APES CHAT CARDS

Here's a high-quality, comprehensive set of AP Environmental Science (APES) flashcards, organized by unit. These are designed to help you prepare effectively for the AP exam. Each card includes a key concept or term, definition, and real-world connection or example when applicable.


Unit 1: The Living World – Ecosystems

1. Ecosystem
Definition: A biological community of interacting organisms and their physical environment.
Example: Coral reef or a rainforest.

2. Biotic vs. Abiotic
Definition: Biotic = living components (plants, animals); Abiotic = non-living (temperature, pH).
Tip: Think: B for Bear (biotic), A for Air (abiotic).

3. Trophic Levels
Definition: Levels of a food chain (producers → primary consumers → secondary...).
Example: Grass → rabbit → fox → eagle.

4. Net Primary Productivity (NPP)
Definition: Energy captured by producers minus energy lost via respiration.
Importance: Determines how much energy is available to higher trophic levels.

5. Nitrogen Cycle
Steps: Fixation → Nitrification → Assimilation → Ammonification → Denitrification.
Human Impact: Fertilizer use → eutrophication.


Unit 2: The Living World – Biodiversity

6. Species Richness vs. Evenness
Definition: Richness = number of species; Evenness = distribution.
High biodiversity = high resilience.

7. Ecosystem Services
Types: Provisioning, Regulating, Cultural, Supporting.
Example: Bees pollinating crops (regulating service).

8. Island Biogeography Theory
Concept: Biodiversity depends on island size and distance from mainland.
Application: Explains species loss in fragmented habitats.

9. Natural Disruptions
Definition: Events like wildfires, floods, hurricanes affecting ecosystems.
AP Tip: Distinguish between natural and anthropogenic disruptions.


Unit 3: Populations

10. Carrying Capacity (K)
Definition: Maximum population size an environment can sustain.
Sign of Reaching K: Increased competition, dieback.

11. R-Selected vs. K-Selected Species
R-Selected: Many offspring, little care (e.g., insects).
K-Selected: Few offspring, high parental care (e.g., elephants).

12. Survivorship Curves
Type I: High survival until old age (humans).
Type II: Constant death rate (squirrels).
Type III: High early mortality (frogs).

13. Total Fertility Rate (TFR)
Definition: Average # of children a woman will have.
Replacement Level: ~2.1 in developed countries.


Unit 4: Earth Systems and Resources

14. Plate Tectonics
Types: Divergent, Convergent, Transform boundaries.
Hazards: Earthquakes, volcanoes.

15. Soil Horizons (O, A, B, C, R)
Mnemonic: Only Aardvarks Bathe Carefully Regularly.
O = Organic layer, A = Topsoil, B = Subsoil...

16. Watershed
Definition: Area of land where water drains into a common waterway.
AP Tip: Be able to describe how land use affects watersheds.

17. El Niño
Effect: Weak trade winds, warmer Pacific waters, disrupted weather.
Impacts: Droughts, floods, decreased upwelling.


Unit 5: Land and Water Use

18. Tragedy of the Commons
Definition: Individuals overuse shared resources.
Example: Overfishing in oceans.

19. Clearcutting
Impact: Erosion, loss of biodiversity, increased CO₂.
Alternatives: Selective cutting, sustainable forestry.

20. Green Revolution
Definition: Increase in agricultural yield through chemicals and GMOs.
Consequences: Soil degradation, pesticide resistance.

21. CAFOs vs. Free-range Grazing
CAFOs: Efficient but polluting.
Free-range: Better for environment, more space.

22. Irrigation Types
Most efficient: Drip irrigation.
Least efficient: Flood irrigation.


Unit 6: Energy Resources and Consumption

23. Nonrenewable vs. Renewable Energy
Nonrenewable: Coal, oil, natural gas.
Renewable: Solar, wind, hydro, geothermal, biomass.

24. Energy Return on Investment (EROI)
Definition: Ratio of energy output to energy input.
Higher EROI = more efficient source.

25. Coal Power Plant
Steps: Burn coal → heat water → steam spins turbine → generates electricity.
Pollution: CO₂, SO₂, particulates.

