Biosphere Contents

6. Biomes

The opinions of ecologists differ as to the exact definition of biome, and how many there are

According to Botkin and his colleagues (1986) "a biome describes a set of ecosystems within a geographical region exposed to the same climatic conditions and having dominant species with a similar life cycle, climatic adaptations and physical structure." This definition emphasises the importance of climatic factors (notably precipitation and temperature) in defining a biome. More recently, the World Wide Fund for Nature have developed an ecological land classification in which they list 14 biomes, defined by climate and vegetation type, and also called 'major habitat types'. These lie within 8 ecozones, which are defined geographically (i.e. by continent).

How temperature and precipitation determine the distribution of biomes

According to Odum (1971): "a biome is the largest land community which it is convenient to recognise." Although this definition mentions only terrestrial ecosystems, aquatic biomes can also be distinguished in similar terms.

How does Botkin's definition of a biome differ from that of Odum?