AP Environmental Science 2024 Review

By: Jordan Melamed

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Table of Contents (with hyperlinks)

Unit 1: The Living World: Ecosystems

• The nonliving/abiotic elements: range of temperatures, humidity, rainfall, and nutrients that are present

• Living/biotic elements: species of plants, animals, fungi, and bacteria (all affect the species’ likelihood of obtaining resources and persisting in an ecosystem)

• Community ecology: the study of interactions among species

• Symbiosis: two species are living in a close and long-term association with one another in an ecosystem

• Biosphere; the combination of all ecosystems on Earth; the region of our planet where life resides (20-km thick layer around Earth between the ocean bottom and highest mountain peak)

• Competition: the struggle of individuals, either within or between species, to obtain a shared limited resource

  • Research done by Geogry Gause (single-cell eukaryotes in the genus Paramecium affecting population growth) led to the competitive exclusion principle (two species competing for the same limiting resource cannot coexist) 

    • Under a given set of environmental conditions, when two species have the same realized niche, one species will perform better and will drive the other species to extinction

• Resource partitioning: caused by competition; two species evolve to divide a resource based on differences in their behavior and morphology

  • When competition reduces the ability of individuals to survive and reproduce, natural selection will favor individuals of one species that overlap less with individuals of another species in the resource they use

• Predation: an interaction in which one animal typically kills and consumes another animal (example: African lions eat gazelles)

  • Parasitoids: a specialized type of predator that lays eggs  inside other organisms (aka the host) → eggs hatch and the parasitoid larvae slowly consumes the host from the inside out → host dies (examples: wasps and flies)

  • To avoid being eaten or harmed by predators, many prey species have evolved defenses; behavioral, morphological, chemical, or mimicking another species’ defense

    • Behavioral: hiding and reduced movement

    • Morphological: camouflage and spines

    • Chemical: emitting chemicals

    • Mimic: nontoxic species mimicking toxic species

  • Parasitism: an interaction in which one organism lives on or in another organism (the host)

    • Parasites typically consume a small fraction of their host (one parasite rarely causes the death of the host) (example: tapeworm)

      • Parasites cause diseases in their hosts (aka pathogen); pathogens include viruses, bacteria, fungi, protists, and wormlike organisms (helminths)

  • Herbivory: when an animal consumes plant or algae

    • When herbivore populations increase, they can have dramatic effects on the abundance of plants and algae as well as the species composition that remains

• Mutualism: the interaction between two species that increases the chances of survival or reproduction for both species; ultimately each species is assisting the other species to benefit itself 

  • Natural selection will favor individuals that no longer engage in the mutualistic interaction

  • Example: Coral reefs consist of tiny coral animals that build the reefs and they provide a home to a particular species of algae; the algae provides the coral with sugars (produce via photosynthesis) → if the algae dies so does the coral

    • Photosynthesis: the process by which plants and algae use solar energy to convert carbon dioxide (CO2) and water (H2O) into glucose (C6H12O6) and oxygen (O2)

• Commensalism: an interaction between two species in which one species benefits and the other species is neither harmed nor helped

  • Example: many species of fish use coral reefs as hiding places to avoid predators; the fish receive a major benefit from the coral but the coral is neither harmed nor benefited by the fish’s presence 

• Native Species: species that live in their historical range, typically where they have lived for thousands or millions of years

  • Humans frequently move animals, plants, and pathogens around the world OR species move accidentally (example: a rat that stowed away in a shipping container and was shipped across by accident)

• Exotic/Alien Species: species that live outside their historical range 

  • Invasive Species: an exotic species that spreads rapidly across large areas and causes harm (often have no natural enemies in the regions introduced → they harm the native population that has natural enemies)

• Biome: the plants and animals that are found in a particular region of the world

  • A major factor that determines whether a species can survive and reproduce in a particular terrestrial region depends on the annual patterns of temperature and precipitation 

  • Climate diagrams help us understand how humans have used different biomes for different purposes

• Terrestrial Biomes: geographical regions of land categorized by a particular combination of average annual temperature, annual precipitation, and distinctive plan growth forms that are adapted to that climate

  • Tundra: cold and treeless biome, with low-growing vegetation; in the winter, the soil is completely frozen 

    • Examples: Russia, Canada, Scandinavia, Alaska, and edges of Antarctica

    • alpine tundras can be found on high mountains (where high winds and low temperatures prevent tree growth)

    • Permafrost: an impermeable, permanently frozen layer of soil that prevents water from draining and roots from penetrating (prevents deep-rooted plants/trees from living in the tundra)

  • Taiga/Boreal Forest: primarily coniferous/cone-bearing evergreen trees that can tolerate cold winters and short,cool growing seasons in the summer

    • Examples: 50° N and 60° N in Europe, Russia, and North America 

    • Cold climate with constrained plant growth due to temperature and low precipitation 

    • Waxy needles on evergreen trees contain compounds resistant to decomposition → taiga soils covered in a thick layer of organic material (soils are poor in nutrients)

  • Temperate Rainforest: a coastal biome typified by moderate temperatures and high precipitation

    • Examples: northern California to Alaska, southern Chile, Tasmania, and west coast of New Zealand

    • Ocean currents along these coasts help moderate temperature fluctuations and provide a source of water vapor → relatively mild summers and winter and a (nearly) 12 month growing season

    • Rainy winters and foggy summers

  • Temperate Seasonal/Deciduous Forest: a biome with warm summers and cold winters with over 39 inches of annual precipitation

    • Examples: eastern United States, Japan, China, Europe, Chile, and eastern Australia

    • Warmer summers and colder winters (compared to temperate rainforests); warm summers favor rapid decomposition 

    • Dominated by broadleaf deciduous trees (beech, maple, oak, and hickory) 

  • Shrubland/Woodland/Chaparral/Matorral/Mallee/Fynbos/Maquis: hot, dry summers and mild, rainy winters

    • Examples: southern California coast, southwestern Australia, southern Africa, Mediterranean Sea region

    • Plant growth is constrained by high temperatures and low precipitation in the summer and cool temperatures and higher precipitation in winter

  • Temperate Grassland/Cold Desert/prairies/pampas/steppes: cold, harsh winters and hot, dry summers

    • Examples: Great Plains of North America, South America, central Asia, and eastern Europe

    • Plant growth is constrained by insufficient precipitation in summer and cold temperatures in winter

    • Fires are common due to dry and frequently windy conditions (fan flamed ignited by lightning)

  • Tropical Rainforest: a warm and wet biome found between 20°N and 20°S of the equator

    • Examples: Central and South America, Africa, Southeast Asia, and northeastern Australia

    • Large tropical islands; oceans provide a constant source of atmospheric water vapor 

    • Commonly high precipitation → decomposition is extremely quick → lush vegetation takes up nutrients quickly (few nutrients left for the soil)

    • This biome faces deforestation due to agriculture because farmers want the tropical soils 

    • Contains more biodiversity per hectare than any other terrestrial biome

  • Savanna/Tropical Seasonal/Deciduous Forest: warm temperatures and distinct wet and dry seasons (precipitation during summer)

    • Examples: majority of Central America, Atlantic coast of South America, southern Asia, northwestern Australia, and sub-saharan Africa

    • In areas with the longest dry seasons, the tropical seasonal climate leads to the formation of savannas, relatively open landscapes dominated by grasses and scattered deciduous trees (acacia and baobab trees)

    • Grazins and fire discourage the growth of many smaller woody plants → open landscape

    • Warmer temperatures promote decomposition (however there is low precipitation) 

  • Hot Desert/Subtropical Desert: roughly 30°N and 30°S; hot temperatures, dry conditions, and sparse vegetation

    • Examples: Mojave Desert, Sahara, the Arabian Desert, and the Great Victoria Desert

    • Cacti, euphorbia plants, and succulent plants

    • To prevent water loss, the leaves of desert plants may be small, nonexistent, or modified into spines; thick outer layer with few pores for water and air exchange

• Aquatic Biomes: aquatic regions categorized by a particular combination of salinity, depth, and water flow; nearly 70% of Earth’s surface is covered by water

  • Freshwater Biomes: streams, rivers, lakes, ponds, or freshwater wetlands

  • Streams and Rivers: flowing freshwater thay may originate from underground springs or as runoff from rain or melting snow

    • Rivers are typically wider and carry larger amounts of water

    • Most streams and many rapidly flowing rivers have few plants or algae → inputs of organic matter from terrestrial biomes provide the energy required by organisms

    • insect larvae and crustaceans (crayfish) become predators for fish

    • Sediments and organic matter settle to the bottom and rooted plants and algae are better able to grow (alternative energy source for herbivores)

  • Lakes and Ponds: standing water, at least some of which is too deep to support plants that are rooted to the bottom and emerge above the water’s surface (aka emergent vegetation)

