Included here are forests on the islands of Java, Madura, Babor, Damar and the Lesser Sunda Islands (Nusa Tenggara) including Kangean, Bali, Lombok, Sumbawa, Sumba, Flores and Timor. These can be broadly divided into mixed rainforest in the lowlands and dipterocarp forests on the mountain slopes

Evergreen Lowland Rainforest

Lowland rainforest in this zone is now largely confined to isolated remnants such as on Nusa Kambanga (an island off the coast of south-central Java). It is a relict forest but still includes rare endemic species such as the giant voodoo lily Amorphophallus decus-silvae (Araceae). Other stands occur at Lebakharjo (a strip of lowland forest on the south coast of east Java) and on Mount Wayang in west Java. However, unlike the lowland rain forest of Borneo and Sumatra where the dominant trees are dipterocarps, most of the lowland forest of Java and other parts of this zone have no dominant species or family and because of their variability no ‘typical’ mix of species can be identified. Nevertheless, certain tree species are more common than others. In the remnant forest of west Java these include Artocarpus elasticus, Dysoxylum caulostachyum, Lansium domesticum and Planchonia valida.

Dipterocarp Forest

On Sumbawa three layered Dipterocarpus retusus forest can be found on the northwestern slopes of Mount Batulante. The first layer mainly comprises giant emergent trees of the leguminous Serianthos minahassae. Its umbrella-like crowns can reach heights of up to 60 m, but no dipterocarps reach these heights. The second layer or canopy is about 40 m high and dominated by Dipterocarpus retusus. Other trees include Cinnamomum culilaban, Platea excelsea and species of Dysoxylum and Elaeocarpus. Many of these canopy trees become festooned with the beard lichen Usnea barbata a feature more usually associated with upper montane forests. Shade-loving trees and shrubs make up much of the third layer including the endemic Archidendron (Abarema) harmsii (Fabaceae) and Septogarcinia sumbawaensis (Clusiaceae). These lower layer trees support a wealth of epiphytic ferns and orchids. The forest floor vegetation is also very diverse with many small shrubs and herbs. Interestingly, dipterocarps are replaced by the Sumbawa endemic Heritiera gigantea (Sterculiaceae) on the drier northern and eastern slopes of Mount Batulante.

References

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