The variety of habitats at Muir of Dinnet culminate in an impressive range of wildlife and plant species being recorded at the reserve. Approximately 470 ha of the reserve is woodland, with birch dominating the lower ground and Scots pine forest on the higher slopes. Isolated examples of rowan, willow, alder, and junipers are also found, along with 4.5 ha of aspen woodland. This woodland, which lies between Old and New Kinord, is one of the largest stands of aspen in Scotland, and supports Scotland's largest population of the rare aspen bristle-moss, as well as rare fungi such as aspen bracket fungus and Junghuhnia nitida. Dry heathland consisting chiefly of heather and bearberry covers 42 ha of the reserve; this habitat also supports plant species such as intermediate wintergreen, petty whin and stone bramble as well as over 30 species of Cladonia lichen. There are also two areas of raised bog, which support plants such as sedges and many species of sphagnum moss.