Horton Plains National Park

Horton Plains National Park
IUCN category II (national park)
World's End, a sheer precipice within the park
Location	Central province, Sri Lanka
Nearest city	Nuwara Eliya
Area	3,160 hectares (12.2 sq mi)
Established	1969
Governing body	Department of Wildlife Conservation
World Heritage site	in tentative list 2006

Horton Plains National Park (Sinhala: හෝටන් තැන්න), is a cloud forest in the central highlands of Sri Lanka. It is rich in biodiversity with high endemicity, and is a popular tourist destination. Horton Plains was designated as a wildlife sanctuary on 5 December 1969, and because of its biodiversity, it was elevated to a National Park on 18 March 1988. The area was named after Sir Robert Wilmot-Horton, the British governor of Ceylon from 1831-1837. The 3,160 hectares (12.2 sq mi) park is contiguous with the Peak Wilderness Sanctuary in the west. Horton Plains supports the most extensive area of cloud forest still existing in Sri Lanka. Horton Plains National Park along with Peak Wilderness Sanctuary and Knuckles Mountain Range is currently on a tentative list of potential World Heritage Sites. They are listed under mixed criteria of selection. The park is situated 32 kilometres (20 mi) from Nuwara Eliya.

Horton plains lies at an altitude of about 2,100–2,300 metres (6,900–7,500 ft), and is an important water source, acting as the headwater for three important Sri Lankan rivers, the Mahaweli, Kelani, and Walawe. Stone tools dating back to Balangoda culture have been found here. The plains' vegetation is grasslands interspersed with montane forest, and includes many endemic woody plants. Large herds of Sri Lankan Sambar Deer feature as typical mammals, and the park is also an Important Bird Area in Sri Lanka with many endemic species, some of which are strictly endemic to the plains. Forest dieback is one of the major threats to the park; a recent study concluded that the dieback is caused by a natural phenomenon. The sheer precipice of World's End, and Baker's Falls are among the visitor attractions of the park.

Physical features

Horton Plains is located on the southern plateau of the central highlands of Sri lanka. The peaks of Kirigalpotta 2,389 metres (7,838 ft) and Thotapolakanda 2,357 metres (7,733 ft), the second and the third highest mountain peaks of Sri Lanka, are situated to the west and to the north respectively. The park's elevation ranges from 2,100–2,300 metres (6,900–7,500 ft). The rocks found in the park belong to a Precambrian era highland series and include Khondalites and Charnokites. They consist mostly of granites. The soil type is of the red-yellow podsolic group and the surface layer is covered with decayed organic matter.

The mean annual rainfall is greater than 2,000 millimetres (79 in) with high humidity. Frequent cloudy skies limit the amount of sunlight that can fall on plants. Temperature varies considerably through the course of one day, reaching as high as 27 °C (81 °F) during the day time, and dipping as low as 5 °C (41 °F) in the nights. During the southwest monsoon season, the wind speed sometimes reaches gale force strength. Although some rain falls throughout most the year, a dry season occurs from January-March. Mean annual temperature is around 13 °C (55 °F) and ground frost is common in February. Mist can persist throughout rainy days. Many water pools and waterfalls can be seen in the park, and Horton Plains is considered the most important watershed in Sri Lanka. Due to its high elevation, fog and cloud deposit a considerable amount of moisture on the land. However this moisture escapes back into the atmosphere as evaporation from the tree canopy. In Sinhala the plains are known as Mahaweli Plains. Agra Oya, a tributary of Kotmale Oya, which in turn a tributary of the Mahaweli River, has its source in the park.

Human history

The park is named after Sir Robert Wilmot-Horton, the British governor of Ceylon, who travelled to the area to meet the Ratemahatmaya of Sabaragamuwa in 1836. Under the British rule the area received some protection, which prohibited the felling of montane forests above 5,000 feet (1,500 m). Horton Plains was originally designated as a wildlife sanctuary on 5 December 1969, and was elevated to a National Park on 18 March 1988. Stone tools dating back to Balangoda culture have been found here. The local population who resided in the lowlands ascended the mountains to mine gems, extract iron ore, construct irrigational canal and fell trees for timber. A 6 metres (20 ft) long core of material retrieved from a mire revealed that in the late quaternary period the park area had a semi-arid climate and a species-restricted plant community.

