Java and Associated Islands,
Biodiversity and Tropical Forests in Indonesia.

Java, with an area of 130,000 km², which is slightly larger than New York State, has two large associated islands, Madura (5,672 km²) and Bali (5,560 km²). Java and Bali have 20 volcanoes that have been active in the past, making them the most volcanically active islands in the world (van Bemmelen 1970). These volcanoes impact the biodiversity of these islands enormously, creating as they do the highly fertile alluviums that once sustained enormous forested areas and now the high density of humans. In the recent past, volcanoes also dramatically changed the surface landscapes and altered river flows in both Java and Bali (Bennett and Bennett 1980).

In 1995, Java had a population of 114 million people living at an average density of 862 people/km². This high density of people is a result of historical influences and the high fertility of its volcanic soils, which lend themselves to terracing for irrigated rice farming. Nearly 200 years ago, the Dutch colonial office described Java as being overcrowded (van der Kroef 1956).

Some 15% of Java is ‘critical land’ subject to serious soil erosion, a fact recognized by the Dutch. The average loss of soil on agriculture land has been estimated at 123 tons /ha/year (World Bank 1990). Farming on uplands, particularly intensive farming of vegetables, clearing of trees from uplands and lack of consistency in applying expensive terracing has resulted in a recent increase in erosion, flooding and landslides that have resulted in significant loss of human life.
Next >>>