Identify Earth's major biomes from their climate and vegetation characteristics and explain why biomes correlate with latitude and climate.
A biome is a large region defined by its climate and the plant and animal communities adapted to survive there. Because climate is the main force shaping which plants can grow and which animals can thrive, biomes tend to form broad bands connected to latitude and climate pattern rather than to political borders -- the same biome can appear on different continents wherever the climate matches.
Tropical rainforests hug the equator, hot and rainy all year, hosting more species than any other biome despite surprisingly thin, nutrient-poor soil. Deserts, found both near 30 degrees latitude and in continental interiors and rain shadows, receive less than about 25 centimeters of rain a year and swing between extreme heat and cold. Grasslands and savannas have a wet and dry season rather than rain all year, favoring grasses over trees. Temperate forests, in the mid-latitudes, experience four real seasons and are dominated by deciduous trees that drop their leaves each fall. The taiga (boreal forest), found across a wide band of Canada and Russia, is cold with long winters and is dominated by cone-bearing evergreen trees. Tundra, found near the poles and atop high mountains, stays so cold that the subsoil remains permanently frozen (permafrost), limiting plants to mosses, lichens, and low shrubs.
Mastery looks like: Given a short climate and vegetation description, they can correctly name the biome and explain the climate reasoning behind their answer.
Common stumbles: Confusing savanna with true grassland or with rainforest; assuming rich vegetation always means rich soil, which tropical rainforests disprove.