Tasek Bera
Location:
2°47'-3°09'N, 102°23'-102°47'E; in the southeastern part of Temerloh, north and south of Kg. Datok, State of Pahang.
Area:
Approximately 6,150 ha of wetland in a watershed of 61,383 ha. The area of the proposed Tasek Bera Nature Reserve Park is 26,500 ha.
Altitude:
Swamp less than 30m; watershed 75m.
Biogeographical Province:
4.7.1.
Wetland type:
14 & 21.
Description of site:
Tasek Bern is an alluvial peat swamp ecosystem, measuring 34.6 km at its longest and 25 km at its broadest. The watershed of this swamp lies on the plains between the main and eastern ranges of Peninsular Malaysia, within the 75m contour. The watershed is composed predominantly of argillaceous strata which weather to pale-coloured, firm, heavy textured soils. The swamp lies on a north-south longtitudinal axis, and drains northwards through a single river, the Sungei Bera, a tributary of the Sungei Pahang. The Sungei Bera originates east of the swamp watershed and passes very close to the main channel of the swamp near its outlet near Tanjong Kuin, before draining northwards into Sungei Pahang. Tasek Bern is a dendritic complex occupying extensive sinuous arms of water, and wide areas of reed and swamp forest in between patches of raised ground. A number of streams drain from the high ground into the swamp. More than 75% of the swamp area is occupied by vegetation. The benthic substrate of the swamp is peat, up to 7m deep in the littoral region. The water in the swamp moves at varying speeds, with maximum flow in the limnetic channels. The main channel draining into Sungei Bern is unable to cope with surface flow in the monsoonal seasons, especially the northeast monsoon (September-January), resulting in marked fluctuations in the water level. During these monsoons, especially the northeast monsoon, the Sungei Bera and Sungei Pahang are flooded and cause a reverse flow of water into Tasek Bern through several channels near the main outlet. As a consequence, the water level in the swamp rises between one and five metres during the northeast monsoon. The littoral zone has an average depth of 0.8m, the limnetic region 2.Om, and the channels in the swamp forest 2.5m. The maximum depth in the main channel near the outlet is 7.Om. The pH is low, averaging 5.33 (range 4.57-6.83). The pH is mainly affected by organic solutes derived from allochthonous and autochthonous sources.
Climatic conditions:
Humid tropical climate; the annual rainfall at Dunlop Estate, Bahau, was 1,987 mm in 1970 and 2,763 mm in 1971. 1971 was atypical due to abnormally heavy rains. There are two rainy seasons, in April-May and September-January, and two dry seasons, in February-March and June-August. Apparently the rainfall in the Tasek Bera watershed is patchy and sporadic, being considerably influenced by micro-climatic and local conditions. The mean air temperature is 29.5°C (range 25.2-36.8°C); the mean water temperature 26.3°C (range 23.3-31.2°C).
Principal vegetation:
Tasek Bera is composed of three major habitat types: (I) the limnetic or open water region which is fringed by stands of Utricularia in the surface waters (1% of swamp area); (2) the Lepironia reed and Pandanus clump stands forming part of the littoral region (32% of swamp area); and (3) the Eugenia swamp forest stands which form the major part of the littoral region (67% of swamp area). The algae have been well studied, and 328 species, varieties and forms have been described, of which 293 including 14 unidentified species belong to the Chiorophyta. Of the seven submerged macrophytes, Utricularia flexuosa and Cryptocoryne griffithii are dominant, in association with Blyxa echinosperma. Hydrilla verticillata and Potamogeton malaianus. Twelve emergent macrophytes have been recorded in the littoral region outside the swamp forest. Of these, Lepironia articulata is particularly dominant, and Pandanus helicopus and to a lesser extent Eleocharis ochrostachys are dominant. Forests occur on islands of deep peat and are usually low, barely exceeding 28m in height. The trees have many epiphytic bryophytes, ferns and orchids. In the understorey are ferns, screw pines, sedges and mosses (Gleichenia spp, Pandanus spp, Thoracostachyum banacanum and Sphagnum spp). In the drier forests that adjoin the wetland, palms Licuala sp, Penanga sp; dipterocarps Dipterocarpus spp, Shorea spp; and buttressed species of Dillenia and Koompassia are characteristic. There are also extensive areas covered by Lalang Imperata cylindrica grasslands.
Land tenure:
State owned (Pahang State Government).
Conservation measures taken:
The wetland is situated within the Tasek Bera Forest Reserve (40,038 ha).
