity: Soil's ability to hold nutrients Weather: Short-term atmospheric conditions Climate: Long-term pattern of weather Troposphere: Lowest atmospheric layer where weather occurs Stratosphere: Atmospheric layer containing the ozone layer Coriolis effect: Earth's rotation bends wind and ocean currents El Nino: Periodic warming of the eastern Pacific altering weather worldwide Thermohaline circulation: Global ocean circulation driven by temperature and salt differences Rain shadow: A dry region on the leeward side of a mountain Upwelling: Rise of cold, nutrient-rich water to the surface Renewable resource: A resource that replenishes naturally in human time Nonrenewable resource: A resource that is used up faster than it forms Fossil fuels: Coal, oil and natural gas from ancient organisms Peak oil: The point of maximum oil production before decline Hydroelectric power: Electricity from flowing water Solar photovoltaic: Panels that convert sunlight directly into electricity Wind turbine: Machine converting wind energy to electricity Geothermal energy: Heat from Earth's interior used for power or heating Biomass: Organic matter burned or converted for energy Nuclear fission: Splitting atoms to release energy Energy efficiency: Doing the same work with less energy Cogeneration: Using waste heat from electricity production Overgrazing: Livestock eating plants faster than they regrow Monoculture: Planting one crop over a large area Crop rotation: Alternating crops to maintain soil No-till farming: Planting without plowing to protect soil Contour plowing: Plowing along slopes to reduce runoff Integrated pest management: Combining methods to control pests with minimal chemicals Aquaculture: Raising fish or other aquatic organisms Clear-cutting: Removing all trees from an area Deforestation: Large-scale removal of forest Urban heat island: City warmer than surroundings due to pavement and buildings Sprawl: Low-density development spreading from a city Ecological footprint: Land and water area needed to support a person or population Point source pollution: Pollution from a single identifiable source Nonpoint source pollution: Pollution from many diffuse sources, like runoff Eutrophication: Nutrient overload causing algae blooms and oxygen loss Dissolved oxygen: Oxygen in water, essential for aquatic life Biochemical oxygen demand: Oxygen used by microbes to break down organic waste Bioaccumulation: Buildup of a substance within an organism over time Biomagnification: Increasing concentration of a substance up the food chain Smog: Haze from air pollution, often ozone-rich Acid rain: Precipitation made acidic by sulfur and nitrogen oxides Particulate matter: Tiny solid or liquid particles in the air Tropospheric ozone: Ozone near the ground, a harmful pollutant Stratospheric ozone depletion: Thinning of the ozone layer by CFCs Montreal Protocol: Treaty phasing out ozone-depleting chemicals Greenhouse effect: Atmospheric gases trapping heat Greenhouse gases: Carbon dioxide, methane, nitrous oxide and water vapor Global warming potential: A gas's heat trapping relative to carbon dioxide Ocean acidification: Falling ocean pH as seawater absorbs carbon dioxide Albedo: Reflectivity of a surface Carbon footprint: Greenhouse gases produced by an activity or person Carbon sequestration: Capturing and storing carbon Municipal solid waste: Everyday trash from homes and businesses Sanitary landfill: Engineered site where waste is buried and covered Leachate: Liquid that drains from waste Hazardous waste: Waste that is toxic, reactive, corrosive or flammable Reduce, reuse, recycle: Waste management priorities in order Endangered species: A species in danger of going extinct Endangered Species Act: US law protecting species at risk CITES: Treaty regulating trade in endangered species Clean Air Act: US law setting air quality standards Clean Water Act: US law regulating water pollution Tragedy of the commons: Shared resources are overused when everyone acts alone Environmental impact statement: A report assessing a project's environmental effects Free flashcards from Peabody at peabody.kids/flashcards/tp-ap-environmental-science