Plant Life

The vegetation of Sinharaja may be described either as a Tropical Lowland Rain Forest or Tropical Wet Evergreen Forest. Some striking characteristics of the forest are the loftiness of the dominant trees, the straightness of their bole, the abundance of regeneration and the diversity of species. The average height of the trees varies between 35m -40m. Some individuals rise even upto 50m.

Contrary to popular belief scrub growth does occur on rck oshelves or gaps on the canopy created by falling of over-mature trees. The great diversity of species of Sinharaja forest makes it difficult to distinguish ecological patterns. However, some tree associations have been recognized and these are the Dipterocarpus (Hora-Bu Hora) an association confined to the lower elevations along the Gin Ganga valley and the Mesua-Doona (Shorea) association forms the matrix of the Sinharaja forest.

The vegetation of Sinharaja is that of humid wet evergreen forest type with a high degree of endemism. In fact some families such as Dipterocarpaceae show an endemism more than 90%. 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. Similarly, high levels of endemism are perhaps true for the lower plants like ferns, Epiphyts as well. Out of 25 general endemic to Sri Lanka 13 are represented in Sinharaja.

The total vegetation density, including trees, shrubs, herbs and seedlings has been estimated to be around 240,000 individuals per hectare, of which 95% comprise individuals of the ground layer below 1m in height. The density of trees, lianas above 30cm girth at breast height, ranges between 600-700 individuals/ha. While the number of merchantable individuals of trees of girth greater than 150cm. Ranges between 45-55 individuals/ha.