    • Lakes are bigger than ponds

    • Common fish in ponds and lakes include sunfish, bass, perch, and pike

    • Littoral Zone: shallow area of soil and water in lakes and ponds near the shore where most algae and emergent plants grow; also where most photosynthesis occurs

    • Limnetic Zone: zone of open water in lakes and ponds as deep as the sunlight can penetrate (rooted plants can no longer survive)

      • Phytoplankton: floating algae; the only photosynthetic organisms in this zone

    • Profundal Zone: a region of water where sunlight does not reach, below the limnetic zone in very deep lakes; plants and algae cannot survive here (nutrients are not easily taken up)

      • Bacteria decompose the detritus that recess this zone and consume oxygen → oxygen concentrations become so low that there is not enough oxygen to support larger organisms

    • Benthic Zone: muddy bottom of a lake, pond, or ocean beneath the limnetic and profundal zone

    • Oligotrophic Lakes: lakes that have low amounts of phytoplankton due to low amounts of nutrients in the water (phosphorus and nitrogen)

      • Given the low concentration of algae, oligotrophic lakes can look very clear for tens of meters down from the surface

      • Human activity in these lakes are causing increased nutrient inputs → less clear due to increased algae growth

    • Mesotrophic Lakes: lakes with a moderate level of fertility

    • Eutrophic Lakes: lakes with high level of fertility 

      • So fertile that their high concentrations of algae make the water turbid

  • Freshwater Wetlands: aquatic biomes that are submerged or saturated by water for at least part of each year, but shallow enough to support emergent vegetation 

    • Examples: swamps, marshes, and bogs; Great Dismal Swamp and the Okefenokee Swamp

    • Marshes: wetlands that contain primarily non-woody vegetation (cattails and sedges)

    • Bogs: very acidic wetlands that typically contain sphagnum moss and spruce trees

    • Most productive biomes on the planet and provide critical services that benefit humans and biodiversity:

      • Wetlands take in large amounts of rainwater and release it slowly into the groundwater or nearby streams (reduce the severity of floods and doughnuts)

      • Wetlands filter pollutants from water → recharging the ground with clean water

      • ⅓ of all endangered bird species in the United States spend some part of their lives in wetlands 

      • More than half of the freshwater wetland area in the United States has been drained for agriculture, development, or to eliminate breeding grounds (for mosquitoes and various disease-causing organisms) → less habitat for those species, reduces filter contaminants, and less sources for drinking, agriculture, and industries

  • Estuaries: areas along the coast where the fresh water of rivers mixes with salt water from the ocean; productive places for plants and algae which filter contaminants out of the water

    • Salt Marshes: contain non-woody emergency vegetation (just now in salt water)

      • Suffered from being filled in, being developed to support growing human populations, and being contaminated by pollutants that arrive from rivers that supply water

    • Estuaries and Salt Marshes provide important habitat for spawning fish and shellfish (⅔ of marine fish and shellfish species spend their larval stages in this biome)

  • Mangrove Swamps: tropical and subtropical coasts that contains trees whose roots are submerged in water

    • Mangrove trees are salt tolerant, often grow in estuaries but can be found along shallow coastlines that lack inputs of fresh water

    • The trees protect the coastlines from erosion and storm damage

    • ⅓ of the world’s mangrove swamps have been destroyed for human habituation or crops (rice and rubber trees)

  • Intertidal Zone: the narrow band of coastline that exists between levels of high and low tide

    • Range from steep, rocky areas to broad, sloping mudflats

    • Conditions can become quite harsh during low tide when organisms are exposed to direct sunlight, high temperatures, and desiccation/drying out

    • Home to barnacles, sponges, algae, mussels, crabs, and sea stars

    • Main threats are human causes like pollution, trash, chemicals, and oil spills

  • Coral Reefs: found in warm, shallow waters beyond the shoreline in tropical regions; Earth’s most diverse marine biome

    • Coral are tiny animals that secrete a layer of limestone (calcium carbonate) to form an external skeleton; the animals living inside draw in plankton and detritus for food

      • Coral Bleaching: a phenomenon in which the algae in the coral die → coral turn white (due to lower ocean pH and abnormally high water temperatures)

  • Open Ocean: deep ocean water that is located away from the shoreline where sunlight can no longer reach the ocean bottom

    • The exact depth of penetration by sunlight depends on a number of factors, including the amounts of sediment and algae suspended in the water (typically does not exceed 650 feet)

    • Photic Zone: upper layer of ocean water that receives enough sunlight to allow photosynthesis; phytoplankton produce a large amount of the plant’s oxygen and take up a large amount of carbon dioxide here

    • Photic Zone: deeper layer of water that lacks sufficient sunlight for photosynthesis

    • the ocean floor is the benthic zone (same as the one in lakes and ponds)

    • Chemosynthesis: bacteria uses this process to generate energy using methane and hydrogen sulfide 

• Habitat: an area where a particular species lives in nature; subset of a biome

• Carbon Cycle: the movement of carbon around the biosphere among reservoir sources and sinks 

  • Photosynthesis: Plants absorb carbon dioxide (CO2) from the atmosphere during photosynthesis, converting it into organic carbon compounds like glucose and releasing oxygen as a byproduct.

  • Respiration: Both plants and animals engage in cellular respiration, where organic carbon compounds are broken down to release energy, producing CO2 as a byproduct, which returns to the atmosphere.

  • Exchange: Carbon is exchanged between the atmosphere, plants, and soil through various processes such as photosynthesis, respiration, and decomposition.

  • Sedimentation: When marine organisms die, their remains sink to the ocean floor, where they accumulate as sediment over time. This process sequesters carbon in the form of organic matter, contributing to the carbon cycle.

  • Burial: Over millions of years, accumulated organic matter in sediment layers can become buried deep underground. Through geological processes, this organic matter can transform into fossil fuels like coal, oil, and natural gas, locking away carbon for extended periods.

  • Extraction: Humans extract fossil fuels from underground reservoirs through processes like drilling and mining. This extraction releases carbon that has been stored underground for millions of years back into the atmosphere when these fuels are burned for energy.

  • Combustion: When fossil fuels are burned for energy, whether for transportation, electricity generation, or industrial processes, carbon stored within them is rapidly released into the atmosphere in the form of carbon dioxide (CO2) and other greenhouse gasses.

  • Human Impacts:

    • Greenhouse Gasses: absorb heat and re-emit in all directions → planet gets warmer

    • Global Warming: the increase in global temperatures due to humans producing more greenhouse gasses 

• Limiting Nutrient: a nutrient required for the growth of an organism but available in a lower quantity than other nutrients; constraints the growth of plants and algae

• Nitrogen Cycle: movement of nitrogen around the biosphere among reservoir sources and sinks

  • Nitrification: Soil bacteria further convert ammonium ions (NH4+) into nitrites (NO2-) and then into nitrates (NO3-), through oxidation processes known as nitrification. Nitrates are more readily absorbed by plants and used in biological processes.

  • Assimilation: Plants and other organisms assimilate nitrogen from the soil in the form of nitrates or ammonium ions to build proteins, nucleic acids, and other essential biomolecules. Animals obtain nitrogen by consuming plants or other animals.

  • Mineralization: When plants and animals die, decomposers break down their organic matter, releasing nitrogen compounds back into the soil as ammonium ions. This process is called mineralization or ammonification.

  • Denitrification: In oxygen-deprived environments, such as waterlogged soils or sediments, certain bacteria carry out denitrification. They convert nitrates (NO3-) back into atmospheric nitrogen (N2) or nitrous oxide (N2O), releasing it into the atmosphere.

  • Human Impacts (Leaching): Human activities, particularly agriculture, can disrupt the nitrogen cycle. Excessive use of nitrogen-based fertilizers can lead to runoff or leaching of nitrates into water bodies. This excess nitrogen can cause eutrophication, where excessive nutrient levels stimulate algal growth, leading to oxygen depletion and harming aquatic ecosystems.

• Phosphorus Cycle: the movement of phosphorus around the biosphere among sources and sinks

  • Weathering: Phosphorus is released from rocks through weathering processes over geological time scales. Rain and erosion gradually break down phosphorus-containing minerals, releasing phosphates (PO4^3-) into the soil and water.

  • Assimilation: Plants absorb phosphates from the soil through their roots and incorporate them into organic compounds such as DNA, RNA, and ATP. Animals obtain phosphorus by consuming plants or other animals.

  • Mineralization: When plants and animals die, decomposers break down their organic matter, releasing phosphorus back into the soil as phosphate ions. This process is similar to nitrogen mineralization.

  • Sedimentation: Phosphorus can become bound to soil particles and sediment, particularly in aquatic environments. Over time, these sediments accumulate, sequestering phosphorus and forming phosphate-rich deposits.

