| Phi Pan Nam Range | |
|---|---|
| ทิวเขาผีปันน้ำ | |
 The Phi Pan Nam Range and theYom River inLong District, Phrae Province | |
| Highest point | |
| Peak | Doi Luang |
| Elevation | 1,694 m (5,558 ft) |
| Coordinates | 19°8′04″N99°45′29″E / 19.13444°N 99.75806°E /19.13444; 99.75806 |
| Dimensions | |
| Length | 400 km (250 mi) NE/SW |
| Width | 135 km (84 mi) SE/NW |
| Geography | |
 | |
| Countries | Thailand andLaos |
| Range coordinates | 18°48′0″N99°50′30″E / 18.80000°N 99.84167°E /18.80000; 99.84167 |
| Parent range | Thai highlands |
| Geology | |
| Rock age | Triassic |
| Rock type(s) | Sandstone andlaterite |
ThePhi Pan Nam Range, alsoPee Pan Nam,[1] (Thai:ทิวเขาผีปันน้ำ,pronounced[tʰīwkʰǎwpʰǐːpānnáːm]) is a 400 km (249 mi) long system of mountain ranges in the eastern half of theThai highlands. The range lies mostly inThailand, although a small section in the northeast is withinSainyabuli andBokeo provinces ofLaos.
In Thailand the range extends mainly acrossChiang Rai,Phayao,Lampang,Phrae,Nan,Uttaradit andSukhothai Provinces, reachingTak Province at its southwestern end. Thepopulation density of the area is relatively low. Only two sizable towns,Phayao andPhrae, are within the area of the mountain system and both have fewer than 20,000 inhabitants each. Larger towns, likeChiang Rai andUttaradit, are near the limits of the Phi Pan Nam Range, in the north and in the south, respectively.
Phahonyothin Road, part of theAH2 Highway system, crosses the Phi Pan Nam Range area from north to south, between Tak and Chiang Rai. There are tworailway tunnels of theNorthern Line across the Phi Pan Nam mountains. Both are on the south side of the range: the 130.2 m Huai Mae Lan Tunnel in Phrae Province and the 362.4 m Khao Phlueng Tunnel in Uttaradit and Phrae Provinces.[2]
In the mountains north ofThoeng, at the northeast end of the range,Hmong people live in small villages such as Ban Saen Than Sai and Ban Phaya Phripak, the latter on top of a mountain pass.
The Phi Pan Nam Range is composed of many smaller mountain chains roughly aligned in a north–south direction in its northern part and, further south, in a northeast–southwest direction. These ranges cover an extensive area and are often separated byintermontane basins or lowlands. They end in the west with theKhun Tan Range, in the east with theLuang Prabang Range, and with theCentral Plain of Siam in the south. The northern tip is bound by theMekong River.[3]
There arecolumnar basalt formations in Mon Hin Kong (Thai:ม่อนหินกอง) in an area in the mountains near Na Phun,Wang Chin District, Phrae Province.[4] InPhae Mueang Phi there aremushroom rocks and other bizarre rock formations caused byerosion.[5]
The Phi Pan Nam range system is often divided into twophysiographic longitudinal sections:
The highest point is the 1,694 metres (5,558 ft) high summit known asDoi Luang.[9][10] It is in the northwestern area of the range near Phayao town, but there are a number of lesser mountains with the name 'Doi Luang' throughout the range. Other noteworthy peaks are:
The Phi Pan Nam range of mountains is not as high as neighboring mountain systems. It is, however, significant from thehydrographic point of view. These mountains divide theMekong from theChao Phrayawatershed and important rivers of Thailand have their source in the Phi Pan Nam area. Its name in Thai "ทิวเขาผีปันน้ำ" roughly means "the mountains of the spirits dividing the waters", 'spirits' (ผีphi) here referring to ancient mountaindeities ofThai folklore.
Among the Thai rivers that originate in the Phi Pan Nam Mountains the main ones are theWang andYom River, with their tributaries such as theNgao, flowing towards the Chao Phraya. TheIng and theLao, a tributary of theKok River, flow northwards and are part of the Mekong basin. A great number of smaller rivers have their sources in mountains across the range.
TheSirikit Dam is at the southeastern edge of the Phi Pan Nam mountains.