Flora

Rhododendron arboreum dominates flora of the park

The vegetation of the park is classified into two distinctive groups, 2,000 hectares (7.7 sq mi) of wet patana (Sinhalese for "montane grasslands") and 1,160 hectares (4.5 sq mi) of subtropical montane evergreen forests. A total 744 plant species belonging to 20 families have been recorded from the park. The forest canopy reaches the height of 20 metres (66 ft) and features Calophyllum walkeri, forming communities with varieties of Myrtaceae species such as Syzygium rotundifolium, and S. sclerophyllum, and Lauraceae members including Litsea, Cinnamomum, and Actinodaphne speciosa. The undergrowth layer is characterised by Strobilanthes spp. The thickness of the Strobilanthes vegetation hinders the development of a herb layer. Dwarf bamboo species such Indocalamus and Ochlandra also found in the undergrowth layer. Rhodomyrtus tomentosa bushes specially grow in forest margin and near the mountain peaks. Species such as Gordonia, and Rhododendron arboreum have spread to Sri Lanka, via mountains of South India from the Himalayas and are now common. 54 woody plant species have been recorded from the park, of which 27 (50%) are endemic to Sri Lanka.

Adam's Peak seen across the grasslands of the park

Frequent fire and grazing characterises Plagioclimax communities of the grassland flora. Grasslands are dominated by Arundinella villosa and Chrysopogon zeylanicus. Waterlogged swamps or slow moving streams are found in low lying areas, and macrophytes such as Aponogeton jacobsenii, sedge species Isolopis fluitans and Utricularia spp. are found near the slow moving streams. The bamboo Chimonobambusa densifolia thrive along the banks of the streams, and near the swampy areas grass species such as Juncus prismatocarpus, Garnotia mutica, Eriocaulon spp. and Exacum trinervium are common. Tussock grasses such as Chrysopogon zeylanicus and Cymbopogon confertiflorus are found in the wet hollows. Herbaceous flora of the grasslands include temperate species including Ranunculus, Pedicularis, Senecio, Gentiana and Alchemilla and also tropical species such as Eriocaulon and Ipsea speciosa (a rare endemic daffodil orchid).

Hanging lichens such as Usnea barbata are also common. A number of ferns and orchids can be seen in the park. 16 of the orchid species being endemic. Other notable plants include shrubs such as the endemic, Rhodomyrtus tomentosa, Gaultheria fragrantissima, herbs, Exacum trinervium, E. walkeri, Drosera indica, and tree ferns Cyathea spp. Anzia, a foliose lichen genus belonging to Parmeliaceae family, which had not been recorded in Sri Lanka previously, was discovered in Horton Plains in a study carried out in 2007. There were conflicting views on how the grasslands of the park came into being, but now it is accepted that the grasslands in dry slopes were created by forest clearance and maintained by burning and grazing. Grasslands in low lying areas were naturally created where conditions were too wet and perhaps frost and soil erosion could be contributing factors.

Fauna

Faunal species recorded from the park include 24 species of mammals, 87 species of birds, 9 species of reptiles and 8 species of amphibians.

Mammals

Sri Lankan Sambar Deer occur in large herds

The Sri Lankan Elephant disappeared from the region in the 1940s at the latest. A large herd of about 1500 individuals of Sri Lankan Sambar Deer roam the park. Other mammals living in the park include Kelaart's Long-clawed Shrews, Red Slender Loris, two endemic Old World monkeys, Toque Macaques, Purple-faced Langurs, Rusty-spotted Cat, Sri Lankan Leopards, Wild boars, Stripe-necked Mongooses, Sri Lankan Spotted Chevrotains, Indian Muntjacs, and Grizzled Giant Squirrels. Fishing Cats and European Otters visit the wetlands of the park to prey on aquatic animals. A subspecies of Red Slender Loris, the Horton Plains Slender Loris Loris tardigradus nycticeboides is found only in highlands of Sri Lanka. This species appeared on the list of the World’s 25 Most Endangered Primates in 2004. W. W. A. Phillips in 1980 says that the loris that "would appear to be the rarest of all mammals in Sri Lanka." The loris could possibly be a distinct species and its habitat is restricted to a small area of 400 square kilometres (150 sq mi).