  • Geologic Uplift: Geological processes, such as tectonic movements and volcanic eruptions, can uplift phosphate-rich sediments from the ocean floor, exposing them to the surface and restarting the phosphorus cycle over long time scales.

  • Human Impacts (Algal Bloom, Hypoxic Dead Zones): Excessive phosphorus runoff from human activities, such as agriculture (fertilizers), sewage discharge, and industrial runoff, can lead to eutrophication in water bodies. Elevated phosphorus levels stimulate rapid algal growth, resulting in algal blooms. As  these algae die and decompose, oxygen levels in the water decrease, leading to hypoxic (low oxygen) conditions and the formation of dead zones where marine life cannot survive.

• Hydrologic Cycle: the movement of water around the biosphere among reservoir sources and sinks

  • Solar Heating: The sun's energy drives the water cycle by heating the Earth's surface, causing water bodies like oceans, lakes, and rivers to evaporate.

  • Evaporation: Water evaporates from the Earth's surface, transitioning from liquid to vapor form and rising into the atmosphere.

  • Transpiration: Plants absorb water from the soil through their roots. This water travels through the plant's tissues and evaporates from tiny openings called stomata in their leaves, contributing to the water vapor in the atmosphere.

  • Condensation: As water vapor rises into the atmosphere, it cools and condenses to form clouds. This process involves water vapor molecules coming together to form liquid droplets or ice crystals, which can eventually lead to cloud formation.

  • Precipitation: When condensation reaches a critical point, water droplets in clouds combine to form larger droplets or ice crystals, eventually becoming heavy enough to fall back to the Earth's surface as precipitation. Precipitation can take various forms, including rain, snow, sleet, or hail.

  • Infiltration: Precipitation that falls onto the Earth's surface can infiltrate into the soil, replenishing groundwater reserves. Infiltration rates depend on soil characteristics, such as porosity and permeability.

  • Plant Intake: Some of the infiltrated water is taken up by plant roots and used for various physiological processes, such as photosynthesis and transpiration.

  • Surface Runoff: Not all precipitation infiltrates into the soil. Excess water flows over the land surface as runoff, eventually reaching streams, rivers, lakes, and oceans. Surface runoff plays a crucial role in transporting water and nutrients across landscapes.

• Producers/Autotrophs: plants, algae, and some bacteria that use the Sun’s energy to produce usable forms of energy (sugars via photosynthesis)

• Cellular Respiration: a process by which cells unlock the energy of chemical compounds (opposite of photosynthesis); cells convert glucose and oxygen into energy, carbon dioxide, and water

  • Anaerobic Respiration: a process by which cells convert glucose into energy in the absence of oxygen (does not provide as much energy as aerobic respiration)

• Primary Productivity: the rate of converting solar energy into organic compounds over a period of time

  • Gross Primary Productivity (GPP): of the ecosystem is a measure of the total amount of solar energy that producers in tan ecosystems capture via photosynthesis over a given amount of time 

  • Net Primary Productivity (NPP): the energy captured by producers in an ecosystem minus the energy producers use for respiration

    • NPP = GPP - R (respiration by producers)

  • Biomass: the total mass of all living matter in a specific area

    • the NPP of an ecosystem establishes the rate at which biomass is produced over a given amount of time

    • Standing Crop: the amount of biomass present in an ecosystem at a particular time; measures the amount of energy in a system at a give time 

• Consumers/Heterotrophs: are incapable of photosynthesis and must obtain energy by consuming other organisms

  • Herbivores/Primary Consumers: eat producers (plant/algae eaters)

  • Carnivores/Secondary Consumers: eat primary consumers

    • Tertiary Consumers: eat secondary consumers

• Trophic Levels: the successive levels of organisms consuming one another

  • Food Chain: the sequence of consumption from producers through tertiary consumers 

  • Scavengers: organisms that consume dead animals

  • Detritivores: organisms that specialize in breaking down dead tissues and waste products (aka detritus) into smaller particles

  • Decomposers: these organisms break the particles down even more (fungi and bacteria) and complete the breakdown process by converting organic matter into smaller elements and molecules that can be recycled back into the ecosystem

• Ecological Efficiency: the proportion of consumed energy that can be passed from one trophic level to another

  • The 10% rule: only 10% can be converted into energy at the next higher trophic level

  • Trophic Pyramid: a representation of the distribution of biomass, numbers, or energy among trophic levels

• Food Web: a model of how energy and matter (carbon, nitrogen, and phosphorus) move through two or more interconnected food chains

  • Positive Feedback Loop: Amplifies or increases a change in a system, leading to self-reinforcing or accelerating effects

  • Negative Feedback Loop: Counteracts or reduces a change in a system, maintaining stability or equilibrium

Unit 2: The Living World: Biodiversity

• Genetic Diversity: a measure of the genetic variation among individuals in a population

  • Large populations typically have high amounts of variation in their genetic composition 

  • Population Bottleneck: when a large population declines in number, the amount of genetic diversity carried by the surviving individuals is greatly reduced

  • High genetic diversity benefits the long-term persistence of populations because they are better able to respond to environmental change 

•  Species Diversity: indicates the number of species in a region or in a particular ecosystem

• Habitat Diversity: the variety of habitats that exist in a given ecosystem

  • Specialists: organisms that only live under a narrow range of biotic or abiotic conditions 

  • Generalists: organisms that can live under a wide range of biotic or abiotic conditions

    • The loss of a single habitat type generally leads to the loss of the specialists species, but not the loss of the generalists (they can live in other habitats)

• Ecosystem Diversity: the variety of ecosystems in a given region

  • Species Richness: the number of different species in a given area of an ecosystem

  • Species Evenness: the relative proportion of individuals within the different species in a given area

    • An ecosystem has high species evenness if its species are all represented by similar numbers of individuals 

    • An ecosystem has low species evenness if one species is represented by many individuals whereas other species are represented by only a few individuals 

• Ecosystem Services: the processes by which life-supporting resources like clean water, timber, fisheries, and agricultural crops are produced; maybe benefit us indirectly by providing a diversity of conditions, nutrients, and species (healthier ecosystem)

  • Regulating Services: the ability of an ecosystem to be resilient, ensuring that it will continue to exist in its current state in the face of environmental change; ensures it can continue to benefit humans

  • Support Systems: Foundational processes within ecosystems that sustain life, such as soil formation, nutrient cycling, water purification, and pollination

  • Cultural Services: Non-material benefits provided by ecosystems, including recreational opportunities, aesthetic values, spiritual and cultural significance, and educational values, enhancing human well-being and cultural identity

  • Aquaculture: the capture of wild animals from the ocean and the farming of fish, shellfish, and seaweed

• Provisions: goods produced by ecosystems that humans can use directly 

  • Examples: lumber, food crops, medicinal plants, natural rubber, and furs

• Island Biogeography: the study of how species are distributed and interacting on islands

  • Species-Area Curve: a description of how the number of species on an island increases with the area of the island 

• Ecological Tolerance: the suite of abiotic conditions under which a species can survive, grow, and reproduce (aka the fundamental niche)

  • Realized Niche: the range of abiotic and biotic conditions under which a species actually lives 

  • Geographic Range: the areas of the world in which the species lives

• Mass Extinction: large numbers of species went extinct over relatively short periods of time (we are in the sixth right now)

• Disruptions:

  • Periodic Disruptions: occur regularly; cycles of day and night or the daily and monthly cycle 

  • Episodic Disruptions: occur somewhat regularly

  • Random Disruptions: no regular pattern (volcanoes and hurricanes)

  • Resistance: a measure of how much a disruption can affect the flows of energy and matter

  • Resilience: the rate at which an ecosystem returns to its original state after a disruption

  • Intermediate Disturbance Hypothesis: ecosystems experiencing intermediate levels of disturbance will favor a higher diversity of species than those with high or low disturbance levels

• Evolution: a change in the genetic composition of a population over time

  • Microevolution: the evolution at the population level

  • Macroevolution: the larger categories of organisms into which species are organized 

  • Evolution by Artificial Selection: when humans determine which individuals to breed (typically with a preconceived set of traits in mind); typically for aesthetics

  • Evolution by Natural Selection: the environment determines which individuals survive and reproduce

    • Favors an individual's fitness (ability to survive and reproduce)

      • Adaptations (a trait that improves an individual’s fitness)

  • Evolution by Random Processes: mutation, gene flow, genetic drift, bottleneck effects,  and founder effects

    • Mutation: random changes or alterations in the genetic material (DNA) of an organism, introducing genetic variation into populations over time

    • Gene Flow: the process by which individuals move from one population to another → alters the genetic composition of both populations 

    • Genetic Drift: a change in the genetic composition of a population over time as a result of random mating (nonadaptive, random process)

    • Bottleneck Effect: a drastic reduction in the size of a population that reduces genetic variation; changes a population genetic composition

