Abstract

Plant species diversity is greatest in tropical forest. The highest plant species density yet recorded, 365 species in just 1000 m², is for the only complete enumeration of tropical forest plants (Gentry and Dodson 1987). The diversity of lowland tropical forest at a local scale may exceed the diversity of extratropical forests at a continental scale. The combined temperate forests of Europe, North America, and Asia support 1166 tree species in 4.2 x 10⁶ km² (Latham and Ricklefs 1993). In contrast, 1175 tree species occur in just 0.5 km² of lowland dipterocarp forest in Borneo (LaFrankie 1996). Trees comprise just 25% of the plant species in tropical rain forests (Gentry and Dodson 1987). There are 65% of all flowering plant species, 92% of fern species, and 75% of moss species that are tropical (Prance 1977).