- a large ecological region defined by distinct climate zone, flora, and fauna
- major terrestrial biomes: tropical rainforest, savanna, desert, temperate forest, taiga/boreal, tundra, grassland
- aquatic biomes: coral reef, open ocean, freshwater, estuary, wetland
- distribution determined by temperature, precipitation, latitude, altitude, and soil type
- each biome hosts characteristic ecology and evolutionary adaptations
- biomes shift boundaries in response to climate change
- biodiversity varies dramatically: tropical rainforest holds over 50% of all species
- the biome concept links atmosphere, water cycle, and carbon cycle to living systems
- human activity converts biomes through agriculture, urbanization, and deforestation