Wetlands of Sumba Island
Location:
9°40'S, 120°00'E; East and West Sumba Districts, Sumba, East Nusa Tenggara. The main freshwater lakes are on the north coast of the island, 30 km east of Waingapu (9°39'S, 120'23'E).
Area:
Area of wetlands unknown; island 1,100,000 ha.
Altitude:
Sea level to 1,000m.
Biogeographical Province:
4.23.12.
Wetland type:
05, 07, 08 & 14.
Description of site:
Much the most extensive wetlands on Sumba Island are mangrove swamps, which cover almost 5% of' the land area. Several mangrove areas have been identified as being of conservation interest and of importance to the local coastal fisheries. The southern part of the island is hilly, with a number of small fast-flowing rivers. Much of the north coast is low-lying, and there are several small lakes in natural depressions, particularly in the northeast. The most important of these is at Kadumbal, at the edge of a coralline plateau 30 km east of Waingapu. This is a complex of shallow, freshwater lakes and extensive reed-beds covering an area of 25-35 ha, and surrounded by overgrazed pasture, rice paddies and arable land. The lakes are fed by local run-off, and apparently dry out during the middle of the dry season (from June or July onwards).
Climatic conditions:
Dry tropical climate, with most rain falling in January-March. The highest hills are moist, but the rest of the island is rather dry.
Principal vegetation:
Mangrove forest with species of Avicennia, Sonneratia and Bruguiera reed-beds and sedge marshes around freshwater lakes in the north. Dominant plant genera elsewhere on the island include Asplenium, Plazycerium, Bulbophyllum, Dendrobium, Vomda. Selaginella, Begonia, Pal aquium, Podocarpus and Amorphophallus.
Land tenure:
Mainly state owned; the Indonesian Government owns all land not proven to belong to a given individual or group.
Conservation measures taken:
None.
Conservation measures proposed:
The Mount Wanggameti and Laiwanga area has been proposed as a Game Reserve (5,000 ha). This would include some coastal mangrove areas.
Land use:
The mangrove forests are quite heavily exploited by the local people for firewood and timber for boat-building. There is some fishing, hunting and livestock grazing at the freshwater lakes and marshes in the north, and rice-growing and other agriculture in adjacent areas.
Disturbances and threats:
Illegal grazing, shifting cultivation and excessive wood-cutting. Hunting may cause a considerable amount of disturbance at the lakes.
Economic and social values:
The mangroves are of considerable importance in maintaining the local fishery, and also provide firewood, charcoal and timber. The freshwater marshes are an important dry season refuge for domestic livestock. Freshwater wetlands of the type found on the north coast of Sumba are rare in Wallacea; consequently the Sumba wetlands, although small, are of considerable scientific interest and conservation value.
Fauna:
No information is available on the birds of the mangrove areas. Waterbirds observed~ by Bishop (in prep) during a brief survey of Kadumbal Lake included:
10 Tachybaptus ruficollis 10 Ardea purpurea (breeding)
300 Dendrocygna arcuata 10 Porphyrio porphyrio
25 Chlidonias hybrida
along with smaller numbers of Phalacrocorax sulcirostris, P. melanoleucos, Pelecanus conspicillatus, Ixobrychus cinnamomeus, Ardeola speciosa, Egretta garzetta, E. intermedia, E. alba, Ardea novaehollandiae, Plegadis falcinellus, Pandion haliaetus, Anas gibberifrons, A. superciliosa, Himantopus leucocephalus, Pluvialis dominica and Calidris ferruginea. The observations of I. cinnamomeus, P. falcinellus, H. leucocephalus and C. hybrida were the lint records of these species on Sumba. Stiltia isabella was found to be common and widespread throughout the grasslands. Other birds recorded from the island include Megapodus reinwardá Actitis hypoleucos and the kingfishers Halcyon chioris and H. sancta. Mammals known to occur on the island include Macaca fascicularis, Cervus timorensis and Sus scrofa.
Special floral values:
Two rare species of plant, Mamilkara kauki and Santalum album, occur on the island, but are now virtually extinct. Two plants with edible tubers, Dischorea ip and Amorphophallus companulatus, are of local importance.
Research and facilities:
K.D. Bishop has conducted a preliminary avifaunal survey of Kadumbal Lake.
References:
Bishop (in prep); FAO (l982b); MacKinnon & Artha (1982c); White & Bruce (1986).
Criteria for Inclusion:
1b, 2b, 3b.
Source:
K. David Bishop, Agustinus W. Taufik and Edi Djuharsa.