AP Environmental Science Exam Notes

Ecological Relationships & Population Dynamics

  • Temporal Partitioning:
    • Definition: Resources are used at different times, reducing competition.
  • Spatial Partitioning:
    • Definition: Resources are used in different habitats, reducing competition.

Symbiotic Relationships

  • Parasitism:
    • One organism benefits, the other is harmed.
  • Commensalism:
    • One organism benefits, the other is neither harmed nor helped.
  • Predation:
    • One organism (the predator) kills and consumes another (the prey).

Trophic Levels & Energy Flow

  • NPP (Net Primary Productivity):
    • The rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances.
  • Apex Predator:
    • The top predator in an ecosystem.
  • Trophic Rule:
    • Refers to the 10% rule, where only about 10% of energy is transferred from one trophic level to the next.
  • Biome:
    • A large naturally occurring community of flora and fauna occupying a major habitat, e.g., forest or tundra.
  • Trophic Pyramid:
    • A graphical representation of energy flow in a community.
  • Kcal:
    • Unit of energy, often used to measure energy content in food or biomass.
  • Biomass:
    • The total mass of organisms in a given area or volume.

Ecosystem Services & Biodiversity

  • Provisioning:
    • Definition: Direct products obtained from ecosystems (e.g., food, water, timber).
  • Cultural:
    • Definition: Non-material benefits (e.g., recreation, aesthetic enjoyment).
  • Regulating:
    • Definition: Benefits obtained from regulation of ecosystem processes (e.g., climate regulation, water purification).
  • Supporting:
    • Definition: Services necessary for the production of all other ecosystem services (e.g., nutrient cycling).

Biodiversity & Adaptation

  • Adaptation:
    • A trait that enhances survival and reproduction in a specific environment.
  • Genetic Diversity:
    • The range of different genes within a population.
  • Bottlenecking Event:
    • A sharp reduction in the size of a population due to environmental events or human activities, which can reduce genetic diversity.
  • Selective Pressure:
    • Any factor that affects the survival or reproductive success of individuals with certain traits.

Island Biogeography & Ecological Factors

  • Island Biogeography Rules:
    • Island size affects immigration and extinction rates.
    • Distance from the mainland affects immigration rates.

Ecological Disturbances & Resilience

  • Episodic Natural Disturbance:
    • Natural events that disrupt ecosystem structure and resource availability (e.g., fires, floods).
  • Evolution:
    • Change in the genetic composition of a population over time.
  • Natural Selection:
    • Differential survival and reproduction of individuals due to differences in phenotype.
  • Ecosystem Resilience:
    • The capacity of an ecosystem to recover from disturbance or stress.

Species & Environmental Tolerance

  • Zone of Physiological Stress:
    • The range of environmental conditions where an organism can survive but experiences stress.
  • Zone of Intolerance:
    • The range of environmental conditions where an organism cannot survive.
  • Generalist:
    • A species that can thrive in a wide variety of environmental conditions and make use of a variety of different resources.
  • Specialist:
    • A species that can thrive only in a narrow range of environmental conditions or has a limited diet.

Population Ecology

  • Carrying Capacity:
    • The maximum population size that an environment can sustain.
  • Survivorship Curve:
    • A graph showing the number or proportion of individuals surviving to each age for a given species or group.
  • r-selected Species:
    • Species with high reproductive rates and short lifespans, adapted to unstable environments.
  • K-selected Species:
    • Species with low reproductive rates and long lifespans, adapted to stable environments.
  • Age Structure Diagram:
    • A graphical representation of the distribution of different age groups in a population.
  • TFR (Total Fertility Rate):
    • The average number of children a woman is expected to have in her lifetime.
  • Growth Rate:
    • The rate at which a population increases (or decreases) in size per unit of time.
  • Rule of 70:
    • A way to estimate the number of years it takes for a certain variable to double.
  • % Change Formula:
    • Used to calculate the percentage change in a value over time.

