ABSTRACT
This chapter considers the major biomes in turn, starting with the terrestrial low-productivity systems and moving up the productivity scale to the tropical forests. The most extensive ecosystem unit which it is convenient to designate is called the biome. This consists of a dominant life-form which extends over an area that corresponds to a particular distribution of soil types and climate. Thus, although the species of tree or grass may vary from continent to continent, it is possible to recognise the deciduous forest or grassland biome in each. The tundra has sometimes been called an ‘Arctic desert’ and it shares some characteristics with the biome, including a distinct vulnerability to human activity. The tropical savanna, the first tropical biome to be considered, is in many ways intermediate between a forest and a grassland and indeed the term has been applied to a variety of vegetation formations from a nearly closed canopy woodland to a grassland with thinly scattered bushes.