26. Passive vs. Active Solar
Passive: Uses building design.
Active: Uses solar panels and pumps.


Unit 7: Atmospheric Pollution

27. Primary vs. Secondary Pollutants
Primary: Emitted directly (CO, SO₂).
Secondary: Form in atmosphere (O₃, smog).

28. Photochemical Smog
Formation: VOCs + NOx + sunlight = Ozone.
Worse in: Warm, sunny cities with lots of traffic.

29. Thermal Inversion
Definition: Warm air traps pollutants near surface.
Health Risk: Increased respiratory problems.

30. Acid Rain
Cause: SO₂ + NOx → sulfuric/nitric acid in rain.
Effect: Damages forests, aquatic systems.


Unit 8: Aquatic and Terrestrial Pollution

31. Eutrophication
Definition: Nutrient runoff → algal blooms → oxygen depletion.
Sources: Fertilizers, sewage.

32. Dead Zones
Example: Gulf of Mexico.
Cause: Excess nutrients and eutrophication.

33. Bioaccumulation vs. Biomagnification
Bioaccumulation: Toxin in one organism.
Biomagnification: Toxin increases up food chain.

34. Solid Waste Types
MSW: Municipal solid waste (trash).
Hazardous waste: Toxic, corrosive, flammable.


Unit 9: Global Change

35. Greenhouse Effect
Definition: GHGs trap infrared heat in atmosphere.
Key GHGs: CO₂, CH₄, N₂O, H₂O vapor.

36. Global Warming Potential (GWP)
CO₂ = 1; Methane = 25x; N₂O = 300x.

37. Ocean Acidification
Cause: CO₂ + H₂O = Carbonic acid.
Effect: Weakens shells of marine organisms.

38. Endangered Species Act
Purpose: Protect species from extinction.
Enforcement: USFWS and NOAA.

39. CITES Treaty
Goal: Prevent illegal wildlife trade.
Success: Banned ivory trade, protected whales.

Great! Here are 4–7 additional flashcards for each AP Environmental Science (APES) unit, continuing from the strong foundation we already created. These additions will deepen your understanding and help with free-response and multiple-choice sections alike.


Unit 1: The Living World – Ecosystems (Additions)

40. 10% Rule
Only about 10% of energy is passed from one trophic level to the next.
Example: 1000 kcal → 100 kcal → 10 kcal...

41. Chemosynthesis
Process by which organisms produce energy using chemicals (not sunlight).
Example: Deep-sea vent bacteria.

42. Gross Primary Productivity (GPP)
Total amount of solar energy captured by producers.
NPP = GPP - Respiration.

43. Hydrologic Cycle
Processes: Evaporation → Condensation → Precipitation → Infiltration/Runoff.
Human Impact: Impervious surfaces increase runoff.

44. Phosphorus Cycle
Does NOT involve atmosphere.
Main source = weathered rock; impact = eutrophication.

45. Carbon Sink
Stores carbon for long periods.
Example: Forests, oceans, fossil fuels.


Unit 2: The Living World – Biodiversity (Additions)

46. Genetic Diversity
Increases a population’s chance of survival under environmental stress.
Low diversity = vulnerable to disease.

47. Ecological Tolerance
Range of abiotic conditions an organism can handle.
Example: Salmon require cold, oxygen-rich water.

48. Indicator Species
Sensitive to environmental change.
Example: Amphibians signal ecosystem health.*

49. Keystone Species
Has a disproportionately large effect on its ecosystem.
Example: Sea otters control sea urchin populations.*

50. Specialist vs. Generalist Species
Specialist: Narrow niche (e.g., panda).
Generalist: Broad niche (e.g., raccoon).

51. Ecological Succession (Primary vs. Secondary)
Primary: No soil (lava, glacial retreat).
Secondary: Soil remains (fire, flood).


Unit 3: Populations (Additions)

52. Rule of 70
Formula for doubling time: 70 ÷ growth rate (%).
Example: 2% growth → 35 years to double.*

53. Age Structure Diagrams
Broad base = rapid growth, narrow base = declining population.
Useful for predicting future population trends.

54. Population Momentum
Continued population growth despite falling fertility rates.
Due to large proportion of reproductive-aged people.

55. Density-Dependent vs. Independent Factors
Dependent: Competition, disease.
Independent: Natural disasters.

56. Demographic Transition Model
Stages: Pre-industrial → Transitional → Industrial → Post-industrial.
Shows change in birth/death rates with development.


