Rajaji National Park , comprising of varied ecosystems like grasslands, river in forests and the slopes of the Shiwaliks make it a storehouse of floral and faunal diversity. The trees, shrubs, orchids, fungi, mammals, birds, amphibians, reptiles and insects make exploring the reserve an adventurous experience. Rajaji National Park represents floral elements of both the Himalayan and the Upper Gangetic Plains. Owing to its location between both these bio- geographic regions, it is home to one of the most diverse ranges of wildlife habitats in the country. The eight major forests types including the Western Gangetic Moist, Northern Dry Deciduous and Khair-Sissoo forests in the southern slopes, the Low Alluvial Savannah Woodlands in the southern margins of the reserve, and the Shiwalik Chir-Pine forests in the higher reaches of the hills makes this area rich of bio diversity.

The majestic sal along with its associates dominates most of the forests in the gentler northern slopes of Rajaji National Park. Some trees grow up to 80 ft with a girth of 5 ft. The sal trees shed their leaves between February to March and soon changes hues from brownish red to pale green to dark green. During March and April the forest is filled with the mild scent of the sal trees in full blossom. There are a lot of fruit bearing trees which are a treat to watch with several birds and animals feeding on them. The fruits of the harar and behera trees are eaten by birds and animals ranging from elephants to mice. Jamun, Chilla, Ber, Lassora, Aonla, Ficus, Bel, Sisham are few out of the 30 species of fruit-bearing trees found in reserve. Rajaji National Park also harbours some of the rare and threatened plants which include Catamixis baccharoides (Asteraceae), Eremostachys superba (Lamiaceae), Euphorbia fusiformis (Euphorbiaceae), gloriosa superba (Colchicaceae) etc.

Of these E. superba is one the most beautiful tuberous native species of the region and is known only from the area around Mohand. Other interesting species C. baccharoides, represented by a single species all the world is found on the steeply lower slopes of lower Shiwaliks. Tubers of E.fusiformis and G. superba are generally used for medicinal purposes. Since Rajaji is a rich repository of both floral and faunal elements, it is necessary to conserve these by inside conservation practices. Rajaji is a home to 36 species of orchids which is a reflection of the pristine habitat. One can find several species of fungi in the reserve. Their ability to re-cycle the food locked in dead and decaying matter offer conducive breeding ground for several insects such as moths and beetles which in turn have great relevance in maintain the balance of the ecosystem. Tiger population so only confined to Chilla and Gohri ranges and the buffer zone of the reserve.