Video Notes for Topic 1.2: Terrestrial Biomes

Objective

• Describe global distribution and environmental conditions of land-based biomes.
• Understand how plants and animals are adapted to their unique climates.
• Discuss major biomes relevant for AP Environmental Science (APES).
• Explore how climate change affects biome distribution.
• Practice explaining an environmental concept or process.

Definition of Biomes

• Biomes: Areas defined by average yearly temperature and precipitation (climate).

Key Biomes

• Rainforest: High rainfall, warm temperatures.
• Desert: Low precipitation, may have high temperatures.

Adaptations of Organisms

• Organisms in biomes are uniquely adapted to survive climate conditions.
  • Desert Adaptations:
    • Camels: Hump stores fat for energy during food scarcity.
    • Cacti: Thick, waxy cuticle prevents water loss.
  • Grasslands Adaptations:
    • Shrubs/Wildflowers: Deep roots store energy to regrow after wildfires.

Characteristics of Biomes

• Defining Characteristics: Temperature and precipitation.
  • Tropical seasonal forest/savanna:
    • Precipitation: 60-280 cm/year.
    • Temperature: 18-29 °C.

Global Distribution Patterns

• Biomes have predictable patterns related to latitude:
  • Tundra & Boreal Forest:
    • Low precipitation, colder temperatures, found around 60° latitude.
  • Temperate Biomes:
    • Moderate rainfall and temperature, found between 30-60° latitude.
  • Tropical Biomes:
    • Warm temperatures, high rainfall, concentrated around the equator.

Nutrient Availability

• Nutrient availability in soil determines what plants can survive:
  • Tundra: Permanently frozen soil leads to low nutrient recycling and low plant diversity.
  • Tropical Rainforest: High plant competition leads to low nutrient availability.
  • Boreal Forest: Cold temperatures slow decomposition, resulting in nutrient-poor soil.
  • Temperate Forest: High nutrient levels due to leaf litter decomposition and moderate temperatures.

Impact of Climate Change on Biomes

• Climate is not stable and is changing due to human activities.
• Biomes may shift in location due to warming:
  • Boreal Forests: Moving north as soils thaw.
  • Aspen Range Shift: Predicted range shift from 1971-2100 due to temperature increases.
  • Example of arctic land in 1962 and 2004 shows forest creeping northward due to global warming.

Practice Activity

• Identify one characteristic of a biome and explain how it determines the community of organisms found in that biome.

Conclusion

• Encourage students to like the video, subscribe for updates, and review other available notes.
• Reminder: "Think like a mountain, write like a scholar."