Altitudinal zonation of bryophytes on the Huon Peninsula, Papua New Guinea : a floristic approach, with phytogeographic considerations

The study is based on the major part of the bryophyte material collected during the Koponen-Norris expedition on the Huon Peninsula, Papua New Guinea, in 1981. Only taxa which were collected at least twice are included. Five altitudinal zones, the boundaries of which are indicated by discontinuities in the bryophyte flora, are distinguished: 0 - 300 m, 300 - 1200 m, 1200 - 2200(-2300) m, 2200(-2300) - 2800(- 2900) m, and 2800(-2900) -3400 m. These zones, each characterized by a typical species assemblage, are well in accordance with some earlier New Guinean zonation schemes based on the phanerogamic flora and vegetation. The most obvious correlations between bryophytes’ altitudinal ranges on the Huon Peninsula and their general phytogeography are: New Guinean or Western Melanesian endemics, as well as Malesian endemics, are concentrated at relatively high altitudes (zones III-V); Asian - Oceanian and Asian - Oceanian - Australian taxa, notably mosses, are relatively strongly represented at low to moderate altitudes (zones I-III); species which have their main distribution in the northern hemisphere occur at high altitudes; 'cosmopolitan' species either have wide vertical ranges or are restricted to high altitudes