    • Founder Effect: Evolutionary process occurring when a small group of individuals establishes a new population, leading to a loss of genetic diversity due to the limited genetic variation present in the founding population, which can result in distinct genetic characteristics in subsequent generations

• Speciation: when a group within a species separates from other members of its species and develops its own unique characteristics

  • Allopatric Speciation: the process of speciation that occurs with geographic isolation

    • Geographic isolation can occur when a subset of individuals from a larger population colonizes a new area of habitat that is physically separated from the larger population 

  • Sympatric Speciation: the evolution of one species into two species without any geographic isolation; usually happens through polyploidy (when the numer of chromosome sets increases to 3-6)

• Genetically Modified Organisms (GMOs): scientists insert genes into other species of plants, animals, or microbes

  • When a GMO reproduces, it passes on the inserted gene to its offspring

• Ecological Succession: the predictable replacement of one group of species by another group of species over time

  • Primary Succession: when succession begins with bare rock and no soil

    • Pioneer Species: organisms that can survive with little or no soil; algae, lichens, and mosses

  • Secondary Succession: occurs in areas that have been disturbed but have not lost their soil; follows an event (like forest fires, or hurricanes) that removes vegetation but leaves the soil intact

  • Climax Community: succession’s final stage

• Keystone Species: a species that is not very abundant but has large effects on an ecological community

• Indicator Species: a species that demonstrates a particular characteristic of an ecosystem

• Endemic Species: species that live in a very small area of the world and nowhere else 

  • Biodiversity Hotspots: isolated areas that are home to many endemic species, that they contain a high proportion of all the species on Earth

Unit 3: Populations

• Population/Intrinsic Growth Rate: the number of offspring an individual can produce in a given time period, minus the deaths of the individual or its offspring during that same period

  • K-Selected Species: species with a low intrinsic growth rate that causes the population to increase slowly until it reaches the carrying capacity of the environment

    • Carrying Capacity: the limit to individuals that can be supported by an existing habitat or ecosystem (denoted as K)

  • r-Selected Species: species with a high intrinsic growth rate and their populations typically increase rapidly; reproduce often and produce large numbers of offspring 

    • Overshoot: once a population exceeds its carrying capacity

    • Dieback/Die-off: the sharp reduction in the population of a species when its numbers exceed the carrying capacity of its habitat

  • 

• Biotic Potential; with ideal conditions and unlimited resources available, every population has a particular maximum potential for growth

• Survivorship Curves: graphs that represent the distinct patterns of species survival as a function of age

  • Type 1 Survivorship Curve: high survival throughout most of the lifespan, but then individuals start to die in large numbers as they approach old age (K-selected species; elephants, whales, and humans)

  • Type 2 Survivorship Curve: relatively constant decline in survivorship throughout most of the life span (K-selected species; chipmunks, squirrels, birds of prey)

  • Type 3 Survivorship Curve: low survivorship (high death rate) early in life with few individuals reaching adulthood; those that make adulthood live for a while (r-selected; mosquitos, many fish, dandelions, many frogs)

• Density Dependent Factors: factors that influence an individual’s probability of survival and reproduction in a manner that depends on the size of the population

  • Limiting Resource: a resource that a population cannot live without and that occurs in quantities lower than population would require to increase in size 

• Density Independent Factors: those that have the same effect on an individual's probability of survival and reproduction at any population size

• Population Growth Models: mathematical equations that can be used to predict population size at any moment in time

  • Fecundity: ability to produce an abundance of offspring

  • Exponential Growth Model: a model that estimates a population’s future size after a given period of time based on the biotic potential and the number of reproducing individuals currently in the population

  • J-Shaped Curve: exponential growth; represents the change in a growing population overtime 

• Logistical Growth Model: describes a population whose growth is initially exponential but slows as the population approaches the carrying capacity of the environment

  • S-Shaped Curve: logistical growth

• Demography: the study of human populations and population trends; a scientist in this field (aka a demographer)

• Immigration: the movement of people into a country or region from another country or region 

• Emigration: the movement of people out of a country or region 

  • Crude Birth Rate (CBR): the number of births per 1,000 individuals per year 

  • Crude Death Rate (CDR): the number of deaths per 1,000 individuals per year 

    • CBR - CDR / 10 x 100

  • Net Migration Rate: the difference between immigration and emigration in a given year per 1,000 people in a country 

    • (CBR + immigration) - (CDR + emigration) / 10

• Life Expectancy: the average number of years that an infant born in a particular year in a particular country can be expected to live 

  • Infant Mortality Rate: the number of deaths of children under 1 year of age per 1,000 live births 

  • Child Mortality Rate: the number of deaths of children under age 5 per 1,000 live births 

• Environmental Justice: the disproportionate exposure to environmental hazards experienced by people of color, recent immigrants, and people of lower socioeconomic backgrounds

• Age Structure Diagram: a visual representation of the number of individuals within specific age groups for a country, typically expressed separately for males and females

  • Population Pyramid: typical for developing countries (Venezuela, South Sudan, and Nigeria)

    • Developing Countries: relatively high levels of industrialization and income; tend to have more children in the workforce 

  • Population Momentum: continued population growth after growth reduction measures have been implemented

• Total Fertility Rate (TFR): an estimate of the average number of children that each woken in a population will bear throughout her childbearing years 

  • Family Planning: regulation of the number or spacing of offspring through the use of birth control 

  • Replacement-Level Fertility: the TFR required to offset the average number of deaths in a population in order to maintain the current population size, assuming there is no net migration

• Doubling Time: the number of years it takes for a population to double 

  • Rule of 70: dividing the number 70 by the percentage population growth rate we can determine a population's doubling time

    • Doubling time (years) = 70 / growth rate %

• Theory of Demographic Transition: a country moves from higher to lower birth and death rates as development occurs and that country moves from a preindustrial to an industrialized economic system 

• IPAT Equation: impact = population x affluence x technology

Unit 4: Earth Systems and Resource

• Core: the innermost zone of the Earth’s interior; dense mass made of nickel and iron

• Mantle: above the core; comprised of 3 layers:

  • Magma: molten rock in the innermost portion of the mantle

  • Asthenosphere: in the upper mantle composed of semi-molten, flexible rock, and then the solid upper mantle

• Lithosphere: the solid upper mantle and the crust

  • Plate Tectonics: Earth’s lithosphere is divided into plates, most of which are in constant motion and create mountain ranges and canyons (on land and in the oceans)

    • Earthquake: sudden movement of Earth’s crust caused by a release of potential energy from the movement of tectonic plates

    • Hot Spots: places where molten material from the antle reaches the lithosphere

      • Volcano: when a plate moves over a geologic hotspot, heat from the rising mantle plume melts the crust

    • Tsunami: a series of waves in the ocean caused by seismic activity in the ocean or an undersea volcano that causes massive displacement of water

    • Plate Boundaries:

      • Divergent Boundary: rising magma forms new oceanic crust on the seafloor at the boundaries between those plates; causes seafloor spreading (rising magma forms new oceanic crust on the seafloor at the boundaries between those plates)

      • Convergent Boundaries: as one plate moves toward another plate and collides

        • Subduction: the process in which the edge of an oceanic plate moves downward beneath the continental plate and is pushed toward the center of Earth

          • Island Arc: A chain of islands formed by volcanoes as a result of two tectonic plates coming together and experiencing subduction

        • Collision Zone: an area where two continental plates are pushed together and the colliding forces push up the crust to form a mountain range 

      • Transform Boundary: locations where plates move sideways past each other

        • Fault: a fracture in the rock caused by movement in Earth’s crust 

• Igneous Rocks: form directly from magma; classified by their chemical composition as basaltic or granitic

• Sedimentary Rocks: form when sediments such as muds, sands, or gravels are compressed by overlying sediments

• Metamorphic Rocks: form when sedimentary rocks, igneous rocks, or other metamorphic rocks are subjected to high temperatures and pressures 

• Rock Cycle: governs the constant formation, alteration, and destruction of rock material that results from tectonics, weathering, and erosion, among other process (slowest cycle)

• Physical Weathering: the mechanical breakdown of rocks and minerals; can be caused by water, wind, or variations in temperature 

• Chemical Weathering: the breakdown of rocks and minerals by chemical reactions, the dissolving of chemical elements from rocks (or both); releases essential nutrients from rocks making them available for use by plants and other organisms

  • Acid Precipitation/Rain: precipitation high in sulfuric and nitric acids

• Erosion: the physical removal of rock fragments from a landscape or ecosystem; due to wind, water, ice, and living organisms

• Porosity: the differences in particle size affecting the size of the air spaces between particles 

  • Water Holding Capacity: the amount of water a soil can hold against the draining force of gravity

  • Permeability: the ability of water to move through the soil; soils with high water holding capacity have low permeability

