The ASNP represents a large number of plants and animals unique to the high altitude shola-grassland vegetation. The Mannavan Shola is the largest shola forest patch in South India. The giant fern, Cyathia crinita reaching to upto 6m height is a unique character of Mannavan Shola. Out of 543 species of pteridophytes and angiosperms recorded in Mannavanshola, nearly 20% (109 species) are ‘endemic’ and 25% (128 species) classified as ‘rare’ and another 26 species are considered to be in a ‘threatened state’. Two rare Pteridophytes namely, Elaphoglossum stelligerum Sledge and Pleopeltis macrocarpa (Bory ex Willd.) that have been collected by Kaulf from Mannavanshola are new records to Kerala (Kumar, 1997). About 11 species of fungi are recorded from this Shola of which Collectotrichum acutatum is a new record to Kerala. The endemic and elusive Nigiri marten (Martes gwatkinsii) is found in the Park. Out of the 16 endemic birds of Western Ghats, 9 are reported from the Park.
The Park provides the only source of water not only for the tribal hamlets within, but also for the inhabitants of Kanthallur, Puthur, Perumala, Pazhathottam and Silandiyar. The Park also has unique features and provides ample academic opportunities for studying the biodiversity of montane vegetation and the ecological roles associated with the ecosystem. It can also serve as a field laboratory for activities like conservation education, research and monitoring and participatory management.