AP Environmental Science Unit 1 Review

Introduction

• Instructor: Mr. Smees
• Target Exams: APES Unit Exams, Final, AP Exam in May
• Resource: Use the Unit 1 Ultimate Review Packet (includes study guides, practice questions, exams)
• Common Mistake: Students struggle with Free Response Questions (FRQs). Practice is essential.

Unit 1: Ecosystems

• This unit is a review of previously learned content.
• For in-depth videos on specific topics, visit Mr. Smees' YouTube channel.

Topic 1.1: Introduction to Ecosystems

• Ecosystem: Interaction of living and non-living things in a specific region.
• Environment: The entire natural world.
• Habitat: Specific environmental conditions required by a species.
• Species Interactions:
  • Competition: Fighting over resources.
  • Symbiosis: Close living relationships, not always mutually beneficial.
  • Mutualism: Both species benefit (e.g., bees and plants).
• Misconception: Symbiosis ≠ Mutualism.

Topics 1.2 & 1.3: Terrestrial and Aquatic Biomes

• Biomes: Regions with consistent yearly temperature and precipitation.
• Examples: Tropical rainforests (high temp and precip) vs. tundra (low temp and precip).
• Biome Shift: Biomes can shift with changing climate patterns.
• Aquatic Biomes Factors: Salinity, flow, and depth.
• Example Biome: Estuaries (unique salinity levels, nutrient-rich).

Biogeochemical Cycles

Topic 1.4: Law of Conservation of Matter

• Matter is never created or destroyed, only changes forms.
• Focus on Carbon, Nitrogen, Phosphorus, and Water cycles.

Topic 1.5: Carbon Cycle

• Carbon Sources: Return carbon to atmosphere.
• Carbon Sinks: Remove carbon from atmosphere.
• Atmosphere as a Reservoir: Determines global climate.
• Photosynthesis & Respiration: Photosynthesis removes carbon, respiration adds carbon.
• Human Impact: Combustion of fossil fuels adds ancient carbon to atmosphere.

Topic 1.6: Nitrogen Cycle

• Major Reservoir: Atmosphere (unusable in gas form for plants/animals).
• Nitrogen Fixation: Converts nitrogen into usable forms (ammonia, nitrate).
• Fixation By: Bacteria, lightning, fossil fuel combustion.
• Importance: Plants need fixed nitrogen for assimilation.

Topic 1.7: Phosphorus Cycle

• No Gas Phase: Phosphorus cycles slowly.
• Major Reservoirs: Rocks and sediments.
• Weathering: Releases phosphates from rocks.
• Limiting Nutrient: Often limits growth due to slow cycling.

Topic 1.8: Water Cycle

• Driven by Sun: Evaporation, condensation, and precipitation.
• Key Steps:
  • Infiltration: Water seeping into soil.
  • Transpiration: Water from plants entering the atmosphere.
• Major Reservoir: Oceans (not directly usable by humans).

Energy Flow in Ecosystems

Topic 1.9: Primary Productivity

• Definition: Rate of photosynthesis in an area.
• Gross vs. Net Productivity:
  • Gross Primary Productivity (GPP): Total energy produced.
  • Net Primary Productivity (NPP): Energy stored after respiration.
• Formula: NPP = GPP - Respiration Loss

Topic 1.10: Energy Movement in Trophic Levels

• Trophic Pyramid: Shows energy flow in ecosystems.
• 10% Rule: Only 10% of energy transfers to the next level.
• Implication: Large predators require vast spaces.

Topic 1.11: Food Webs and Chains

• Arrows Represent: Movement of energy and matter.
• Trophic Cascades: Removal of species affects entire ecosystem.
• Predator Impact: Can lead to overgrazing or population changes.

Conclusion

• Make sure to use the Ultimate Review Packet for practice and understanding.
• Encouragement: Continue thinking like a mountain and writing like a scholar.

• Resources Available:
  • Unit 1 Ultimate Review Packet
  • Mr. Smees' YouTube channel for detailed video reviews.