Geoscience Reference
In-Depth Information
Figure 3.17 Rainforests of Sumatra stretch over the mountains but are rapidly being
destroyed. Taken in Gunung Leuser National Park, Aceh Province, Sumatra, Indone-
sia.
(Photo courtesy of Gareth Bennett.)
flowering plant families present are the gingers, sedges, aroids, African violets, and
orchids. Fern-like spiked mosses occur in the understory and on the forest floor.
Dipterocarpaceae
The rainforests of West Malesia are like no others in the world because of the dom-
inance of a single family, Dipterocarpaceae. The family name means ''two-winged
fruits,'' which describes the appearance of their fruits that come in many different
sizes and shapes. Tens of genera and hundreds of species are found almost exclu-
sively within this region. Dipterocarps have been present for a very long time. Dip-
terocarp pollen found in this area has been dated to 30 mya, a time coinciding with
the collision of the Indian plate with Asia. Dipterocarps are thought to have origi-
nated in Africa and reached Southeast Asia via the migrating Indian plate. They
then underwent a massive evolutionary radiation in Southeast Asia. The later colli-
sion of the Australasia plate with Asia may have allowed the dipterocarps to dis-
perse into Sulawesi and the Pacific region. Dipterocarps dominate the forests of
Borneo, Java, Sumatra, and the Malay Peninsula and the wetter forests in the
Philippines.