Conservation measures proposed:
The area has been proposed as a Nature Reserve Park (Government of Malaysia, State of Pahang 1972). Other proposals include: (a) further study of the community metabolism, for application to other areas; (b) study of the factors governing speciation, in view of Tasek Bera's unusually rich flora and fauna; and (c) protection of an area of at least 20,000 ha for biological purposes, to include the swamp and adjacent terrestrial systems with a zone of at least l,000m around the swamp (Furtado & Mon 1982).
Land use:
Aboriginal use (fisheries and shifting cultivation), tourism and trade in aquarium fishes. The Department of Drainage and Irrigation has one irrigation project of 23 ha. There are oil palm plantations and logging operations in surrounding areas.
Possible Changes in Land use:
The Bukit Ibam forest (48,600 ha) will probably become a TFL area (sustained yield forest).
Disturbances and threats:
These include: (1) shifting cultivation by Selamai natives; (2) possible pollution from the Sungei Bera-Sungei Pahang and Sungei Palong-Sungei Muar river systems through reverse flow during flood conditions during the northeast monsoon; (3) forest destruction in the watershed leading to an increase in erosional load; (4) mining activities (iron extraction) causing siltation; (5) disturbance from a network of logging roads surrounding the Tasek and from several trails reaching to or near the shoreline in the south and west (6) alteration in the local drainage patterns and increased siltation in tributaries to the west, caused by logging operations, especially road construction.
Economic and social values:
Water purification, scientific research, conservation education, rice cultivation, tourism and fisheries. The fishes of the Tasek Bera region are of great importance in three ways: (1) as a source of protein for the local population (30 marketable species of fish occur); (2) for sport fishing (at least 15 potential sport fishes occur); and (3) for trade in aquarium fishes (approximately 50 species of aquarium fishes occur including at least 20 of special interest). The annual export value of aquarium fishes in the whole of Pahang Tenggara is reported to be M$2 million to which Tasek Bera contributes a considerable amount. Much of the area consists of productive forest, and considerable areas around the lake have the potential to become productive forest. In the northern part of the area, the drainage is generally very poor which makes it unsuitable for many crops. In the southern part, erosion hazards exist because of slopes of 6-12 degrees (EPU, 1980).
Tasek Bera is one of the two major natural bodies of freshwater on the Malay Peninsula and supports a biological community which is unique within Malaysia and possibly represented nowhere else in the world. It has a high ecological diversity and supports a large number of plant and animal species, some of which are endangered and/or endemic. Thus the area is of great importance as a gene pool besides being of interest from a scientific, recreational, educational and economic point of view.
Fauna:
Some 95 species of fishes have been recorded from 22 families, notably Cyprinidae, Anabantidae and Luciocephalidae. Almost all species seem to be indigenous to Peninsular Malaysia. Cat-fishes (Siluriformes) accounted for 19 species. Species of note are the endangered Schierophages formosus and Probarbus jullieni. About 200 species of birds are known to occur, including six species of herons and egrets (Ardeidae), eight species of shorebirds (Charadriiformes) and one duck (Anatidae). The mammals include Bos gaurus, Elephas maximus, Tapirus indicus, Panthera tigris, Sus scrofa and Cervus unicolor. Virtually all of the amphibians and reptiles of Malaysian tropical swamps are present including the endangered False Gharial Tomistoma schlegelii.
The zooplankton is poor because of the low pH, and only 64 taxa have been recorded. Macrochaetus collinsii (Rotifera) is a rare species particularly worthy of note. Aquatic insects and benthic animals belong to Diptera, Trichoptera, Ephemoptera, Lepidoptera, Odonata, Hemiptera, Heteroptera, Coleoptera, Annehida and Decapoda. Two species of shrimps, Macrobrachium trompi and Caridina thambipillai, and one species of freshwater crab, Potamon johorense, have been recorded.
Special floral values:
The wetland possesses rich algal, aquatic macrophyte and swamp forest communities, and has several endemic plant species such as Pandanus spp, Cryptocoryne cordata and Gnetum gnemonoides. Scirpus con fervoides is of distributional interest.
Research and facilities:
A four-year research project within the International Biological Programme was undertaken jointly by the University of Malaya and the Japanese Government in order to study the primary productivity of tropical freshwater streams and swamps and the related ecosystem. Furtado and Mon (1982) and Government of Malaysia, State of Pahang (1972) have described the fishes, birds, aquatic insects and benthic animals of the swamp in some detail.
References:
DID Pahang (undated); EPU (1980); Furtado & Mon (1982); Government of Malaysia, State of Pahang (1972); IUCN (in prep); Wong (1974).
Criteria for Inclusion:
1b. 1e, 2a, 2b, 2d.
Source:
Richard P. Lim, Ahmad Fuad Embi, Chop Ai Kuang and George A.C. Tee.