| Heath Forest (HF) |
The tree canopy averages between 5 and 30 meters tall, but is fairly homogeneous in a particular area. There are few big lianas, but many slender ones. Trees of the family Myrtaceae usually predominate. |
| Ultramafic Forest (UF) |
UF varies greatly in structure and species composition, but is usually dominated by species rare or absent from other nearby forests. On hill slopes, UF tends to have a very even rather low canopy in comparison with DF. The only common factor in all UF is that it develops on soils derived from ultramafic rock. |
| Dipterocarp Forest (DF) |
The original DF is tall forest which is characterized by the presence of a fairly high biomass density of large trees of the family Dipterocarpaceae, and often Leguminosae and Lauraceae. The original DF has been very heavily disturbed and nearly all of plants in DF are secondary growth of different species composition from that in the original forest. |
| Freshwater Swamp Forest (FSF) |
Plant species composition in FSF varies greatly, and may be locally diverse, or dominated by one species. The tree canopy is generally rather open, but with extensive patches of low scrub in the most poorly-drained areas. |
| Mangrove Forest (MF) |
Mangrove is characterized by a relatively few species of trees growing in coastal areas inundated with seawater. Nipah is a palm, which forms pure species stands where salt and fresh water mix. |
| Peat Swamp Forest (PSF) |
The structure of PSF varies greatly, ranging from low, stunted vegetation to forest resembling DF. Floral composition is equally variable. The habitat is characterized by a layer of peat (slightly decomposed plant material), 0.5 to over 20 m deep developed on marine alluvium. |
| Palm Oil Plantation (POP) |
POP's are planted on a large scale with species of palm tree, for the purpose of producing oil palm. Most of the DF has been replaced by POP in Sabah especially in the south-eastern part. |