Earth Systems & Geology

  • Doubling Time Formula:
    • DoublingTime=70/GrowthRateDoublingTime = 70/GrowthRate
  • Percent Change Formula:
    • ((NewValue−OldValue)/OldValue)∗100((NewV alue − OldV alue)/OldV alue) ∗ 100

Levels of the Earth

  • Inner Core
  • Outer Core
  • Mantle
  • Asthenosphere
  • Lithosphere

Plate Tectonics

  • Convergent Plate Boundary:
    • Where two plates collide.
  • Transform Fault Plate Boundary:
    • Where two plates slide past each other horizontally.
  • Divergent Plate Boundary:
    • Where two plates move away from each other.

Soil Composition

  • Sand:

    • Largest particles, good for drainage.

  • Clay:

    • Smallest particles, good for water retention.

  • Silt:

    • Intermediate-sized particles.

  • Soil Testing:

    • pH Test: Measures the acidity or alkalinity of the soil.
    • Horizon: A layer of soil that is parallel to the soil surface and has distinct characteristics

Atmospheric & Oceanic Processes

  • Solar Radiation & Heat:

    • Insolation: The amount of solar radiation reaching a given area.
    • Albedo: The reflectivity of a surface.
    • Urban Heat Island: An urban area that is significantly warmer than its surrounding rural areas due to human activities.

  • Ocean Currents:

    • Upwelling Zone: An area where deep, cold water rises to the surface, bringing nutrients
    • Thermohaline Circulation: A global ocean current driven by differences in temperature and salinity.

  • Atmospheric Circulation:

    • Hadley Cell: A global-scale atmospheric circulation pattern where air rises near the equator, flows poleward at high altitudes, sinks in the subtropics, and flows back towards the equator at low altitudes.

Resource Management & Agriculture

  • Tragedy of the Commons:

    • Definition: A situation where individuals acting independently and rationally, deplete a shared resource even when doing so is not in their best interest.

  • Forestry Practices:

    • Clearcutting: Removing all trees from an area.
    • Tree Plantations: Managed forests with uniformly aged trees of a single species.
    • Deforestation: The clearing of forests for other land uses.

  • Agricultural Practices:

    • The Green Revolution: A period of increased agricultural productivity due to new technologies.
    • Genetically Modified Crops: Crops whose DNA has been altered.
    • Monocropping: Growing a single crop in a field.
    • Tilling: Turning over the soil to prepare it for planting.
    • Eutrophication: Excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen.
    • Algae Bloom: Rapid increase in the population of algae in an aquatic system.
    • Soil Salinization: The buildup of salts in the soil surface, often due to irrigation.
    • Aquifer: A body of permeable rock that can contain or transmit groundwater.

Energy Sources & Impacts

  • Fuel Source Pros & Cons:

    • Nuclear:
      • Downside: Nuclear waste, potential for accidents
      • Benefit: High energy output, low greenhouse gas emissions during operation
    • Solar:
      • Downside: Intermittent, requires large land area
      • Benefit: Renewable, low operating costs
    • Hydroelectric:
      • Downside: Disrupts river ecosystems, can displace communities
      • Benefit: Renewable, reliable energy source
    • Natural Gas:
      • Downside: Greenhouse gas emissions (methane), fracking impacts
      • Benefit: Lower emissions than coal, relatively abundant
    • Wind Power:
      • Downside: Visual impact, noise pollution, can harm birds and bats
      • Benefit: Renewable, low operating costs

  • Cogeneration:

    • The use of a heat engine or power station to simultaneously generate both electricity and useful heat.

  • Energy Calculation Formulas:

    • MPG (Miles Per Gallon) Calculations:
      • Milesdriven/GallonsoffuelusedMiles driven / Gallons of fuel used
    • Energy Usage Per Year:
      • Power(kW)∗Hoursofuseperday∗DaysofuseperyearPower(kW) ∗ Hours of use per day ∗ Days of use per year

Air Quality & Pollution

  • Criteria Air Pollutants:

    • 6 criteria air pollutants:
      • Ozone
      • Particulate Matter
      • Carbon Monoxide
      • Lead
      • Sulfur Dioxide
      • Nitrogen Dioxide

  • Types of Air Pollutants:

    • Primary Air Pollutant: Emitted directly from a source.
    • Secondary Air Pollutant: Formed in the atmosphere as a result of chemical reactions.
    • Smog: Air pollution that reduces visibility.
    • Thermal Inversion: A condition where a layer of warm air traps cooler air near the surface.
    • Asbestos: A fibrous mineral that can cause lung cancer and other respiratory diseases.
    • Carbon Monoxide: A colorless, odorless gas that can cause asphyxiation.
    • Lead: A toxic metal that can damage the nervous system and other organs.
    • Noise Pollution: Harmful or annoying levels of noise.

