The ecoregion is a biodiversity hotspot, due to its location at the meeting zone of major floristic zones: Assam-Indian, Eastern Himalayan, Indo-Malayan, and Chinese. The remoteness, relatively low human population, and isolation have also contributed to the area's ecological preservation. Most of the area is covered in closed forest - 80% broadleaf evergreen and 15% needle-leaf evergreen. Altitude zonation is important: below 2,400 meters Indo-Malayan species are dominant, while Indo-Himalayan are found mostly above. Below 915 meters the forests are
tropical rainforest trees of genus
Magnoliaceae,
Lauraceae, and
Dipterocarpaceae. Above that are trees of genus
Fagaceae, and
Meliaceae, plus some tree ferns and climbing palms. Trees in mature forests are typically draped in
lianas. Over 140 species of mammals, and 370 species of birds are known in the ecoregion. The large un-fragmented forests are valuable for supporting large mammals, including the endangered Tiger
Panthera tigris, the endangered Red panda
Ailurus fulgens, the endangered Asian elephant
Elephas maximus, and vulnerable Takin
Budorcas taxicolor. == Protected areas ==