Unit 4: Earth Systems and Resources (Additions)

57. Soil Texture Triangle
Determines soil type based on % of sand, silt, clay.
Loam = best for agriculture.

58. Earth's Atmospheric Layers
From bottom: Troposphere → Stratosphere → Mesosphere → Thermosphere.
Ozone layer is in the stratosphere.

59. Coriolis Effect
Deflects moving air/water due to Earth’s rotation.
Right in Northern Hemisphere, left in Southern.

60. Hadley Cell
Global circulation pattern from equator to 30° latitude.
Rising moist air → deserts at 30°.

61. Insolation
Incoming solar radiation. More at equator, less at poles.
Drives weather and climate.


Unit 5: Land and Water Use (Additions)

62. Urban Sprawl
Expansion of urban areas into natural land.
Impacts: Habitat loss, increased emissions, runoff.

63. Integrated Pest Management (IPM)
Combines biological, chemical, and physical pest control methods.
Goal: Minimize pesticide use.

64. Slash-and-Burn Agriculture
Destroys forest for temporary farming.
Causes CO₂ emissions, nutrient loss.

65. Aquaculture
Farming of aquatic organisms.
Pros: Efficient; Cons:* Waste, disease spread.

66. Drip Irrigation
Delivers water directly to roots.
Most efficient irrigation method.

67. Overburden
Top layers removed in mining.
Leads to habitat destruction.


Unit 6: Energy Resources and Consumption (Additions)

68. Peat
Precursor to coal; partially decayed organic matter.
Low energy density, used in some countries.

69. Hydraulic Fracturing (Fracking)
Extracts natural gas by fracturing rock layers.
Issues: Water use, groundwater contamination.*

70. Cogeneration
Uses waste heat from electricity generation.
Increases efficiency.

71. Wind Energy
Clean, renewable; best in open, windy areas.
Downside: Intermittent, affects birds/bats.*

72. Geothermal Energy
Uses Earth’s internal heat.
Best near tectonic activity.

73. Passive Solar Design
Design homes to absorb and store solar heat.
Example: South-facing windows, thermal mass.*


Unit 7: Atmospheric Pollution (Additions)

74. Particulate Matter (PM2.5, PM10)
Tiny particles harmful when inhaled.
Source: Combustion, dust.

75. Lead (Pb)
Toxic metal once common in gasoline and paint.
Neurotoxin, especially harmful to children.

76. Noise Pollution
Can disrupt animal communication and stress humans.
Example: Airport, traffic noise.*

77. Vapor Recovery Nozzles
Capture gasoline vapors at fuel pumps.
Reduce VOC emissions.

78. Scrubbers and Electrostatic Precipitators
Scrubbers: Remove SO₂.
ESPs: Remove particulates from emissions.


Unit 8: Aquatic and Terrestrial Pollution (Additions)

79. Thermal Pollution
Warmer water lowers oxygen levels.
Source: Power plant discharge.

80. Cultural Eutrophication
Human-caused nutrient input into water bodies.
Can create hypoxic (low oxygen) zones.

81. Septic Systems
Rural wastewater treatment.
Includes tank and drain field.

82. LD₅₀ (Lethal Dose 50%)
Dose that kills 50% of test organisms.
Used to assess toxicity.

83. POPs (Persistent Organic Pollutants)
Long-lasting, toxic chemicals like DDT, PCBs.
Fat-soluble, bioaccumulate.

84. Clean Water Act
Regulates pollutant discharges into U.S. waters.
Protects surface water quality.


Unit 9: Global Change (Additions)

85. Climate vs. Weather
Climate = long-term average; Weather = short-term conditions.
Example: Heat wave (weather), global warming (climate).*

86. Melting Permafrost
Releases methane, a powerful greenhouse gas.
Positive feedback loop.

87. Invasive Species
Non-native species that outcompete natives.
Example: Kudzu, zebra mussels.*

88. Coral Bleaching
Caused by warm water, pollution.
Zooxanthellae expelled → coral turns white.

89. Carbon Footprint
Total greenhouse gas emissions caused by an individual, organization, etc.
Lower by reducing meat, travel, and energy use.

90. Montreal Protocol
International treaty banning ozone-depleting substances like CFCs.
Successful example of global cooperation.


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