Terrestrial (2) - Java and Associated Islands,
Biodiversity and Tropical Forests in Indonesia.

Lowland Rainforests in Java (and Bali) do not have one dominant species or one dominant family of plants, and the variability in species composition is such that no typical assemblage can be described. However, four dominant species are common. These are Artocarpus elasticus, Dysoxylum caulostachyum, Langsat (Lansium domesticum) and Planchonia valida (Kartawinata 1975). The deciduous forests of Java and Bali occur where there are four or more dry months. These forests contain only a few of the species found in lowland forests; one of the few emergents is Salmalia malabarica. Deciduous forests may be found near Indramayu, Madura where fragments still exist; near Pagantenan and Baluran National Park, which mostly consists of this vegetation; and eastern and western Bali. Nothing is known of the fauna of these forests. Virtually all forests on limestone have been lost on Java. But apparently no species of plant was restricted to these forests (van Steenis 1931).

Swamp forests have all but disappeared from Java and may never existed on Bali. It is estimated that they once covered an area of 72,000 ha, but that now only 7,700 ha remain (Whitten et al. 1996). They were generally formed in depressions of volcanoes or behind riverbanks. Little has been written on the fauna of these Javan swamps.

Mountain forests show similar vegetation to that described for Sumatra in this Report. However, the vast array of mountains in Java has provided a natural laboratory to study variation between mountain flora and vegetation. Van Steenis (1972), among others, found that the composition of plant communities can differ significantly between mountains or even neighboring ridges as a result of minor differences in aspect or age of soil. As with other islands, the demarcation between lower mountain and lowland forests is at about 1000 m altitude and is largely floristic. The lower boundary of the Upper Montane Forests in most of Southeast Asia is generally quite abrupt, but on Java there is a gradual change, probably because the volcanic soils are relatively nutrient rich (Whitmore 1984). Lower Montane Forests in Java are characterized by oaks (Lithocarpus and Quercus), chestnuts (Castanopsis) and numerous species of laurels (Fagaceae and Lauraceae) (Mukhtar and Pratiwi 1991). The Upper Montane Forest and Sub-alpine Forest have an assemblage of plants similar to that described for Sumatra.

Java’s mammals, like its flora, are less rich in species than Borneo and Sumatra, but Java does have a high level of mammal endemicity. Its terrestrial mammal fauna consists of 137 species, including 18 rats and mice, and 68 bats (Sody 1989, Kitchener and Maryanto 1993).