A Biome is all of the life zones, all plants, animals, and other organisms, as well as the physical environment in a particular area. A biome is characterized by its plant life, which is determined by its location. For example, northern coniferous forests exist in sub-arctic portions of North America and Asia, but further north, the conditions are simply too harsh and the season too brief for trees to grow. Instead of trees, the short vegetation of the tundra thrives in these areas. The same occurs with altitude, as trees give way to short alpine vegetation in high mountainous regions.
A biome is composed of many ecosystems, which are smaller communities of plants and animals and their habitats, the physical parts of their environment that affect them. Whereas, the boundaries of a biome are determined by climate, the boundaries of ecosystems are physical features, such as ridges or riverbanks, which separate one community from another.
Any given place may have several different ecosystems that vary in size and complexity. A tropical island, for example, may have a rain forest ecosystem that covers hundreds of square miles, a mangrove swamp ecosystem along the coast, and an underwater coral reef ecosystem. No matter how the size or complexity of an ecosystem is characterized, all ecosystems exhibit a constant exchange of matter and energy between the biotic and abiotic community.
The ecosystems of a particular biome tend to have plants with similar growth forms and animals with similar feeding habits. Major biomes include tropical rain forest, northern coniferous forest, tundra, desert, grassland, savanna, and chaparral.
The tropical rain forest is the most complex biome in the world. This biome is found at low elevations in the tropics where it is always warm and wet. Rain forests are characterized by a dense tree canopy...