Hobbies And Interests
Climate
The tundra is Earth's coldest biome. Its average temperature is at or below minus 10 degrees Celsius, or 14 degrees Fahrenheit, according to Marietta College's Department of Biology and Environmental Science, based on the work of ecologist Robert Whittaker. Tropical forests, on the other hand, have average temperatures between 20 and 30 degrees Celsius, or 68 to 86 degrees Fahrenheit. Whittaker's famous diagram of biomes relies on average temperature as one of the two key factors; the other is precipitation. Tundras tend to be drier than tropical forests; they experience, at most, 100 centimeters, or about 40 inches, of precipitation in a year. Tropical forests experience between 150 to 250 centimeters, or 60 to 98 inches, for a seasonal forest and 250 to 400 centimeters, or 98 to 157 inches, for a rain forest, the wettest biome.
Location
A biome's geographical location greatly affects its climate. Tundras lie in the far north, between the arctic ice cap and the cool, forested taiga. This region includes much of Alaska and Siberia, as well as northern Canada and Europe. This northern location means that the tundra is dark for much of the winter. Tropical forests, however, by definition lie between the two "tropics," which lie at 23 degrees 5 minutes north latitude and 23 degrees 5 minutes south latitude. Thus, tropical zones are at and near the equator, a position which gives them strong, direct sunlight year-round.
Plant Life
The warm weather and plentiful rainfall of tropical forests result in incredible diversity of plant life, especially in the lush, moist rain forests. Here, NASA's Earth Observatory: Mission Biomes project explains, you will find "dense canopies of vegetation that form three different layers," namely, the canopy, understory and floor. Immense trees and the vines they support tower in the canopy, 250 feet high, and the shady understory is home to many of the plants recognizable as houseplants, such as palms, ferns and orchids. The floor, meanwhile, is a constantly replenishing compost pile in which the dense vegetation decomposes into the many nutrients needed to support the vast ecosystem above. In contrast, the tundra may appear to be nearly lifeless, almost entirely lacking trees. In fact, the word "tundra" comes from a Finnish word meaning "treeless plain." While the tundra lacks the vivid biodiversity of the forest, it is by no means lacking in plant life altogether. Here you will find a variety of mosses, lichens and liverworts, along with tough, low shrubs and grasses. There are even flowers here -- some 400 species in the tundras of the world, according to an estimate by the University of California's Museum of Paleontology.
Animal Life
Tropical forests have similarly rich and diverse animal populations, though the fauna can not compare in numbers or variety with the flora. Among the animals that call tropical forests home are birds, bats, small mammals and insects and spiders, along with amphibians, reptiles and other invertebrates. The tundra has fewer animals, but they are highly adapted to the cold, dry conditions; tundra creatures include small mammals (voles, arctic foxes, lemmings), large mammals (caribou, polar bears), migratory birds and even insects.