Hill Mixed Dipterocarp Forest

 It is widespread, covering more then 80% of Sarawak's natural forest area. The Hill Mixed Dipterocarp Forests are richly diversified and contain the greatest number of economically important trees. These include Meranti (Shorea spp.), Kapur (Dryobalanops spp.), Keruing (Dipterocarpus spp.) and Mersawa (Anisoptera spp.) which are highly prized as timber.

The hill mixed dipterocarp forest is non-homogeneous and five canopy layers can be identified, as shown in the diagram. The top most layer comprises the biggest trees that reach to 60 metres in height, standing out singly or in clusters above a continuous second layer that reaches up to 45 m.

Below this level is an under-storey of 23 to 30 m tall trees that sometimes intermeshes with the main canopy. Shorter woody treelets and shrubs form the fourth strata while the last layer is found on the forest floor which is carpeted with herbs and seedlings.

Because of the very nature of forest dynamics, the canopy is very tightly knitted since gaps (resulting from lightning strikes or the falling and decay of over-mature trees) are rapidly filled with sprouts of saplings and seedlings. The result is a tangled web of greenery wherever you go in the forest.