Montane

 

Montane forests can be observed in high elevation landscapes starting around 750 meters above sea level. This forest is also called mossy forest since the trunk and branches of trees are draped with mosses, liverworts, and lichens. Many plants have small thick leaves which compose slowly, especially at lower temperatures. As a result, the organic litter accumulates; releasing little of its nutrients, and plant growth is slow.

Montane forests in Brunei Darussalam can only be found in Temburong district. They are categorized into lower montane and upper montane types.

Mixed Lower Montane Forests

Mixed lower montane forests occur at elevations ranging 910 meters to 1,280 meters above sea level. Soils characteristics are sandy loam and clay, with a development of a thin "mor" layer on the ridge. Vegetation is moderately dense and composed of small to medium-size trees. Some dipterocarps are still present mixed with oaks or 'mempening' (Lithocarpus spp., Quercus spp.) along with 'nyatoh' (Madhuca spp., Palaquium spp., and Payena spp.). The existence of the gymnosperm Podocarpus neriifolius can also be observed in the association.

'Tulong' Association

The montane forest can be found on broad ridges with moderate slopes with an elevation of between 700 to 1,220 meters above sea level. The forest is predominantly occupied by 'tulong' (Agathis endertii) in relatively sandy soil of medium depth, fine-textured, and with a thin mor layer.

Shorea coriacea Mix

This forest mix can be found in localised areas and limited distribution between 910 to 1,100 meters elevation.  The soil structure is the same as the 'tulong' type but occupied by two major species; 'meranti tangkai panjang' (Shorea coriacea) and 'tulong' (Agathis endertii) , The two species do not overlap, with S. coriacea dominating the forests and occupying the ridges with shallow sandy soils that are probably highly leached.

Oak Forest (Upper Montane - Tall Facies)

The forest structure is comprised mainly of branchy small trees (rarely exceeding 40 cm diameter), and found on very steep terrain between 1,200 and 1,550 meters elevation. The soils are peaty and covered with a moss layer. The understorey is dense and difficult to penetrate.

Rhododendron Mix (Upper Montane - Short Facies)

The uppermost forest structure in Brunei Darussalam is found in elevations ranging from 1,070 to 1,830 meters. Soils are skeletal with an exposed peaty surface layer. Dense low vegetation includes such as Dacrydium beccarii, Phyllocladus hypophyllus, Syzygium bankase, and Calophyllum nodosum. Rhodoendrons, are widespread and abundant. Pitcher plants are well adapted in these forests and abound on forest floors, on shrubs or even in the crown of trees. Pitcher plant species or 'sumboi-sumboi' such as Nepenthes tentaculata and N. stenophylla can be observed in lower elevations while N. lowii in higher elevations.