Pa Phru
Location:
 6°03'-6°21'N, 101°50'-102°03'E; in the Sungei Golok basin, between Tak Bai, Sungai Golok and Sungai Padi Districts, Narathiwat Province, within a few km of the Malaysian border.
Area:
 34,636 ha.
Altitude:
 Near sea level.
Biogeographical Province:
 4.7.1.
Wetland type:
 21 & 22.
Description of site:
 A large depression, approximately 28 km by 8 km and within seven km of the coast, supporting 9,684 ha of primary peat swamp forest in proximity to 14,600 ha of Melaleuca woodland and scrub, and 9,800 ha of degraded grasslands. The site is separated from the sea by a belt of low-lying country to the east. To the west, the site is bounded by further lowland cultivation and a mountainous ridge which rises to 1,1 82m. The human population density is high and the higher ground around the margins of the site bears a network of roads. A smaller area of degraded peat swamp, from which all the primary forest has been removed, lies to the north, on the opposite bank of the Bang Nara River. The northern part of the site drains into the Bang Nara River while the southern parts empty into the Sungei Golok River system. The site is a permanent swamp with an average water depth of l.0-1.5m (maximum 2.0m), although there may be fluctuations in water level of up to one metre. The water overlies 5-8m of peat. Extensive flooding may occur in surrounding areas during the northeast monsoon season. The pH is approximately 7.0 in the primary peat swamp forest and as low as 4.0-5.0 in the degraded areas. The Bang Nara River is tidal.
Climatic conditions:
 Humid tropical climate. This is one of the least seasonal regions of the country, with an average annual rainfall of 2,643.4 mm falling throughout the entire year. The wettest months are October to December, during the northeast monsoon, when the monthly precipitation is usually 300 to over 500 mm. During the driest months, February to April, the average monthly rainfall is 60-80 mm. The relative humidity is always high, ranging from 77.0% to 85.0%. The average daily temperature is rather constant at 26.2-28.6°C.
Principal vegetation:
 In the open water swamp, floating aquatic plants include Eichhornia crassipes, Spirodela polyrhiza and Jussiaea repens. Submerged aquatics include Blyxa japonica, B. echinosperma, Najas graminea and Hydrilla verticillata. Emergents include Eleocharis dulcis, Fimbristylis miliacea, F. acuminata, Monochoria vaginalis, Nymphaea nouchali and Lindernia crustacea. The dominant plants in marginal areas of the swamp include Ceratopteris thalictroides, Leersia hexandra, Jussiaea linifolia, Blechnum orientale, Lygodium microphyllum, Stenochlana palustris and Acrostichum aureum.

A species-rich primary peat swamp forest is found in the least disturbed areas. The upper storey includes Neesia altissima, Dacryodes incurvata, Podocarpus wallichianus, Elaeocarpus grandiflorus, Stemonurus malaccensis, Cratoxylum arborescens, Xylopia fusca, X. maingayi, Palaquium obovatum and a great variety of other species. The middle storey includes Myristica elliptica, Goniothalamus giganteus, Polyalthia curtisii, Crudia caudata, Baccaurea bracteata, Blumeodendron kurzii and Cinnamomum sp among other species. The lower storey includes Eleiodoxa conferta, Calamus caesius, Pandanus spp and Mapania sp. Koompassia malaccensis occurs around the margins of the site. In those parts of the area which have been cut, the succession is initiated by such species as Macaranga prunosa, Aistonia spathulata, A. pneumatophora and Archidendron clypearia. As a result of repeated disturbance, especially through the agency of fire, large areas have come to be dominated by Melaleuca cajeputi from which any succession back to peat swamp forest is impossible (Santisuk & Niyomdham, 1985). Surrounding areas are mainly cultivation and degraded scrubland.
Land tenure:
 The wetland is state owned; surrounding areas are privately owned small-holdings.
Conservation measures taken:

Part of the site (16,000 ha) was declared as a Non-Hunting Area in 1985. Most remaining forest, almost all of which lies within the boundaries of the Non-Hunting Area, is classified as National Reserve Forest. A management strategy for the entire area is to be developed by the Pikultong Development Research Center during 1987-89. The terms of reference of the project are as follows:

  1. to evaluate the existing conditions of the resources at Phru To Daeng (also known as Pa Phru);
  2. to minimize or mitigate the environmental impacts from development plans which have already been implemented;
  3. to establish guidelines for the sustainable development and conservation of the peat swamp;
  4. to integrate the policy and coordinate the work of the various government agencies involved in the development of wetlands;
  5. to compile a development strategy which will take account of environmental and natural resources aspects as well as socio-economic aspects.

