The Dehing Patkai region is bountifully rich in biodiversity. It falls under Indo- Burma hotspot, which is one of the twenty-five richest biodiversity hotspots of the world. The Indo-Burma hotspot comprises about 2 million square kilometers of tropical Asia, east of the Indian sub-continent.The region includes all of Cambodia, Laos, nearly the entire territories of Thailand, Myanmar and Bhutan,parts of Nepal,far eastern India and extreme south China,Hanian Islands in south China sea and Andman Islands. The region is still revealing its biological treasurers.Three-mammal species have been discovered in recent years.The hotspot has the world's highest diversity of fresh water turtle species.

The Digboi forest division falls under Indo-Burma biodiversity hotspot and it is situated in between 27° 15’ to 27° 30’ north longitude and 95° 25’ to 95° 45’ east latitude. The Digboi Division is also integral part of the Dehing Patkai Elephant Reserve with total area of 609.55 sq.km. and a total of 160 wild elephants. Recently Dehing Patkai Sanctuary has been notified with the total area of 116 sq. km., consisting of Upper Dehing (West Block) Reserved Forests, Dirok and Joyopore. The sanctuary is famous for many species such as Asian Elephant, Royal Bengal Tiger, Black Panther, Hoolock Gibbon, Leopard, Jungle Cat, Barking deer,Bison,Bear, Common Monkeys, Slow Loris , Flying Squirrel, Mongoose,Pangolin Great Indian Civet, Birds like Winged Wood Duck, Hornbill, Kingfisher, Woodpecker, Myna, Dove, green pigeon, Barbet, Bulbul, Vulture, Kite, Hawk, Owl, Bat, Giant Bat, varieties of cranes, Darter, Stork, Cormorant, Monitor Lizard, Python, Viper , Cobra and many more varieties of poisonous and non poisonous snakes.

The Upper Dehing Reserved forest is famous and is also known as rain forest. The entire forest of the Dehing-Patkai region houses many endemic species,and the forest are of multistoried types with five canopy layers. The first canopy is covered with luxuriant growth of Hollong,Titasopa and Borpat ec.. The second canopy consists of Nahar with Sam, Mekai, Amari, Kadam, Bhomora, Barhomthuri, Bhelkor, Bogipoma and Bhola. The third canopy is mainly dominated by Morhal, Ajar, Mej, Owtenga, Bajiow etc. The fourth canopy is mainly covered by woody shrubs like kaupat, Tora, Bogitora etc. Palms like Geruga, Tamul, Tokopat, tree ferns, cranes, woody climbers like oblonga are also common. The ground flora consists of various shrubs like Bon Moduriam, Bon posola, Dhopat tita, Digholti etc.