Birds

Along with Ohiya, Pattipola and Ambewela, Horton Plains forms one of the Important Bord Areas (IBAs) in Sri Lanka. Together with the adjacent Peak Wilderness Sanctuary, Horton Plains contains 21 bird species which occur only on Sri Lanka. Four, Sri Lanka Blue Magpie, Dull-blue Flycatcher, Sri Lanka White-eye, and Sri Lanka Wood-pigeon, occur only in Horton plains, while other endemic species include Sri Lanka Spurfowl, Sri Lanka Junglefowl, Yellow-fronted Barbet, Orange-billed Babbler, Sri Lanka Bush-warbler, and Sri Lanka Whistling-thrush. Many birds migrate here in winter including Swiftlets, and Alpine Swift. Crested Serpent-eagle, Mountain Hawk-eagle, Black-winged Kite, and Peregrine Falcon are the birds of prey found in Horton Plains. Harriers are among the migratory raptors. This is a key wildlife area. All six highland endemic birds are found here, including Dull-blue Flycatcher, Sri Lanka White-eye, Sri Lanka Wood Pigeon, and Sri Lanka Bush Warbler. Yellow-eared Bulbul and Black-throated Munia are widespread throughout the highlands.

Reptiles and amphibians

Many amphibians inhabit the watercourses of the park including endemic species such as Polypedates eques, P. longinasus, Fejervarya greenii, Lankanectes corrugatus, and Microhyla zeylanica. Philautus microtympanum, Ramanella palmata, P. femoralis and Theloderma schmardanum are also endemic frogs. Some of the frog species Horton plains are now extinct. They are Philautus leucorhinus, P. temporalis, and P. variabilis. Calotes nigrilabris, Lankascincus taprobanensis, Rhino Horn Lizard and Cophotis ceylanica are the skinks and lizards. Aspidura trachyprocta and Rat snake are snakes of the park.

Fish and crustaceans

Two fish species found in the park, common carp and rainbow trout, both are introduced species. Horton Plains is also home to many endemic crustaceans including Caridina singhalensis and Perbrinckia spp..

Conservation

Horton Plains was a part of a large system of plains and forest cover in Agra-Bopats, Moon Plains and Elk Plains. Between 1831 and 1948, Horton Plains became a Sambar deer hunting ground. Elephants and Wild Boar were also hunted to lesser extent. During this period lower slopes were cleared initially for coffee and then for tea plantations. As a result Horton Plains and Peak Wilderness became isolated from other forest and grassland areas. Potato was cultivated in grassland but closed down in 1977. After the National Park was proclaimed, these areas were reinstated as grasslands. Tourism-related issues such as plant removal, litter, fires and noise pollution are major issues of conservation. Gem mining, timber logging, the collection of plants for ornamental and medicinal purposes, encroachment, poaching and vehicle traffic are other considerable threats. The spread of invasive alien species such as Ulex europeus spp., Brackens, and Pennisetum spp. are threatening existing plants. Rainbow trout may have affected the endemic species such as amphibians and crustaceans. Some Sambar Deer have died due to eating polythene litter that blocked their food passages, and visitors are entering are banned from bringing polythene into the park.

A recent threat is forest dieback in peripheral areas, first reported in 1978. In some areas this has become a severe problem with 50% of reduction of the plants of those areas. Water deficiency is attributed as the main cause of dieback as droughts are becoming more frequent. Regrowth of forest is hindered by frost which is becoming more severe. The forest dieback has affected 22 plants with Calophyllum walkeri being the most effected. A study has shown the soil toxicity or metallic elements in decaying tree leaves are not the cause of dieback. It concluded that dieback is a natural phenomenon caused by imbalance of levels of macronutrients and micronutrients resulting from weathering and leaching.

Visitor attractions

See also: Baker's Falls

World's End is a major attraction

Horton Plains is a popular tourist destination, with World's End being the main attraction. In the six months ending in August 2009, Horton Plains National Park earned a revenue of Rs. 20.1 millions. World's End is a sheer precipice with a 4,000 ft (1,219 m) drop. It is situated at the southern boundary of the park. Another cliff known as the Lesser World's End is also located a little distance away from the World's End. Baker's Falls is a waterfall formed by Belihul Oya, a tributary of Walawe River. The falls are named after Sir Samuel Baker, a famous explorer who attempted to establish a European agricultural settlement in Nuwara Eliya. The falls are 20 metres (66 ft) high. Slab Rock Falls lies 1 kilometre (0.62 mi) to north of Baker's Falls.

See also

• Protected areas of Sri Lanka

External links

Media related to Horton Plains National Park at Wikimedia Commons