• Cation Exchange Capacity (CEC)/Nutrient Holding Capacity: the ability of a particular soil to absorb and release cations

  • Base Saturation: the proportion of soil bases to soil acids in a percentage

• Watersheds: all the land in an area that drains into a particular stream, river, lake, or wetland

• Insolation: incoming solar radiation, which is the main source of energy on Earth

• Albedo: the percentage of incoming sunlight that is reflected from a surface

• Layers of the Atmosphere:

  • Troposphere: closest to Earth’s surface; densest layer of the atmosphere and is the layer where most of the atmosphere’s nitrogen, oxygen, and water vapor occur

    • This layer is where weather occurs

  • Stratosphere: above the troposphere; less dense and has an ozone layer that absorbs most of the Sun’s ultraviolet-B and all of the ultraviolet-C radiation

    • Ozone: a pale blue gas composed of molecules made up of three oxygen atoms

  • Mesosphere: where most meteors burn up in the atmosphere

  • Thermosphere: blocks harmful X-ray radiation and some UV radiation from reaching our planet

  • Exosphere: outmost layer; where satellites orbit

• Saturation Point: the maximum amount of water vapor that can be in the air at a given temperature 

• Adiabatic Cooling: the cooling effect of reduced pressure on air as it rises in the atmosphere and expands

• Adiabatic Heating: the heating effect of increased pressure on air as it sinks toward the surface of Earth and decrease in volume

• Latent Heat Release: the release of energy when water vapor in the atmosphere condenses into liquid water

• Atmospheric Convection Currents: global patterns of air movement that are initiated by the unequal heating of Earth, with regions near the equator receives more solar radiation than regions near the poles

• Hadley Cells: convection currents that cycle between the equator and approximately 30°N and 30°S

  • Intertropical Convergence Zone (ITCZ): when the latitude that receives the most intense sunlight causes the ascending branches of two Hadley cells to converge

  • Polar Cells: a convection current in the atmosphere, formed by air that rises at 60°N and 60°S and sinks at the poles, 90°N and 90°S

  • Ferrell Cells: a convection current in the atmosphere that lies between Hadley and Polar cells

• Coriolis Effect: the deflection of an object’s path due to the rotation of Earth

• Gyres: a large-scale pattern of water circulation that moves clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere

• Upwelling: the upward movement of ocean water toward the surface as a result of diverging currents

• Thermohaline Circulation: an oceanic circulation pattern that drives the mixing of surface and deep water

• Rain Shadow: a region with dry conditions found on the leeward side of a mountain range as a result of humid winds from the ocean causing precipitation on the windward side

• El Niño-Southern Oscillation (ENSO): a reversal of wind and water currents in the South Pacific 

  • La Niña: Following an El Niño event, trade winds in the South Pacific reverse strongly, causing regions that were hot and dry to become cooler and wetter

Unit 5: Land and Water Use

• Tragedy of the Commons: the tendency of a shared, limited resource to become depleted if it is not regulated in some way

• Externality: the cost or benefit of a good or service that is not included in the purchase price of that good or service, or otherwise accounted for

• Rangelands: dry, open grasslands primarily used for grazing cattle; semiarid ecosystems and susceptible to fires and other environmental disturbances

  • When overused, rangelands are very susceptible to lose biodiversity

• Forests: land areas dominated by trees and other woody vegetation and sometimes used for commercial logging; ¾ of the forests used for commercial timber operations in the US are privately owned

  • 

  • Tree Plantations: a large area typically planted with a single fast-growing tree species 

• Endangered Species Act: a 1973 US law designed to protect plant and animal species that are threatened with extinction, and the habitats that support those species

• Subsistence Farming: farming for consumption by the farming family and maybe a few neighbors 

• Industrial Agriculture/Agribusiness: agriculture that applies the techniques of mechanization and standardization to the production of food

• Green Revolution: a shift in agricultural practices in the twentieth century that included new management techniques and mechanization, as well as fertilization, irrigation, and improved crop varieties → increased food output

  • Economies of Scale: the observation that average costs of production fall as output increases

  • Organic Fertilizer: composed of organic matter from plants and animals (typically animal manure and/or crop residues that decomposed)

  • Synthetic/Inorganic Fertilizer: produced commercially, normally with the use of fossil fuels

• Waterlogging: a form of soil degradation that occurs when soil remains under water for prolonged periods, impairs root growth because roots cannot obtain oxygen

• Salinization: occurs when the small amounts of salts in irrigation water become highly concentrated on the soil surface through evaporation

• Pesticides: substances that, either natural or synthetic, kill or control organisms that people consider pests

  • Insecticides: target species of insects and other invertebrates that consume crops

  • Herbicides: target plant species that compete with crops

  • Broad-Spectrum Pesticides: they kill many types of pests

    • Selective/Narrow-Spectrum Pesticide: targets a narrow range of organisms

  • Fungicide: A pesticide that specifically targets fungi (the plural of fungus).

  • Rodenticide: A pesticide that specifically targets rodents.

  • Persistent pesticides: Pesticides that remain in the environment for years to decades.

  • Nonpersistent pesticides: Pesticides that break down relatively rapidly, usually in weeks to months, and have fewer long-term effects but because they must be applied more often their overall environmental impact is not always lower than that of persistent pesticides.

  • Integrated pest management (IPM): An agricultural practice that uses a variety of techniques to minimize pesticide inputs.

  • Pesticide resistance: A trait possessed by certain individuals that are exposed to a pesticide and survive

• Monocropping: an agricultural method that utilizes large plantings of a single species or variety

• Energy Subsidy: the fossil fuel energy and human energy input per calorie of food produced

• Plowing: the process of digging deep into the soil and turning it over

• Tilling: the preparation of soil through a variety of activities including plowing but also including stirring, digging, and cultivating 

• Slash-and-Burn/Shifting Agriculture: an agricultural method in which land is cleared and farmed for only a few years until the soil is depleted of nutrients

• Aquifer: pore spaces found with permeable layers of rock and sediment underneath the soil that store groundwater 

  • Unconfined Aquifer: porous rock covered by soil

  • Confined Aquifer: surrounded by a layer of impermeable rock or clay, which impedes water flow to or from the aquifer

    • Artesian Well: a well created by drilling a hole into a confined aquifer

  • Water Table: the uppermost layer at which the groundwater in a given area fully saturates the rock or soil

  • Groundwater Recharge: the process by which from precipitation percolates through the soil into groundwater

  • Springs: water that naturally percolates up to the surface

• Water Footprint: total daily per capita use of fresh water for a country or the world

• Furrow Irrigation: a form of irrigation where the farmer digs trenches (furrows) along crop rows and fills them with water

• Flood Irrigation: A form of irrigation where an entire field is flooded with water

• Spray irrigation: A form of irrigation where water is pumped into an apparatus that contains a series of spray nozzles.

• Drip irrigation: A form of irrigation where a slowly dripping hose on the ground or buried beneath the soil delivers water directly to the plant roots.

• Cone of Depression: An area surrounding a well that does not contain groundwater.

• Concentrated animal feeding operation (CAFO): A large indoor or outdoor structure designed for maximum occupancy of animals and maximum output of meat

  • Manure lagoon: Human-made pond lined with rubber built to handle large quantities of manure produced by livestock.

• Free range grazing: Allowing animals to graze outdoors on grass for most or all of their lifecycle.

  • Nomadic grazing: The feeding of herds of animals by moving them to seasonally productive feeding grounds, often over long distances.

  • Overgrazing: Excessive grazing that can reduce or remove vegetation and erode and compact the soil.

  • Desertification: Transformation of arable, productive, low-precipitation land to desert or unproductive land due to climate change or destructive land use such as overgrazing and logging.

• Fishery: A commercially harvestable population of fish within a particular ecological region.

  • Fishery collapse: The decline of a fish population by 90 percent or more

  • Bycatch: The unintentional catch of nontarget species while fishing.

• Crustal abundance: The average concentration of an element in Earth’s crust.

  • Ore: A concentrated accumulation of minerals from which economically valuable materials can be extracted.

  • Metal: An element with properties that allow it to conduct electricity and heat energy and to perform other important functions.

  • Reserve: In resource management, the known quantity of a resource that can be economically recovered.

  • Strip mining: The removal of overlying vegetation and “strips” of soil and rock to expose underlying ore.

  • Mine tailings: Unwanted waste material created during mining including mineral and other rock residues that are left behind after the desired metals are removed from the ore.

  • Open-pit mining: A mining technique that creates a large visible pit or hole in the ground.

  • Mountaintop removal: A mining technique in which the entire top of a mountain is removed with explosives.

  • Placer mining: The process of looking for minerals, metals, and precious stones in river sediments.

