Tundra Biome
There are two types of tundra: Arctic and Alpine. The Arctic tundra encompasses the north pole and ranges south until it reaches the tiaga, a forest area in the Northern Hemisphere. Though seemingly barren, about 1,700 varieties of plants, resistant to the cold, grow in these regions. The high altitude, mountainous regions of the world, where trees cannot grow, are known as the Alpine tundra. Animals that live within the tundra biome have adapted to cold temperatures; instead of fighting for food during the winter, some hibernate during the cold months. Others join the southward migration and move to warmer climes when the tundra weather is frigid.
Desert Biome
The desert biome contains four major types of deserts: hot and dry, coastal, semiarid and cold. Deserts typically receive less than 50 cm, or 19.7 inches, of precipitation per year. Hot and dry deserts have the least rainfall, with the precipitation sometimes evaporating before it ever hits the ground. The dominant animals in these areas are burrowers and nocturnal creatures. The tundra and desert biomes, though at opposite extremes, share a few similarities.
Harsh Environments
Both the tundra and desert biomes have harsh, somewhat hostile environments. The plant life that grows in these environments are usually low to the ground, whether to deal with the frigid winds of the tundra or the low moisture of the deserts. Trees and other canopy plants are rare in both areas.
Extreme Temperatures
The Arctic tundra can reach temperatures of minus 30 degrees Fahrenheit during an average winter. At the other extreme, the hot and dry desert biome can reach a high temperature of 120 degrees Fahrenheit and a low of minus 40 degrees Fahrenheit.
Low Species Diversity
Though there is not a wide range of plant or animal species diversification in either the desert or the tundra biomes, what is there has learned to adapt and to thrive. Some animals and other life forms in each area adapt themselves to the environments by either accelerating or delaying their life cycles in a bid to ensure the young can reach maturity.