The dominant natural vegetation of the area is characteristic of Lower Montane Wet Evergreen Forests while its species composition is typical to what is found in a mid-elevation primary rainforest. The presence of species habitats on different layers of the canopy clearly indicates a healthy forest ecosystem at work.
Towering Shorea trapezifolia and Shorea gardenineri form the pillars of the forest formation with Myristica dactyloides, Cullinia rosayroana, Bhesa montata, Alixnandra zeylanica filling in at different levels of the canopy.
Each layer of the forest canopy has a unique set of environmental conditions and organisms. The emergent layer comprises of tall trees such as Shorea congestiflora, Sorea stipularis, Shorea affinis soaring as high as 45m above the forest floor inhabited by eagles, monkeys, butterflies and insect-eating bats.
Underneath, rising up to about 35m, Shorea distichta and Shorea megistophylla (some of the species in the primary canopy layer) form the primary canopy layer. Many species of flower simultaneously giving habitat to Monkeys, Flying Squirrels, Bats, Tree Frogs, Ants, Beetles and birds such as Flycatchers.
The sub-canopy at 25m is home to a large concentration of insects. The plant species at this layer shields the exposed soil to create a microhabitat for forest regeneration. The ground layer referred to as the lowest stratum is composed of many rare and endemic herbal plants.
All these species are characteristic of low and mid-elevation primary rainforests. Ephiphytic mosses and liverworts, orchids and ferns, some of them extremely rare, adorn the floor of the forests as well as the tree trunks, confirming yet again the good health of the forest.
The Sinharaja Forest Reserve represents Sri Lanka’s only rainforest and is a living repository of a pristine ecosystem. The forest’s high biodiversity includes flora endemic to the country as well as some endemic to the forest itself.
Baseline studies conducted by USAID with reputed environmentalists Prof. Sarath Kotagama and Prof. Nimal Gunatilleke on fauna and flora around the lodge area are available.
Many rare and globally threatened species of fauna and flora underscore the reason why Sinharaja is a Man and Biosphere Forest Reserve and enjoys the status of a World Heritage Site.
The Rainforest ecolodge which consists of 16 Chalets is located at the border of the Sinharaja World Heritage Site. Therefore many endemic and globally threatened species have been recorded and can be observed in and around the area.
Eg: Sri Lanka Blue Magpie, Loris Massmulla, Giant Squirrel, Toque Monkey, Fishing Cat, And Asian Elephant.
The vegetation of Sinharaja may be described either as a tropical lowland rainforest 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.
Average height of the trees varies between 35m – 40m while some rise even up to 50m. 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 of 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 and epiphytes. Out of 25 genera endemic to Sri Lanka 13 are represented in Sinharaja.