Distribution

Recorded from southernmost peninsular Thailand; Peninsular Malaysia, Indonesia: Kalimantan, Maluku [Moluccas] (Obi &Waigeo Islands), Philippines, Singapore, Sulawesi, Sumatera (Bangka & Belitung Islands); and Papuasia: New Guinea (Papua (Irian Jaya): Vogelkop Peninsula).

Habitat and Ecology

This species occurs primarily on sandy beaches and bluffs, often on the land side of mangrove thickets at or just above the high tide mark. It can even occur within the mangroves on slightly raised, sandy ridges (probably old beaches). Here it is a stunted tree not exceeding 6-7 m in height. On coastal limestone and granitic rocks the trees are gnarled and shrubby, not exceeding 2-3 m. A second important habitat is coastal lowland 'kerangas', a low forest on almost pure sand, and 'pandangs', i.e. degraded heath forest; in these vegetations Myrtaceae have an important presence besides the conifers. In the interior of Peninsular Malaysia, the Philippines, and elsewhere it occurs on limestone hills and plateaus at altitudes between 150 m and 550 m (in Palawan at ca. 1,000 m) a.s.l. Here trees may be taller; in Obi (Moluccas) trees are reported to reach 40 m tall with slender, buttressed boles clear of branches to 25 m. This can only occur in competition with other tall forest trees, where P. polystachyus is striving to reach the canopy. It appears therefore to be a highly adaptable species and the nearest to a mangrove-inhabiting conifer in existence.

Conservation Status

Global status

Vulnerable A4ac

This species, perhaps due to its very wide distribution, has formerly been assessed as Least Concern. However, its occurrence in habitat that is rapidly being altered or destroyed over wide areas to make way for oil palm plantations, poses a threat formerly insufficiently recognized. It is estimated that the decline will be at least 30% by 2020, with 1980 as an approximate starting point for the widespread conversion of its habitat. It is very likely that this species may meet criteria for an even more threatened category than Vulnerable, but more information is required before it can be upgraded.

The main threat to this species is the rapid and widespread deforestation that occurs in the low lying coastal areas of Peninsular Malaysia, Borneo and the Philippines, primarily to make way for oil palm plantations. There can be no doubt that this has caused and is still causing a decline in area of occupancy (AOO) but only a detailed study across the wide range of this species would give us some accurate estimates of rates of decline. There are also records from upland and sometimes remote locations that are not affected to the same degree with deforestation, and the species has a very extensive extent of occurrence (EOO). Despite this, and given the length of the generation time, it is likely that the total reduction in past and present will exceed 30%.

Conservation Actions

Only a small percentage of known localities of this species are currently situated in protected areas, notably on the island of Palawan in the Philippines. A survey of existing locations with this species still undisturbed along the northern coast of Borneo and in Peninsular Malaysia is urgently needed, and protected areas established where possible.