There were formerly largeteak forests in some areas of the range. However, at the beginning of the 20th century concessions were given tologging companies and the forest cover dwindled dramatically especially in lowland areas between ranges.[26]Deforestation also has affected areas that were cleared for local agriculture. Oftenwildfires are deliberately set off by local farmers, as well as by speculators who hire people to set forests on fire in order to claim land title deeds for the areas that have become "degraded forest".[27]
Owing to the relative isolation of the area there wasCommunist insurgency in the mountainous forests of the Phi Pan Nam Range during theCold War. A memorial was erected on 1,118 m highDoi Phaya Phipak (ดอยพญาพิภักดิ์) to commemorate the victims of the battles between troops of theRoyal Thai Armed Forces and the insurgents of theCommunist Party of Thailand between the 1950s and the 1970s.[28] There is now a historical site and a forest park at Doi Phaya Phipak, also known as Phaya Phipak.[29]
A controversialdam was planned in the central area of the range on theYom River inKaeng Suea Ten in 1991 but this project was later abandoned in the face of popular opposition.[30][31] The debate about the dam, however, resumed in 2011.[32] Two smaller dams on the Yom River may be built instead of the Kaeng Suea Ten mega-dam.[33]
Generally the forested areas of the Phi Pan Nam are known for theirteak and bamboo forest. The mountain ranges are covered withtropical dry broadleaf forests, including sections ofmoist evergreen forest,mixed deciduous forest,dry deciduous forest, as well ashill evergreen forest at higher altitudes. There is greatbiodiversity in these mountains and their fewunspoilt valleys, with a wide range of animal and plant species.[34] The whole area of the range is part of theCentral Indochina dry forestsecoregion.[35][36]
There are a number ofprotected areas in the Phi Pan Nam mountains, mostly encompassing mountainous terrain. These are patchily distributed across the range, and the largest national parks are in its central part, roughly aroundPhayao town. Protected sectors are typically surrounded by agricultural zones, often near roads and villages and thus with vast surfaces under the influence of theedge effect.[37]
Besides thenational parks and wildlife reserves, there are theHuai TakTeakBiosphere Reserve in Lampang Province[38] and thePhu Langka Forest Park,[39] located inChiang Kham District andPong District of Phrae Province. The main attractions of the forest park areDoi Hua Ling,Doi Phu Lang Ka andDoi Phu Nom;[40] the latter is abreast-shaped hill rising in an area ofgrassland.[41]
Formerly there were large extensions of teak (Tectona grandis) forests in the range, including the highly appreciated golden teak variety. These forests are now much reduced. Forest fires are common during the dry season.
Some of the other species of trees found in the forests of the mountains are:Afzelia xylocarpa,Ailanthus triphysa,Anisoptera costata,Artocarpus lacucha,Berrya ammonilla,Betula alnoides,Cinnamomum iners,Dalbergia oliveri,Dillenia pentagyna,Dipterocarpus obtusifolius,Dipterocarpus alatus,Dipterocarpus turbinatus,Duabanga grandiflora,Garcinia indica,Hopea odorata,Irvingia malayana,Lagerstroemia loudonii,Lagerstroemia calyculata,Lagerstroemia tomentosa,Lithocarpus densiflorus,Mangifera caloneura,Michelia champaca,Michelia floribunda,Pterocarpus macrocarpus,Schleichera oleosa,Terminalia bellirica,Toona ciliata,Vitex pinnata andXylia xylocarpa.
Theendangered animal species sheltered by some of the fragmented, although relatively undisturbed Phi Pan Nam forests are thefishing cat,sun bear,Asiatic black bear,Chinese pangolin,Indochinese tiger,sambar deer,gaur,Bengal slow loris,Sunda pangolin, as well as theAsiatic softshell turtle and thebig-headed turtle.
There are alsoAsian elephants in their natural habitat in a few protected areas, such as in theSi Satchanalai National Park. Formerly there were also in theWiang Ko Sai National Park but there have been no sightings in recent years.[42]Thegreen peafowl, now rare in the wilderness and threatened byhabitat destruction throughoutSoutheast Asia, breeds in the central mountains of the range from January to March.
Among the other animals, theIndian muntjac,Burmese hare,Indian hare,Indochinese flying squirrel,black giant squirrel,Java mouse-deer,jungle cat,mainland serow,masked palm civet,Asian palm civet,Malayan civet,bamboo rat andnorthern treeshrew, as well as theBengal monitor deserve mention.[43]
A variety of birds are found in the range such as theblue-winged siva,white-rumped shama,scaly-breasted munia,black bulbul,blue-throated barbet,pin-striped tit-babbler,blue-bearded bee-eater,crested kingfisher,sooty-headed bulbul,coppersmith barbet,great hornbill,chestnut-headed bee-eater and thered-billed blue magpie.[44]
![The endangered green peafowl. Its preferred habitat is dry deciduous forest close to water and away from human disturbance.[45]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aPavo_muticus_-_Hai_Hong_Karni.jpg)
