Terrestrial biomes are Earth's major ecosystems, shaped by climate and geography. From frigid tundra to lush rainforests, each biome has unique plant and animal life adapted to its conditions. Understanding these biomes is key to grasping Earth's biodiversity and ecological processes.

This section dives into the characteristics of major terrestrial biomes. We'll explore how temperature, precipitation, and seasonality influence the distribution of plants and animals. We'll also look at the fascinating adaptations that allow organisms to thrive in their specific environments.

Terrestrial Biomes

Arctic and Subarctic Biomes

• Tundra biome characterized by extremely cold temperatures, low precipitation, and permafrost soil
  • Vegetation consists of low-growing plants such as mosses, lichens, and dwarf shrubs (sedges, willows)
  • Animals adapted to harsh conditions include caribou, musk oxen, and Arctic foxes
• Taiga biome, also known as boreal forest, located south of the tundra with cold temperatures and higher precipitation
  • Dominated by coniferous trees such as spruce, fir, and pine
  • Fauna includes moose, lynx, and snowshoe hares

Temperate Biomes

• Temperate deciduous forest biome characterized by moderate temperatures, distinct seasons, and sufficient rainfall
  • Trees lose their leaves in the fall, including oak, maple, and beech
  • Rich understory vegetation and diverse animal life (deer, squirrels, birds)
• Temperate grassland biome, also called prairies or steppes, features vast expanses of grasses and herbaceous plants
  • Precipitation is lower than in forests, with occasional droughts and fires
  • Grazing animals like bison, antelope, and rabbits are common

Tropical Biomes

• Tropical rainforest biome found near the equator with high temperatures, abundant rainfall, and incredible biodiversity
  • Multi-layered forest structure including emergent, canopy, understory, and forest floor layers
  • Examples include the Amazon rainforest and the Congo Basin
• Tropical savanna biome characterized by a mix of grasses and scattered trees, with distinct wet and dry seasons
  • Vegetation adapted to survive long dry periods and frequent fires
  • Large herbivores (elephants, giraffes) and predators (lions, cheetahs) are iconic savanna species

Dry and Mediterranean Biomes

• Desert biome defined by extremely low precipitation, high temperatures, and sparse vegetation
  • Plants adapted to conserve water, such as cacti and succulent plants
  • Animals include reptiles, small mammals, and insects (rattlesnakes, kangaroo rats, scorpions)
• Mediterranean scrub biome found in regions with mild, wet winters and hot, dry summers (California, Australia, Mediterranean Basin)
  • Vegetation consists of drought-resistant shrubs and small trees (chaparral, maquis)
  • Frequent wildfires play a role in shaping the landscape and plant adaptations

Biome Characteristics

Climate Factors

• Temperature and precipitation patterns are the primary determinants of biome distribution
  • Variations in solar radiation, latitude, altitude, and ocean currents influence temperature
  • Precipitation affected by atmospheric circulation patterns, proximity to water bodies, and topography
• Seasonality, the annual cycle of temperature and precipitation, shapes the adaptations of plants and animals
  • Distinct growing seasons in temperate biomes, while tropical biomes may have wet and dry seasons

Vegetation Adaptations

• Plants adapt to the specific climate and soil conditions of their biome
  • Tundra plants are small, slow-growing, and able to withstand freezing temperatures
  • Desert plants have water-conserving features like thick cuticles, small leaves, and deep root systems
• Leaf structure and function vary across biomes
  • Broad, thin leaves in tropical rainforests maximize photosynthesis in low-light conditions
  • Needle-like or small, waxy leaves in taiga and Mediterranean scrub reduce water loss

Animal Adaptations

• Animals exhibit morphological, physiological, and behavioral adaptations to their biome
  • Thick fur and insulating fat help Arctic animals retain heat
  • Light-colored coats reflect sunlight and provide camouflage in deserts and tundra
• Migration and hibernation are common strategies for coping with seasonal changes in resource availability
  • Many temperate forest birds migrate to warmer climates during winter
  • Some mammals, such as bears and ground squirrels, hibernate to conserve energy during cold periods