  • Subsurface mining: Mining techniques used when the desired resource is more than 100 m (328 feet) below the surface of Earth.

• Urbanization: The process of making an area more urban, which means increasing the density of people per unit area of land.

  • Urban area: An area that contains more than 386 people per square kilometer (1,000 people per square mile).

  • Suburbs: Areas that surround metropolitan centers.

  • Exurbs: Similar to suburbs, but are not connected to any central city.

  • Impervious surface: Pavement or other surfaces that do not allow water penetration.

  • Saltwater intrusion: An infiltration of salt water in an area where groundwater pressure has been reduced as a result of a cone of depression from extensive pumping of wells.

  • Urban sprawl: Urbanized areas that spread into rural areas.

  • Urban blight: A lack of support for and deterioration of urban communities.

  • Sense of place: The feeling that an area has a distinct and meaningful character.

  • Urban runoff: Runoff, water that does not evapotranspire or infiltrate the soil, that occurs in an urban area.

• Ecological footprint: A measure of the area of land and water an individual, population, or activity requires to produce all the resources it consumes and to process the waste it generates.

• Carbon footprint: A measure of the total carbon dioxide and other greenhouse gases emissions from the activities, both direct and indirect, of a person, country, or other entity.

  • Sustainability: Being able to use a resource or engage in an activity now without jeopardizing the ability of future generations to engage in similar activities later.

  • Sustainable development: Development that balances current human well-being and economic advancement with resource management for the benefit of future generations.

  • Maximum sustainable yield (MSY): The largest quantity of a renewable resource that can be harvested indefinitely.

• Environmental indicators: Describe the current state of an environmental system or the Earth.

  • Biodiversity, Food production, Average global surface temperature and carbon dioxide concentrations in the atmosphere, Human population, and Resource depletion

• Farming Methods:

  • Crop rotation: A crop-planting strategy in which different types of crop species are planted from season to season or year to year on the same plot of land.

  • Intercropping: An agricultural technique that calls for physical spacing of different crops growing at the same time, in close proximity to one another, to promote biological interaction.

  • Biocontrol: A shortened term for biological control, it uses biological organisms to control agricultural pests.

  • Natural predators: Predators that occur naturally in the environment.

  • Sustainable agriculture: Fulfills the need for food and fiber while enhancing the quality of the soil, minimizing the use of nonrenewable resources, and allowing economic viability for the farmer.

  • Soil conservation: The prevention of soil erosion while simultaneously increasing soil depth and increasing the nutrient content and organic matter content of the soil.

  • Agroforestry: An agricultural technique in which trees and vegetables are intercropped.

  • Windbreaks: An agricultural technique that literally plants tall objects that “break” the wind and prevent soil erosion.

  • Strip cropping: An agricultural method of planting crops with different spacing and rooting characteristics in alternating sets of rows to prevent soil erosion.

  • Contour plowing: Plowing and harvesting parallel to the topographic contours of the land.

  • Terracing: An agricultural technique where farms shape sloping land into step-like terraces that are flat.

  • Perennial plants: Plants that live for multiple years and do not need to be replanted at the beginning of each growing season.

  • No-till agriculture: an agricultural method used in fields of annual crops where farmers do not till or plow the soil between seasons.

  • Green manure: Plant material deliberately grown in a field with the intention of plowing it under at the end of the season.

  • Limestone: A calcium carbonate sedimentary rock that has been ground up or crushed for easy application as a fertilizer.

  • Rotational grazing: The rotation of farm animals to different pastures and fields to prevent overgrazing.

  • Organic agriculture: The production of crops in a way that sustains or improves the soil, without the use of synthetic pesticides or fertilizers.

• Delaney Clause: A clause in the Food, Drug, and Cosmetic Act designed to prevent potentially harmful cancer-causing food ingredients.

• Reforestation: The natural or intentional restocking of trees after clear-cutting to repopulate the forest, reduce erosion, and begin the process of removing carbon dioxide from the atmosphere.

• Sustainable forestry: A methodology for managing forests so they provide wood while also providing clean water, maximum biodiversity, and maximum carbon sequestration in both trees and soil.

• Prescribed burn: When a fire is deliberately set under controlled conditions, thereby decreasing the accumulation of dead biomass on the forest floor.

Unit 6: Energy Resources and Consumption

• Nonrenewable energy resource: An energy source with a finite supply, primarily fossil fuels and nuclear fuels.

  • Fossil fuels: Fuels derived from biological material that became fossilized millions of years ago.

    • Fossil fuel combustion: The chemical reaction between any fossil fuel and oxygen resulting in the production of carbon dioxide, water, and the release of energy.

  • Nuclear power: Electricity generated from the nuclear energy contained in nuclear fuel.

    • Radioactivity: The emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei.

    • Fission: A nuclear reaction in which a neutron strikes a relatively large atomic nucleus, which then splits into two or more parts, releasing additional neutrons and energy in the form of heat.

    • Fuel rod: A cylindrical tube that encloses nuclear fuel within a nuclear reactor.

    • Control rod: A cylindrical device inserted between the fuel rods in a nuclear reactor to absorb excess neutrons and slow or stop the fission reaction.

    • Radioactive decay: When a parent radioactive isotope emits alpha or beta particles or gamma rays.

    • Half-life: The time it takes for one-half of the original radioactive parent atoms to decay

    • Radioactive waste: Nuclear fuel that can no longer produce enough heat to be useful in a power plant but continues to emit radioactivity.

    • Becquerel (Bq): A measurement of the rate at which a sample of radioactive material decays; 1 Bq is equal to the decay of one atom per second.

    • Curie: A unit of measure for radiation, a curie is 37 billion decays per second.

    • Nuclear Accidents: Three Mile Island, Chernobyl, and Fukusima

  • Capacity: The maximum electrical output of something such as a power plant.

  • Capacity factor: The fraction of time a power plant operates during a year.

• Crude oil: A mixture of hydrocarbons such as oil, gasoline, kerosene as well as water and sulfur that exists in a liquid state underground, and when brought to the surface.

  • Tar sands: Slow-flowing, viscous deposits of bitumen or asphalt, mixed with sand, water, and clay; also known as oil sands.

  • Hubbert curve: A graph that represents oil use and projects both when world oil production will reach a maximum and when world oil will be depleted.

  • Peak oil: The point at which oil extraction and use would increase steadily until roughly half the supply had been used up.

  • Fracking: Short for hydraulic fracturing, a method of oil and gas extraction that uses high-pressure fluids to force open existing cracks in rocks deep underground.

• Renewable energy resources: Sources of energy that are infinite.

• Potentially renewable: An energy source that can be regenerated indefinitely as long as it is not overharvested.

• Nondepletable: An energy source that cannot be used up.

• Commercial energy sources: Energy sources that are bought and sold, such as coal, oil, and natural gas.

• Subsistence energy sources: Energy sources gathered by individuals for their own immediate needs including straw, sticks, and animal dung.

• Energy intensity: The energy use per unit of gross domestic product (GDP)

• Energy conservation: Methods for finding and implementing ways to use less energy.

• Energy efficiency: The ratio of the amount of energy expended in the form you want to the total amount of energy that is introduced into the system.

• Energy return on energy investment (EROEI): The amount of energy we get out of an energy source for every unit of energy expended on its production.

  • EROEI: energy obtained from the fuel/ energy invested to obtain the fuel

• Biofuel: A liquid fuel such as ethanol or biodiesel created from processed or refined biomass.

  • Biomass: Biological material that has mass.

    • Charcoal: Woody material that has been heated in the absence of oxygen so that water and some volatile compounds are driven off.

    • Ethanol: Alcohol made by converting starches and sugars from plant material into alcohol and CO2

    • Biodiesel: A diesel substitute produced by extracting and chemically altering oil from plants.

• Modern carbon: Carbon in biomass that was recently in the atmosphere.

• Fossil carbon: Old carbon contained in fossil fuels.

• Carbon neutral: an activity that does not change atmospheric CO2 concentrations

• Peat: A precursor to coal, made up of partly decomposed organic material, including mosses

• Coal: A solid fuel formed primarily from the remains of trees, ferns, and other plant materials that were preserved 280 million to 360 million years ago

  • Lignite: A brown coal that is a soft sedimentary rock that sometimes shows traces of plant structure; it typically contains 60 to 70 percent carbon.

  • Bituminous coal: A black or dark brown coal that contains bitumen, also known as asphalt. It typically contains up to 80 percent carbon.

  • Anthracite: Also known as hard coal, it contains greater than 90 percent carbon. It has the highest quantity of energy per volume of coal and the fewest impurities.

• Natural gas: A relatively clean fossil fuel containing 80 to 95 percent methane (CH4) and 5 to 20 percent ethane, propane, and butane.

