The Serra dos Ancares is generally characterised by important areas of forest, located on the shady north-facing slopes of the mountains, and which are home to durmast oak (Quercus petraea), silver birch (Betula pubescens) and holly trees (Ilex aquifolium), with an important understory and related species such as the hazel (Corylus avellana) and the mountain ash (Sorbus aucuparia). The sunny south-facing slopes, however, have suffered significantly from fire and forestry activity, although they still conserve a fine presence of forest land, mainly composed of oakwood (Quercus petraea in the dampest and/or highest regions), Quercus pyrenaica in the middle regions and Quercus robur in the areas of least altitude).
In the last few years, a significant initiative has been undertaken to regenerate the habitat in the southern-facing areas, mainly as part of the European Union’s LIFE Project. The most well- conserved forests on the southern-facing slopes can be found in Vilarello de Donís and Cañón de Rao. The valley bottom is generally home to important clusters of chestnut trees, dotted with numerous meadows. The lands lying above the forest areas represent a typical mountain habitat, populated by bilberry shrubs (vaccinium myrtillus) in Pionedo, Corno Maldito and Pena Rubia, and which are of vital importance for the fauna of the Ancares region.