AP Environmental Science Review: Unit 1 - Ecosystems

Introduction

• Instructor: Mr. Smees
• Purpose: Help prepare for AP Environmental Science (APES) exams.
• Materials:
  • Ultimate review packet available in the video description.
  • Contains study guides, practice questions, and full-length practice exams.
• Key Focus: Practice Free-Response Questions (FRQs).

Ecosystems Overview

• Ecosystem Definition: Interaction of living and non-living things in a specific region.
• Environment Definition: Refers to the entire natural world.
• Habitat Definition: Environmental conditions needed by a species to survive.

Species Interactions

• Symbiosis: Organisms living in close proximity, not necessarily mutualistic.
• Mutualism: Both species benefit (e.g., bees and plants, coral and algae).

Biomes

• Definition: Regions sharing consistent temperature and precipitation patterns.
• Examples:
  • Tropical Rainforest: High temperature and precipitation.
  • Tundra: Low temperature and precipitation.
• Key Points: Determined by temperature and precipitation.

Terrestrial and Aquatic Biomes

• Aquatic Biomes Influencing Factors: Salinity, flow, and depth.
• Estuaries: Unique salinity levels (brackish), important for nutrients and biodiversity.

Matter Cycles

• Law of Conservation of Matter: Matter is neither created nor destroyed.

Carbon Cycle

• Sources: Return carbon to the atmosphere.
• Sinks: Take carbon out of the atmosphere.
• Processes: Photosynthesis (removes carbon), respiration (returns carbon), combustion (returns ancient carbon).

Nitrogen Cycle

• Differences from Carbon Cycle:
  • Nitrogen cycles faster.
  • Atmospheric nitrogen is biologically unavailable.
• Nitrogen Fixation: Converts atmospheric nitrogen to usable forms, primarily by bacteria.

Phosphorus Cycle

• No Gas Phase: Cycles more slowly.
• Reservoirs: Rocks and sediments.
• Weathering & Erosion: Release phosphorus into the ecosystem.

Water Cycle

• Driven by Sun's Energy: Evaporation and precipitation processes.
• Reservoirs: Oceans (main, unusable for drinking/agriculture), freshwater sources.

Energy Flow through Ecosystems

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 losses.
• Equation: NPP = GPP - Respiration Loss

Trophic Pyramids

• Structure: Representation of energy flow.
• Energy Transfer: Only 10% of energy moves to the next level (10% rule).

Food Webs and Chains

• Energy and Matter Movement: Arrows show direction.
• Trophic Cascades: Removal of one species affects the entire ecosystem (e.g., predator removal).

Conclusion

• Study Materials: Review packets and additional resources are essential.
• Overall Goal: Develop a strong understanding of unit concepts to prepare for exams.
• Additional Help: Use video lessons for detailed topic reviews.