Silent Valley National Park

Silent Valley forests show all the known characteristics of the tropical rain forests. These include:

• a great network of surface roots in physical contact with moist leaf litter, the root mat having a biomass of 18 g dry weight in 5000 M³.
• laurel type leaves with entire margin and with a drip-tip in the mesophyl, thick and leathery for emergent and relatively thin for the under storey species
• very thin bark, less than 6mm in thickness
• woody nature of leaflets and profusion of woody climbers and epiphytes
• multi layered tree species with stature of more than 60 M with a trunk typically slender and often buttressed at the base, the crown depth and width being low compared to the trunk height
• tree density and basal area are comparable to the richest tropical rain forests in other parts of the world
• multi layered nature of the forest with emergent species raising their heads above the general canopy layer, consequently imparting an undulating bumpy look to the surface

The number of tree species computed for the Silent Valley (118 vascular plants of 84 species in 0.4 ha) is very high compared to a range of 60 to 140 species that characterise the other known tropical forests. The Alpha Diversity Index is 4.8, which is the same as that of another well known tropical rain forest, Barro Colorado Islands in Panama Canal. Zoological Survey of India had conducted faunal survey in 5 different locations. The specimens were sorted out into species and the groups compared. The levels of diversity in the Silent Valley were found to be much higher than those of the other areas.

The limited studies of the fauna of Silent Valley reveals that its rich resources as rare and unique – rare because many species which originally inhabited the entire belt of the Western Ghats have been lost due to destruction of their habitat by human beings or for other reasons. These faunal resources however are still available in Silent Valley, because of the relatively little human intrusion. It is unique because what little has been collected and studied has already proved to be of immense scientific interest from the taxonomic, zoogeographic and ecological points of view.
A number of species, which were available in the Western Ghats 50 to 100 years ago and which have not been recorded subsequently, still exist in Silent Valley. They include insects, fishes, amphibians, reptiles and mammals. Type specimens of these, described earlier by scientists, have been deposited in museums outside India. Even prototypes are not available in India for referral studies.