South Malesian BioProvince
This BioProvince (as defined by Armen Takhtajan) comprises the islands of Java, Madura, Babor, Damar, the Lesser Sunda Islands (Nusa Tenggara) including Kangean, Bali, Lombok, Sumbawa, Sumba, Flores and Timor together with Christmas Island some 300 km south of Java. Geologically the area is complex and varied. Java consists of Tertiary and Quaternary volcanics, and uplifted coral limestone. It is thought to have formed during the Miocene some 24 million years ago as a result of subduction processes associated with Australian-Indian Ocean and Eurasian tectonic plates in the area now know as the Java Trench. The Lesser Sunda Islands, on the other hand, represent two geologically distinct archipelagos. Bali, Lombok, Sumbawa, Flores and Wetar form a volcanic northern archipelago which developed during the Pliocene some 15 million years ago when the Australian and the Asian tectonic plates collided although Bali may not have emerged from the sea until about 3 million years ago. The southern archipelago including Sumba, Timor and Babar is non-volcanic and probably part of the Australian Plate. Different again is Christmas Island, which is the summit of a submarine mountain (seamount) of volcanic origin rising some 5000 m from the seabed. It surfaced about 60 million years ago giving rise to a coral atoll. Over time the atoll appears to have sunk but slowly enough for coral limestones to continue building. Then about 10 million years ago the island began to emerge as a series of uplifts and the atoll’s lagoon eventually drained becoming a central plateau. The climate is also relatively complex straddling both tropical wet and tropical dry climatic zones. Java is hot and humid for most of the year with heavy downpours particularly when the western monsoon arrives between October and April, while the Lesser Sunda Islands experience a tropical dry climate, which has given rise to vegetation that is strikingly different from that of the rest of the Indonesian archipelago. The flora is not particularly rich compared with other Malesian islands but it does include four endemic genera: Grissaea (Apocynaceae), Sclerachne, Teyleria (Acanthaceae) and Septogarcinia (Clusiaceae). Species endemism is likewise comparatively poor.
The following accounts for this BioProvince have been written or will be written with particular reference to endemic and locally important species. Accounts available are displayed in green or yellow. Those displayed in red are either in the pipeline or awaiting expert contributions.
|Endemic Vascular Plant Flora|
|Endemic Flora Christmas Island|
|Endemic Flora (Java)|
|Endemic Flora (Lesser Sunda Islands)|