**5. Tropical rainforests: Malaysia's perspective**

The tropical rainforest in Malaysia is one of the most diverse, complex, and productive terrestrial ecosystems in the world. The climate of Malaysia is typically humid tropical and is characterized by year-round high temperatures and seasonal heavy rain. As a result of these climatic conditions, the predominant natural vegetation is tropical rain forest whereby the main forest types being lowland then hill dipterocarp forest, peat swamp forest, freshwater swamp forest, and mangrove forest [35]. Malaysia has a total land area of 32.86 million ha. Of the total land area, 20.46 million ha are forest areas in which Peninsular Malaysia, Sarawak, and Sabah cover 28, 45, and 27% of the total forest areas, respectively [13]. It was estimated that Malaysia forests in Peninsular and Borneo are about 2830 and 9000–15,000 tree species, respectively [36, 37].

## **5.1 Species composition**

Malaysian tropical rainforest is a productive forest which consists of various valuable timbers from the family of dipterocarpaceae and non-dipterocarpaceae. The name "dipterocarp" comes from the Greek for "two-winged seed." The

dipterocarp species are from the family dipterocarpaceae and are the giants of the South-East Asian forests as well as the dominant family in them. Dipterocarp trees dominate forests in Borneo, Sumatra, Java, Peninsular Malaysia, and the wet parts of Philippines. The largest genera are *Shorea* (196 species), *Hopea* (104 species), *Dipterocarpus* (70 species), and *Vatica* (65 species). Other common genera namely *Dryobalanops*, *Neobalanocarpus*, *Parashorea*, *Cotylelobium*, and *Anisoptera* are also important part of tree communities of tropical rainforests. It is common to find 25 or more species of *Shorea*, and six or more species of the other three genera in the forest of Peninsular Malaysia, Borneo, and Sumatra. Dipterocarp trees have excellent timber qualities, and they are marketed internationally as plywood and as sawn timber [38].

Non-dipterocarps consist of 427 species from 201 genera and 50 families of nondipterocarps. Examples of important non-dipterocarp families are Leguminosae, Myristicaceae, Euphorbiaceae, Burseraceae, Sapotaceae, and Apocynaceae. Unlike dipterocarp species, generally non-dipterocarp timbers are less durable than the dipterocarp. However, according to Schulte [39], the non-dipterocarp species also play an important role within the tropical rainforest. They either form the major components of the understory layer (i.e., Annonaceae, Euphorbiaceae, Lauraceae, Meliaceae, Myristicaceae, and Rubiaceae) or they have the commercial use, frequently only locally as fruit trees (i.e., Moraceae, Anacardiaceae, Bombacaceae, Euphorbiaceae, Guttiferae, Lauraceae, Mimosaceae, Polygalaceae, and Sapindaceae).
