AP Environmental Science Unit 1 Review: Ecosystems

Presented by Mr. Smees, focusing on preparation for the AP Environmental Science Unit Exams, Final Exam, and AP Exam.

Introduction

• Free Study Resources:
  • Access the Unit 1 Ultimate Review Packet for study guides, practice questions, and full-length practice exams with answer keys.
• Key Exam Advice:
  • Practice FRQs (Free Response Questions) extensively.

Ecosystems Overview

• Definitions:
  • 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: Organisms fighting over resources.
  • Symbiosis vs Mutualism:
    • Symbiosis: Close living relationship, which can include parasitic relationships.
    • Mutualism: Both species benefit (e.g., bees and plants, coral reefs).

Terrestrial and Aquatic Biomes

• Definition of Biomes: Region with consistent yearly temperature and precipitation.
• Examples:
  • Tropical Rainforest: High temperature and precipitation.
  • Tundra: Low temperature and precipitation.
• Biome Characteristics: Determined by temperature and precipitation patterns.
• Biome Shifts: Changes in temperature and precipitation can shift biome locations.
• Aquatic Biomes Factors: Salinity, flow, and depth.
• Estuaries: Unique due to brackish water and high productivity from nutrient-rich sediments.

Matter Cycles

Law of Conservation of Matter

• Matter is never created or destroyed, only changes form.

Carbon Cycle

• Carbon Sources and Sinks:
  • Sources: Return carbon to the atmosphere.
  • Sinks: Take carbon out of the atmosphere.
• Key Processes:
  • Photosynthesis: Removes carbon from the atmosphere.
  • Respiration: Returns carbon to the atmosphere.
  • Extraction and Combustion: Human activity returning long-stored carbon (e.g., fossil fuels).

Nitrogen Cycle

• Differences from Carbon Cycle:
  • Faster cycle with biologically unavailable atmospheric form.
• Nitrogen Fixation: Converts atmospheric nitrogen into usable forms (e.g., ammonia, nitrate) by bacteria.

Phosphorus Cycle

• No Gas Phase: Slow cycling due to reliance on weathering of rocks.
• Phosphorus as a Limiting Nutrient: Often limits plant growth due to its slow release from rocks.

Water Cycle

• Sun-Driven Cycle: Evaporation, condensation, precipitation.
• Key Processes:
  • Infiltration: Water seeping into soil.
  • Transpiration: Water vapor released by plants.

Energy Flow in Ecosystems

Primary Productivity

• Definition: Rate of photosynthesis in a given area.
• Types:
  • Gross Primary Productivity (GPP): Total energy produced.
  • Net Primary Productivity (NPP): Energy stored after respiration losses.

Trophic Pyramids

• Structure:
  • Base: Producers (plants).
  • Higher Levels: Primary, secondary, tertiary consumers.
• Energy Transfer:
  • 10% Rule: Only 10% of energy transfers to the next level; 90% is lost.

Food Webs and Chains

• Energy Flow Representation: Arrows show movement of energy and matter.
• Trophic Cascades: Effects predators have on ecosystems by controlling herbivore populations.

Conclusion

• Review and Study Resources:
  • Utilize the Unit 1 Ultimate Review Packet and additional online resources for in-depth topic coverage.
• Mutualistic Relationship with Mr. Smees: Support and resources exchange to aid exam preparation.

Remember to think like a mountain and write like a scholar!