Flora and fauna

The mountains and the southwestern part of the country, known as the "wet zone", receive ample rainfall at an average of 2,500 mm (98 in). Most of the east, southeast, and northern parts of the country comprise the "dry zone", which receives between 1,200 mm (47 in) and 1,900 mm (75 in) of rain annually. Much of the rain in these areas falls from October to January; during the rest of the year there is very little precipitation. The arid northwest and southeast coasts receive the least amount of rain at 600 mm (24 in) to 1,200 mm (47 in) per year.

Varieties of flowering acacias are well adapted to the arid conditions and flourish on the Jaffna Peninsula. Among the trees of the dry-land forests, are some valuable species such as satinwood, ebony, ironwood, mahogany and teak. In the wet zone, the dominant vegetation of the lowlands is a tropical evergreen forest, with tall trees, broad foliage, and a dense undergrowth of vines and creepers. Subtropical evergreen forests resembling those of temperate climates flourish in the higher altitudes. Forests at one time covered nearly the entire island, but by the late 20th century lands classified as forests and forest reserves covered around ⅓ of the land.^[22]

The Yala National Park in the southeast protects herds of elephant, deer, and peacocks, and the Wilpattu National Park in the northwest preserves the habitats of many water birds, such as storks, pelicans, ibis, and spoonbills. During the Mahaweli Ganga Program of the 1970s and 1980s in northern Sri Lanka, the government set aside four areas of land totalling 1,900 km² (730 sq mi) as national parks. The island has four biosphere reserves, Bundala, Hurulu Forest Reserve, the Kanneliya-Dediyagala-Nakiyadeniya, and Sinharaja.^[23]

The national flower of Sri Lanka is the Nymphaea stellata (Sinhalese Nil Mahanel),^[24] the national tree is the Ironwood (Sinhalese Na),^[25] and the national bird is the Sri Lanka Junglefowl, which is endemic to the country.^[26]