  • Combined cycle: A feature in some natural gas–fired power plants that uses both a steam turbine to generate electricity and a separate turbine that is powered by the exhaust gasses from natural gas combustion to turn another turbine to generate electricity.

• Energy carrier: An energy source such as electricity that can move and deliver energy in a convenient, usable form to end users.

• Cogeneration: The use of a fuel to both generate electricity and deliver heat to a building or industrial process. Also known as combined heat and power.

• Volatile organic compounds (VOCs): A type of organic compound air pollutants that evaporate at typical atmospheric temperatures.

• Turbine: A device that can be turned by water, steam, or wind to produce power such as electricity.

• Electrical grid: A network of interconnected transmission lines.

• Energy quality: The ease with which an energy source can be used to do work.

• What is Released? 

  • Particulates (Particulate matter): Solid or liquid particles suspended in the air. Also known as soot.

  • Carbon monoxide: A colorless, odorless gas that is formed during incomplete combustion of most materials.

  • Nitrogen oxides: A by-product of combustion of any fuel in the atmosphere (which contains 78 percent nitrogen).

  • Carbon dioxide: A by-product of all combustion, carbon dioxide from biofuels contains modern carbon from woody material, rather than fossil carbon from fossil fuels.

• Passive solar: A use of energy from the Sun that takes advantage of solar radiation without active technology.

  • Active solar energy: A use of technology that captures and stores the energy of sunlight with electrical equipment and devices.

  • Photovoltaic solar cells: A use of energy from the Sun as light, not heat, and converting it directly into electricity.

  • Passive solar design: Construction technique designed to take advantage of solar radiation without active technology.

• Hydroelectricity: Electricity generated by the kinetic energy of moving water.

  • Water impoundment: The storage of water in a reservoir behind a dam.

  • Run-of-the-river: Hydroelectricity generation in which water is retained behind a low, small dam or no dam.

  • Tidal energy: Energy that comes from the movement of water driven by the gravitational pull of the Moon.

• Siltation: Sediments from moving water that accumulate on the bottom of a reservoir.

• Geothermal energy: Heat energy that comes from the natural radioactive decay of elements deep within Earth.

  • Ground source heat pump: A technology that transfers heat from the ground to a building.

  • Fuel cell: An electrical-chemical device that converts fuel, such as hydrogen, into an electrical current.

  • Electrolysis: The application of an electric current to water molecules to split them into hydrogen and oxygen.

• Wind energy: Energy generated from the kinetic energy of moving air.

  • Wind turbine: A turbine that converts the kinetic energy of moving air into electricity.

• Phantom loads: Electrical demand by a device that draws electrical current, even when it is turned off.

  • Peak demand: The greatest quantity of energy used at any one time.

• Thermal mass: A property of a building material that allows it to maintain heat or cold.

• Smart grid: An efficient, self-regulating electricity distribution network that accepts any source of electricity and distributes it automatically to end users.

Unit 7: Atmospheric Pollution

• Air pollution: The introduction of chemicals, particulate matter, or microorganisms into the atmosphere at concentrations high enough to harm plants, animals, and materials such as buildings, or to alter ecosystems.

  • Sulfur dioxide (SO2): A corrosive gas that comes primarily from combustion of fuels such as coal and oil, including diesel fuel from trucks.

  • Haze: Reduced visibility.

  • Photochemical oxidant: A class of air pollutants formed as a result of sunlight acting on chemical compounds such as nitrogen oxides and sulfur dioxide.

  • Smog: A type of air pollution that is a mixture of oxidants and particulate matter.

    • Photochemical smog: Smog that is dominated by oxidants such as ozone. Also known as Los Angeles–type smog; brown smog.

    • Sulfurous smog: Smog dominated by sulfur dioxide, sulfate compounds, and particulate matter. Also known as London-type smog; gray smog; industrial smog.

  • Lead (Pb): A trace metal that occurs naturally in rocks and soils, is present in small concentrations in coal and oil and is a neurotoxin.

  • Hydrocarbons: Pollutant compounds that contain carbon-hydrogen bonds, such as gasoline and other fossil fuels, lighter fluid, dry-cleaning fluid, oil-based paints, and perfumes.

• Primary pollutant: A polluting compound that comes directly out of a smokestack, exhaust pipe, or natural emission source.

• Secondary pollutant: A primary pollutant that has undergone transformation in the presence of sunlight, water, oxygen, or other compounds.

• Formaldehyde: A naturally occurring compound that is used as a preservative and as an adhesive in plywood and carpeting.

• Thermal inversion: An atmospheric condition in which a relatively warm layer of air at mid-altitude covers a layer of cold, dense air below.

• Inversion layer: The layer of warm air that traps emissions in a thermal inversion.

• Indoor air pollutants: Compounds that adversely affect the quality of air in buildings and structures.

• Asbestos: A long, thin, fibrous silicate mineral with insulating properties, which can cause cancer when inhaled.

• Radon-222: A radioactive gas that occurs naturally from the decay of uranium and is an indoor air pollutant.

• Sick building syndrome: A buildup of toxic pollutants in weatherized spaces, such as newer buildings in the developed world.

• Vapor recovery nozzle: A device that prevents VOCs from escaping into the atmosphere while a person is fueling their vehicle.

• Catalytic converter: A device that uses chemicals to convert pollutants such as nitrogen oxide and carbon monoxide to nitrogen gas and carbon dioxide.

• Scrubber: A device that uses a combination of lime and or water to separate and remove particles from industrial exhaust streams.

• Electrostatic precipitator: A device that removes particulate matter by using an electrical charge to make particles coalesce so they can be removed from the exhaust stream.

• pH: The relative strength of acids and bases in a substance. It is a logarithmic scale, meaning that each number on the scale represents a change by a factor of 10.

  • Acid: A substance that contributes hydrogen ions to a solution.

  • Base: A substance that contributes hydroxide ions to a solution.

• Noise pollution: Unwanted sound that interferes with normal activities that is loud enough to cause health issues including hearing loss.

  • decibel A scale (db(A)): A logarithmic scale that measures both the loudness of sound and the frequency.

Unit 8: Aquatic and Terrestrial Pollution

• Point source: A distinct location from which pollution is directly produced.

• Nonpoint source: A diffuse area that produced pollution.

• Homeostasis: The ability to experience relatively stable internal conditions in their bodies.

• Polychlorinated biphenyls (PCBs): A group of industrial compounds that were once used to manufacture plastics and insulate electrical transformers.

• 

• Neurotoxin: A chemical that disrupts the nervous systems of animals.

• Carcinogen: A chemical that causes cancer.

• Mutagen: A type of carcinogen that causes damage to the genetic material of a cell.

• Teratogen: A chemical that interferes with the normal development of embryos or fetuses.

• Allergen: A chemical that causes allergic reactions.

• Endocrine disruptor: A chemical that interferes with the normal functioning of hormones in an animal’s body.

• Wastewater: The water produced by livestock operations and human activities, including human sewage from toilets and gray water from bathing and washing clothes and dishes.

• Levee: An enlarged bank built up on each side of the river.

• Dikes: Structures built to prevent ocean waters from flooding adjacent land.

• Dam: A barrier that runs across a river or stream to control the flow of water.

  • Fish ladder: A stair-like structure with water flowing over them, which allows migrating fish to get around a dam.

• Reservoir: The water body created by damming a river or stream.

• Desalination: A process for obtaining fresh water by removing the salt from salt water

  • Distillation: A process of desalination in which water is boiled and the resulting steam is captured and condensed to yield pure water

  • Reverse osmosis: A process of desalination in which water is forced through a thin semi-permeable membrane at high pressure.

• Eutrophication: Excess nutrients from human activities that make their way into water-bodies; it causes nutrient pollution that alters food webs and harms water quality.

• Oxygen sag curve: The relationship of oxygen concentrations to the distance from a point source of decomposing sewage or other pollutants.

• Thermal pollution: Occurs when humans cause a substantial change in the temperature of a water body.

  • Thermal shock: A dramatic change in temperature that can kill many species.

• Persistence: The length of time a chemical remains in the environment.

  • Persistent organic pollutants (POPs): Synthetic, carbon-based molecules that break down very slowly in the environment

• Route of exposure: The way in which an individual might come into contact with an environmental hazard, such as a chemical.

• Solubility: How well a chemical dissolves in a liquid.

• Bioaccumulation: The selective absorption and concentration of a chemical within an organism over time.

• Biomagnification: The increase in chemical concentration in animal tissues as the chemical moves up the food chain.

• Solid waste: The waste produced by humans as discarded materials that are not in liquid or gas form and do not pose a toxic hazard to humans and other organisms.

  • Municipal solid waste (MSW): Solid waste collected by municipalities from households, small businesses, and institutions such as schools, prisons, municipal buildings, and hospitals.

  • Waste stream: The flow of solid waste that is recycled, incinerated, placed in a solid waste landfill, or disposed of in another way.

