Lying within the Indomalaya ecozone, Sri Lanka is one of the 25 biodiversity hotspots
in the world. Although the country is relatively small in size, it has the highest
biodiversity per 10,000 square km in Asia. Remarkably high proportion of the species
among its flora and fauna, 27% of the 3,210 flowering plants and 22% of the mammals,
are endemic. Sri Lanka has declared 24 wildlife reserves, which are home to a wide
range of native species such as Asian elephants, leopards, sloth bears, the unique
small loris, a variety of deer, the purple-faced langur, the endangered wild boar,
porcupines and anteaters.

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.

The Yala National Park in the southeast protects herds of elephant, deer, and peacocks,
and the Wilpattu National Park, the largest national park in Sri Lanka, in the northwest
preserves the habitats of many water birds, such as storks, pelicans, ibis, and spoonbills.
The island has four biosphere reserves, Bundala, Hurulu Forest Reserve, the Kanneliya-
Dediyagala-Nakiyadeniya, and Sinharaja. Out of these, Sinharaja forest reserve is
home to 26 endemic birds and 20 rainforest species, including the elusive Red-faced
Malkoha, Green-billed Coucal and Sri Lanka Blue Magpie. The untapped genetic
potential of Sinharaja flora is enormous. Out of the 211 woody trees and lianas so far
identified within the reserve, 139 (66%) are endemic. The Total vegetation density,
including trees, shrubs, herbs and seedlings has been estimated to be around
240,000 individuals per hectare.

In addition, Sri Lanka is home to over 250 types of resident birds (see List). It has
declared several bird sanctuaries including Kumana. During the Mahaweli 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. However the country's forest cover,
which was around 49% in 1920, had been fallen to approximately 24% by 2009.

References from en.wikipedia.org/wiki/Sri_Lanka