Dartmoor is of international importance for its blanket bogs, upland heaths and oakwoods, and of at least national importance for its valley mires and grass moor. Wistman’s Wood, north of Princetown, is a National Nature Reserve. Other notable habitats include hay meadows and hedgebanks, granite tors, torrent rivers and lowland heath. 28 species for conservation have been identified including some which are rare, such as lichens and butterflies, and some which are popular though still widespread, such as the dormouse, buzzard and wild daffodil.

The Tamar and Tavy estuaries embrace a large Site of Special Scientific (1441 hectares) which is also a candidate for EU Special Area of Conservation status. The shallow inlets and bays, estuaries and sub-tidal sandbanks contain many specialised habitats and species. There is another, smaller SSSI in Grenofen Wood and West Down (102 hectares) on account of the diverse lichens and declining high brown fritillary butterfly population.

More widely, rivers and streams and other woodlands are also important, with hedgerows providing an exceptionally important wildlife resource. Species for conservation action include the dormouse, otter, skylark, marsh fritillary and freshwater pearl mussel.

The Plymouth to Bideford road is generally regarded as the western limit of the English Elm population, being replaced westwards by the Cornish Elm.

Both Dartmoor and the area of West Devon Pasture support important geological and geomorphological features such as tors and clitter slopes.