The largest island of the tropical E-Asian archipelago, 6° S of the equator is also the most mountainous. Jaya Peak (5031 m) on the Indonesian side reaches 5000 m, Mt. Wilhelm on the Papua New Guinea side 4450 m. The trade winds envelope these mountains in clouds for most of the time. Precipitation is massive, exceeding 3000 mm near treeline. The climate is completely non-seasonal, with year round temperatures of about 5.5 °C at treeline, which is at c. 3800 m. Snow and hail can occur at any time of the year. The dominant tree species at the treeline are Ericaceae and Asteraceae, the treeline areas and moorlands are dominated by tall tussock grasses.

1 - A rare moment with no fog shortly before sunset at Lake Pindaunde (Mt. Wilhelm region, 3500 m).

2 - Dimorphanthera sp. (Ericaceae) (Mt. Wilhelm, 3500 m)

3 - Vaccinium sp. (Ericaceae) (Mt. Wilhelm, 3500 m). Rhododendron and Vaccinium (both Ericaceae) species are abundant both in the forest and on moorlands in the upper montane belt.

4 - Rhododendron sp. (Ericaceae) (Mt. Wilhelm, 3500 m). Rhododendron and Vaccinium (both Ericaceae) species are abundant both in the forest and on moorlands in the upper montane belt.

5 - Tetramolopium sp. (Asteraceae) (Mt. Wilhelm, 4420 m). See also Hawaii.

6 - Since skies clear during most nights, there is regular freezing. Here Potentilla sp. (Rosaceae) leaves with frost.

7 - Open tussock grassland and dwarf shrubs (Mt. Wilhelm, 4420 m).

29 August 2011
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