  • Leachate: Liquid that can contain elevated levels of pollutants as a result of having passed through the solid waste of a landfill.

  • Tipping fee: A fee charged for trucks that deliver and tip solid waste into a landfill or incinerator.

    • Incineration: The process of burning waste materials to reduce volume and mass, and sometimes to generate electricity or heat.

    • Waste-to-energy: A system in which heat generated by incineration is used as an energy source rather than released into the surrounding environment.

• Hazardous waste: Liquid, solid, gaseous, or sludge waste material that is harmful to humans, ecosystems, or materials.

  • Superfund Act: The common name for the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA); a 1980 U.S. federal act that imposes a tax on the chemical and petroleum industries, uses those funds for the cleanup of abandoned and nonoperating hazardous waste sites, and authorizes the federal government to respond directly to the release or threatened release of substances that may pose a threat to human health or the environment.

  • Brownfields: Contaminated industrial or commercial sites that may require environmental cleanup before they can be redeveloped or expanded.

• Reduce, Reuse, Recycle: A popular phrase promoting the idea of diverting materials from the waste stream. Also known as the three Rs.

  • Source reduction: An approach to waste management that seeks to cut waste by reducing the use of potential waste materials in the early stages of design and manufacture.

  • Reuse: Using a product or material that would otherwise be discarded.

  • Recycling: The process by which materials destined to become municipal solid waste (MSW) are collected and converted into raw materials that are then used to produce new objects.

    • Closed-loop recycling: Recycling a product into the same product.

    • Open-loop recycling: Recycling one product into a different product.

• Life-cycle/Cradle-to-Grave Analysis: is an important tool that examines the materials used and released throughout the lifetime of a product- from product design and procurement of raw materials through their manufacture, use, and disposal

• Integrated Waste Management: an approach to waste disposal that employs several waste reduction, management, and disposal strategies to reduce their costs and reduce the environmental impact of MSW

• Biochemical Oxygen Demand (BOD): the amount of oxygen a quantity of water uses over a period of time at a specific temperature

• Cultural Eutrophication: an increase in fertility in a body of water, the result of anthropogenic inputs of nutrients

• Fecal Coliform Bacteria: a group of microorganisms that live in the intestines of humans, other mammals, and birds that serve as an indicator species for potentially harmful microorganisms associated with contaminated sewage 

• Septic System: a relatively small and simple sewage treatment system, made up of a septic tank and a leach field, often used for homes in rural areas

  • Septic Tank: a large container that receives wastewater from a house as part of a septic system

  • Sludge: solid waste material from wastewater

  • Septage: a layer of fairly clear water found in the middle of a septic tank

  • Leach Field: a component of a septic system, made up of underground pipes laid out below the surface of the ground

• Dose-response study: a study that exposes animals or plants to different amounts of a chemical and then looks for a variety of possible responses, including mortality or changes in behavior or reproduction

• Acute study: an experiment that exposes organisms to an environmental hazard for a short duration

• Chronic study: an experiment that exposes organisms to an environmental hazard for a long duration

  • LD50: a lethal dose of a chemical that kills 50 percent of the individuals in a dose-response study

  • Sublethal Effect: the effect on an environmental hazard that does not kill an organism but which may impair an organism’s behavior, physiology, or reproduction

  • ED50: The effective dose of a chemical that causes 50 percent of the individuals in a dose-response study to display a harmful, but nonlethal, effect.

  • No-observed-effect level (NOEL): The highest concentration of a chemical that causes no lethal or sublethal effects.

• Environmental hazard: Anything in the environment that can potentially cause harm.

• Quantitative Risk Assessment: 

  • risk = prob. of being exposed to a hazard x prob. of being harmed if exposed

• Innocent-until-proven-guilty principle: A principle based on the belief that a potential hazard should not be considered an actual hazard until the scientific data definitively demonstrate that it actually causes harm.

• Precautionary principle: A principle based on the belief that when a hazard is plausible but not yet certain, we should take actions to reduce or remove the hazard.

• Stockholm Convention: A 2001 agreement among 127 nations concerning 12 chemicals to be banned, phased out, or reduced.

• REACH: A 2007 agreement among the nations of the European Union about regulation of chemicals; the acronym stands for registration, evaluation, authorization, and restriction of chemicals.

• Retrospective study: A study that monitors people who have been exposed to an environmental hazard, such as a harmful chemical, at some time in the past.

• Prospective study: A study that monitors people who might become exposed to an environmental hazard, such as a harmful chemical, at some time in the future.

• Synergistic interaction: A situation in which two risks together cause more harm than expected based on the separate effects of each risk alone.

• Disease: Any impaired function of the body with a characteristic set of symptoms.

  • Infectious disease: A disease caused by a pathogen

    • Emergent infectious disease: An infectious disease that has not been previously described or has not been common for at least the prior 20 years.

  • Acute disease: A disease that rapidly impairs the functioning of a person’s body.

  • Chronic disease: A disease that slowly impairs the functioning of a person’s body.

  • Epidemic: A situation in which a pathogen causes a rapid increase in disease.

  • Pandemic: An epidemic that occurs over a large geographic region, such as an entire continent.

  • Dysentery: An infection of the intestines that causes diarrhea, which results in dehydration and can cause death.

  • Plague: An infectious disease caused by a bacterium (Yersinia pestis) that is carried by fleas.

  • Malaria: An infectious disease caused by one of several species of protists in the genus Plasmodium.

  • Tuberculosis: A highly contagious disease caused by the bacterium Mycobacterium tuberculosis that primarily infects the lungs.

  • Acquired Immune Deficiency Syndrome (AIDS): An infectious disease caused by the human immunodeficiency virus (HIV).

    • Human Immunodeficiency Virus (HIV): A type of virus that causes Acquired Immunodeficiency Syndrome (AIDS).

  • Ebola hemorrhagic fever: An infectious disease with high death rates, caused by several species of Ebola viruses.

  • Mad cow disease: A disease in which prions mutate into deadly pathogens and slowly damage a cow’s nervous system.

    • Prion: A small, beneficial protein that occasionally mutates into a pathogen.

  • Swine flu: A type of flu caused by the H1N1 virus.

  • Bird flu: A type of flu caused by the H5N1 virus.

  • Severe acute respiratory syndrome (SARS): A type of flu caused by a coronavirus.

    • SARS-CoV-2: A coronavirus that causes the disease known as Covid-19.

  • MERS-CoV: A coronavirus that causes the disease known as Middle Eastern Respiratory Syndrome.

  • West Nile virus: A virus that lives in hundreds of species of birds and is transmitted among birds by mosquitoes.

  • Lyme disease: A disease caused by a bacterium (Borrelia burgdorferi) that is transmitted by ticks.

  • Zika virus disease: A disease caused by a pathogen that causes fetuses to be born with unusually small heads and damaged brains.

• Clean Water Act: Legislation that supports the “protection and propagation of fish, shellfish, and wildlife and recreation in and on the water” by maintaining and, when necessary, restoring the chemical, physical, and biological properties of surface waters.

• Safe Drinking Water Act: Legislation that sets the national standards for safe drinking water.

• Maximum contaminant level (MCL): The standard for safe drinking water established by the EPA under the Safe Drinking Water Act.

Unit 9: Global Change

• Chlorofluorocarbons (CFCs): Chemical that can be used for cooling refrigerators and air conditioners.

  • Montreal Protocol: A commitment by 24 nations to reduce CFC production by 50 percent by the year 2000.

• Global change: Change that occurs in the chemical, biological, and physical properties of the planet.

• Global climate change: A type of global change that is focused on changes in the average weather that occurs in an area over a period of years or decades.

• Greenhouse effect: Absorption of infrared radiation by atmospheric gasses and reradiation of the energy back toward Earth.

• Greenhouse warming potential (GWP): An estimate of how much a molecule of any compound can contribute to global warming over a period of 100 years relative to one molecule of CO2

• Ocean acidification: A process in which an increase in ocean CO2 causes more CO2 to be converted to carbonic acid, which lowers the pH of the water.

• Kyoto Protocol: An international agreement that sets a goal for global emissions of greenhouse gasses from all industrialized countries to be reduced by 5.2 percent below their 1990 levels by 2012.

• Paris Climate Agreement: A pledge by 196 countries to keep global warming less than 2°C above pre-industrial levels. Also known as the Paris Climate Accord.

• Endangered species: Species that are likely to go extinct in the near future.

• Lacey Act: A U.S. act that prohibits interstate shipping of all illegally harvested plants and animals.

• Marine Mammal Protection Act: A 1972 U.S. law that prohibits the killing of all marine mammals in the United States and prohibits the import or export of any marine mammal body parts.

• Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES): A 1973 treaty formed to control the international trade of threatened plants and animals.