The Geopark is home to a wide variety of woodland.
Small stands of broadleaved are comprised of a mixture of oak, silver birch, brown birch and ash while alder predominates on valley floors. The stands are an important habitat for breeding migrants from Africa including the chiffchaff, pied flycatcher, redstart, willow warbler and blackcap.
Broadleaved upland woods
These occur particularly on the steep valley slopes of the Nedd and Mellte gorges and comprise humid close canopy oak woodlands with important moss populations.
Coniferous forestry has been developed on slopes and can extend up to the hill summits. These forests provide habitats for the goshawk, redpoll and siskin.