It harbours over 5000 plants, about 85 terrestrial mammals, over 500 birds and many butterflies, insects and reptiles.[56] At the lowest elevations, essentially at Arunachal Pradesh's border with Assam, are Brahmaputra Valley semi-evergreen forests. Much of the state, including the Himalayan foothills and the Patkai hills, are home to Eastern Himalayan broadleaf forests. Toward the northern border with Tibet, with increasing elevation, come a mixture of Eastern and Northeastern Himalayan subalpine conifer forests followed by Eastern Himalayan alpine shrub and meadows and ultimately rock and ice on the highest peaks.