The tropical forests

Abstract

The tropical forest ecosystem is represented by three floristically diverse formations. The American formation is the most extensive, but large tracts of tropical forest are also found in equatorial Africa and South East Asia (Figure 2.1). Throughout these regions there is a recurrent structural and physiognomic adaptation to similar environmental conditions. However, these convergent traits have arisen in very different floras and many species have extremely localized distributions. The most complex communities, described as ‘rain forests’, are associated with the warm, moist tropical lowlands (Figure 2.2). Their multilayered, evergreen canopies provide a mosaic of niches which support a great diversity of smaller plants and animals. This is but one of many tropical forest types, the characters of which are largely determined by differences in temperature and precipitation regimes. At higher elevations where conditions are cooler the trees become smaller (Figure 2.3) and as the canopy begins to open the understory plants become increasingly abundant (Table 2.1).