The biosphere is the zone of the Earth where life exists; a biome is a large regional community of plants and animals adapted to a particular climate, such as a tropical rainforest or a desert.
- The major terrestrial biomes, broadly from equator to pole, are tropical rainforest, tropical savanna (grassland), hot desert, Mediterranean scrub, temperate grassland (prairie, steppe, pampas, veld), temperate deciduous forest, boreal forest (taiga), and tundra.
- Climate, mainly temperature and rainfall, is the chief control on which biome develops; the tropical rainforest (such as the Amazon and Congo) is the most biodiverse.
- Temperate grasslands have regional names: prairies (North America), steppes (Eurasia), pampas (South America), veld (South Africa), and downs (Australia); they are the world's great grain and grazing lands.
- The taiga (coniferous boreal forest) is the largest land biome by area; tundra, beyond it, is cold, treeless, and has permafrost.
- Within a biome, energy flows through food chains and webs, and matter cycles through biogeochemical cycles; an ecosystem is a smaller functional unit.
The sequence of biomes by climate, the named temperate grasslands (prairie, steppe, pampas, veld), the rainforest as most biodiverse, and the taiga and tundra are recurring world-geography facts.
Biome (large climate-defined community) versus ecosystem (smaller functional unit) versus biosphere (all life); savanna (tropical grassland) versus prairie and steppe (temperate grasslands); taiga (coniferous forest) versus tundra (treeless, permafrost).
Climate-defined regional life zones from rainforest to tundra; temperate grasslands are prairies, steppes, pampas, and veld.