Biomes: Tundra and Desert

Biome Definition

• A biome is a large geographic area characterized by specific climate patterns along with distinct flora and fauna.

Tundra Biome Characteristics

• Climate: Very low temperatures, low rainfall, strong winds, and short growing seasons (average -12 to -6°C, less than 25 mm rainfall).
• Flora: Low-growing, dense, and small plants, some with fur-like adaptations (e.g., cottongrass and arctic poppy).
• Fauna: Animals with thick, warm fur and shorter extremities to reduce heat loss (e.g., polar bear and arctic fox).
• Adaptations: Many animals (bears and squirrels) hibernate, while others (birds, hares, foxes) adapt to remain active year-round; plants are adapted to endure long, cold winters with stunted growth.

Desert Biome Characteristics

• Climate: Very hot days (average 35–40°C) and cold nights (below 0°C), with very low rainfall (under 250 mm).
• Flora: Sparse, low-lying plants with thorns, thick skin, and shallow roots to store water (e.g., cactus).
• Fauna: Nocturnal or burrowing animals with adaptations like large ears to release heat (e.g., fennec fox) and humps to conserve water (e.g., camel).
• Adaptations: Animals rest during the day, and plants grow slowly, surviving extreme heat and drought.

Spatial Distribution of the Tundra Biome

• Location: Arctic regions in North America, Europe, and Asia.
• Latitude: Polar zone, at high latitudes (60-75 degrees), receiving minimal sunlight.
• Climate: Long, harsh winters (-12 to -6°C) with minimal rain (less than 25 ml).
• Topography: Flat or gently rolling terrain.
• Altitude: High altitudes.
• Proximity to Ocean: Located near the sea.

Human Alteration of Biomes

• Land terracing: Constructing steps on slopes to decrease erosion and improve water retention for farming.
• Irrigation: Manually adding water to the soil from natural water sources.

Irrigation: Description and Impact

• Description: Water is manually added to soil from natural water bodies to support crop growth in dry areas with limited rainfall.
• Impact:
  • Soil salinity: Salt accumulation in the soil.
  • Reduced soil fertility: Salt buildup hinders plant absorption of nutrients and water.
  • Ecological disruption: Excessive water extraction lowers water levels, disrupting natural water flow.

Strategies to Minimize Irrigation Impacts

• Crop rotation:
  • Growing different crops on the same field across seasons.
  • This varies nutrient demands, enhances soil structure, and improves drainage thus reducing salinity's impact as the water is pushed deeper than the root levels.
• No-tillage farming:
  • Growing crops without disturbing the soil.
  • Helps retain moisture, preserves organic matter and pores, and improves overall soil health and fertility.

Agricultural Yields Definition

• Agricultural yield refers to the amount of a specific crop produced per unit of land area.

Factors Influencing Agricultural Yields

• Economic: Global supply and demand, along with competition.
• Environmental: Abiotic and biotic factors, essential for specific growth needs.
• Technological: Influence performance and efficiency.

Temperature and Water Availability Influence on Agricultural Yields

• Water scarcity:
  • Limits crop growth and irrigation (crops typically need 500-800mm of water).
  • Decreases livestock productivity.
• Temperature:
  • Affects crop growth, each plant has an optimal temperature.
  • Temperatures that are too hot or too cold damages all plantlife, also affects the health of livestock.

Technology to Increase Agricultural Yields

• Drones and Precision Farming:
  • Real-time data and photos provide precise monitoring for early problem detection and smooth crop growth.
  • Soil analysis, pest, and plant data for precise planting.
• Vertical Farming:
  • Stacking crops vertically increases output within the same footprint, which can lead to more profit.
  • Controlled weather conditions optimize crop performance.
• GMO (Genetically Modified Organisms):
  • Genes are modified to improve survival, increase nutritional value, and resist pests.
  • Improves profit margins due to greater and upgraded crop yields.
  • One example is corn modified with bacterial insecticides emitting insect toxins to eliminate pests.

Biosphere Scale

• Individual: A single organism.
• Population: A group of organisms of the same species.
• Community: A group of organisms of different species.
• Ecosystem: Connected interactions between abiotic and biotic features.
• Biomes: Large geographical areas.
• Biosphere: All living things.

Spatial Distribution of Biomes Around the World

• Tropic zone (0 to 23.5°N/S): Tropical rainforest.
• Subtropical zone (23.5°N/S to 35°N/S): Grassland, desert.
• Temperate zone (23.5°N/S to 66.5°N/S): Taiga, temperate forest.
• Polar (66.5°N/S to 90°N/S): Tundra, polar desert.

Factors Influencing Biome Distribution

• Latitude: How much sunlight can grow in a said biome.
• Climate: Different climates control what can grow within the region.
• Topography: Creates microclimates affecting which biomes can thrive.
• Altitude: Locations that have a bigger affect of climate and weather, and colder temperatures.
• Distance from the ocean: Locations near the ocean have more moisture, resulting in more vegetation due to more stable weather. Locations more inland are drier and have more distinct weather conditions.

Impact of Land Degradation on Food Production

• Urban expansion: Converts farmlands into urban areas, reducing space for food production.
• Biofuel production: Reduces food crop quantities for fuel production, creating shortages and higher prices.