The site has already been zoned for land use according to the following categories (Anon, 1985c):

  1. A reserve zone, encompassing all the primary peat swamp forest (9,180 ha).
  2. A conservation zone, for rehabilitation of disturbed forest (17,589 ha).
  3. A development zone in areas where the forest has been totally destroyed. This will be available for appropriate agricultural development, irrigation, road construction etc. (15,127 ha).
Conservation measures proposed:
 The Wildlife Conservation Division is attempting to establish the major part of the site as a Wildlife Sanctuary, which would enable it to receive full habitat protection in law. The site has also been proposed as a Biosphere Reserve. The use of fires should be strictly controlled. There should be a moratorium on all further development at the site until the likely impact of any further changes in land use have been evaluated under the above studies.
Land use:
 Fishing and the collection of forest products such as the fruits of Eleiodoxa conferta, an understorey palm; cultivation of rubber, rice and vegetables and production of charcoal in surrounding areas.
Possible changes in land use:
 The Irrigation Department has already initiated some drainage operations in order to minimize flooding around the site. A canal, draining into the Bang Nara River, has been dug into parts of the area although its continuation into the remaining swamp forest has so far been prevented. Some 4,200 ha of the degraded area have been gazetted for settlement under the Cooperative Promotion Department of the Ministry of Agriculture, in order to establish villages where the main activities would centre around rice and rubber cultivation.
Disturbances and threats: As above; developments undertaken since 1981 by the Royal Irrigation Department and the Cooperatives Promotion Department have severely damaged the integrity of the site, reducing the area of primary peat swamp forest by two-thirds. However, the widespread realization that these developments have damaged the scientific and conservation value of the site and actually reduced, rather than increased, the benefits reaped by local people has led to their cessation. The areas of acidic, peaty soils exposed by cutting and through the use of fire can only sustain rice cultivation for one or two years before they lose their fertility and are colonized by Melaleuca scrub. As the total area of the site is reduced through drainage, so the possibility of accidental fire damage to remaining primary forest is increased. Large areas were damaged by a major peat fire in the dry season of 1983.
Economic and social values: The local people derive considerable benefits from the forest products which they harvest from the site. These include forest fruits, rattans and hardwoods as well as fish and frogs. The raw fruits of the palm Eleiodoxa conferta could be sold for Bht.80 (about US$3.00) per 20 litres in 1983. The leaves of the palm Metroxylon sagus are used for making thatch while the stems are utilized as fodder for pigs and chickens, as a table vegetable, and for extracting starch used in making tiour. The fruits are eaten by children.

The site is unique in Thailand and has very great research and educational potential. The local inhabitants belong to an ethnic minority with Malaysian affinities. Their lifestyle differs greatly from that of the Central Thais and is in danger of being disrupted through the introduction of inappropriate or unsustainable agricultural techniques.
Fauna: The area supports the walking catfish Prophagorus nieuhofi which, according to Bain and Humphrey (1982), is threatened in Thailand. Other species of fish known to occur include Notopterus notopterus, Cyclocheilichthys repasson, C. apogon, Hampala macrolepidota, Puntius fasciatus, P. leicanthus, Clarias macrocephalus, Anabas testudineus, Trichogaster pectoralis, T. trichopterus, Channa lucius, C. micropeltes, C. strialus and Mastacembelus armatus. The site may conceivably still support Scleropages formosus, which is endangered throughout its Southeast Asian range.

As regards its avifauna, the site is chiefly of note for the variety of terrestrial lowland forest birds which it supports. Most such species are endangered in Thailand as a result of the almost complete destruction of the lowland rainforest biome. They include Treron capellei, T. fulvicollis, Otus rufescens, Harpactes kasumba, Anthracoceros malayanus, Megalaima rafflesii, Malacopteron affine, Macronous ptilosus and Stachyris nigricollis. This is also the only known site in Thailand for Copsychus pyrropygus. Prionochilus thoracicus is present and Rhyticeros corrugatus could occur. The Grey-headed Fish-Eagle Ichthyophaga ichthyaetus, an endangered species in Thailand and Malaysia, is still present. Three Lesser Adjutant Storks Leptoptilos javanicus were seen in the area in late September 1987.

Mammals include the Banded Leaf Monkey, Long-tailed Macaque, Flat-headed Cat, Tiger and Lesser Mouse Deer (Presbytis melalophos, Macaca fascicularis, Felis planiceps, Panthera tigris and Tragulus javanicus). The Agile Gibbon Hylobates agilis was formerly present but has now been extirpated. Important and endangered reptiles known from the area include the False Gharial Tomistoma schlegelii and the Bornean Painted Callagur Callagur borneoensis. Among economically important invertebrates, both Macrobrachium lanchesteri and M. rosenbergii are present.
Special floral values: The site is unique; over fifty species of plants new to Thailand have been discovered here. In addition, there are no fewer than 66 tree species in 29 families which are judged to be of economic importance (Dr Chawalit Niyomdham, pers. comm). This is the only site in Thailand for the palm Cyristachys laka.
Research and facilities: Detailed research on the botany of the site is being carried out at the request of the government by Dr Thawatchai Santisuk and Dr Chawalit Niyomdham of the Silviculture Division in the Royal Forest Department. A detailed inventory of the vertebrate fauna has been made by the Technical Section of the Wildlife Conservation Division, Royal Forest Department. A management plan (Anon, l985c) has already been produced and further evaluation of the site will be carried out during 1987-89 by the Pikulthong Development Research Center. Accommodation is available at the headquarters of the Non-Hunting Area.
References: Anon (1985c); Bain & Humphrey (1982); Chookajorn et al. (1985); Naksiri (1985); Round (1988); Santisuk & Niyomdham (1985).
Criteria for inclusion: 1b, 2a, 2b.
Source:
 Jira Jintanugool and Philip D. Round.