Various heather species dominate the areas immediately above the tree line, from 3,400 to about 3,800 m altitude. Heathers in the genera Erica and Philipia cover all but the inundated valley bottoms. These plants will grow to over 5 m in height, but only exhibit this in a few places in the mountains. This vegetation is repeatedly burnt by local people, mainly to make the area more accessible and generate plants of a height that can be browsed by livestock. As a result the plants are rarely more than 1.5 m in height, and often much less.

Mature heather stands exhibit a good grass and herb layer beneath the canopy. Frequently burnt areas have a poor ground cover, of low species diversity.