Experimental Design & Toxicology

  • Experimental Variables:

    • Independent Variable: The variable that is manipulated by the researcher.
    • Dependent Variable: The variable that is measured by the researcher.
    • Control Group: A group that does not receive the experimental treatment.
    • Hypothesis: A testable statement about the relationship between two or more variables.

  • Stress & Endocrine Disruptors:

    • Physiological Stress: The effect of a physical or psychological demand on an organism.
    • Tolerance Level: The range of environmental conditions that an organism can tolerate.
    • Endocrine Disruptors: Chemicals that interfere with the endocrine system.

Pollution Types & Impacts

  • Sewage Treatment Plants:
    • Facilities that treat wastewater to remove pollutants.
  • Toxic Metals: *Mercury: A toxic metal that can bioaccumulate in food chains. *Lead: A toxic metal that can damage the nervous system and other organs. *Arsenic: A toxic metalloid that can contaminate water and soil.
    • POPs (Persistent Organic Pollutants): Toxic chemicals that persist in the environment.
  • Nutrient Pollution: Excessive input of nutrients into aquatic ecosystems.
  • Bio Magnification: The increasing concentration of a substance in the tissues of organisms at successively higher levels in a food chain.
  • Bio Accumulation: The accumulation of substances, such as pesticides, or other organic chemicals in an organism.
  • Landfills: Sites for the disposal of waste materials.

Waste Management & Environmental Health Vocabulary

  • Non-point source: Pollution that comes from many diffuse sources (e.g., agricultural runoff).
  • Anthropogenic activities: Human activities that impact the environment (e.g., burning fossil fuels).
  • P.O.P.s: Persistent Organic Pollutants - Chemicals that effect a person's hormone levels.
  • Effluent: Liquid waste or sewage discharged into a river or the sea.
  • Inorganic solid waste: Non-decomposable waste materials; Waste that collects at the bottom of tanks during 1st and 2nd steps of sewage treatment
  • Compost: Decayed organic material used as a plant fertilizer.
  • Thermal shock: Sudden temperature change in an environment.
  • Biomagnification: The increasing concentration of a substance in the tissues of organisms at successively higher levels in a food chain; Absorption and concentration of compounds (especially fat-soluble ones like POPs) in the cells & fat tissues of organisms
  • Toxicity: The degree to which a substance is poisonous or can cause harm (e.g., cellphones, laptops, computers).
  • Threshold: The level or point at which something starts to happen or have an effect.
  • LD50: The amount of a substance required to kill 50% of a test population.
  • Chlorofluorocarbons: Organic compound that contains only carbon, chlorine, and fluorine, produced as a volatile derivative of methane, ethane, and propane.
  • Natural Ozone Depletion: When natural reactions destroy ozone more quickly than it is created, ozone levels may be significantly lower.
  • Greenhouse Effect: The trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared.
  • Green House Gasses: A gas that contributes to the greenhouse effect by absorbing infrared radiation
  • Thermal Expansion: The tendency of matter to change in volume in response to changes in temperature.
  • Milankovich cycles: Periodic changes in Earth's orbit and tilt that affect climate.
  • Ocean Acidi cation: The ongoing decrease in the pH of the Earth's oceans, caused by the uptake of carbon dioxide (CO2) from the atmosphere.
  • Invasive Species: A non-native species that causes harm to the environment, economy, or human health.
  • H I P P C O: Habitat Destruction, Invasive Species, Population Growth, Pollution, Climate Change, Overexploitation
  • Biodiversity loss: The decline in the number and variety of species in an ecosystem.