Dr M’s Botany bus Diary – Day 5 Wistmans Wood, Dartmoor

Day 5 of Dr M’s University of Reading MSc Plant Diversity field course and our eXtreme botanists head from the coast of Dorset to Cornwall making a diversion through the uplands of Dartmoor, and a stop off at Wistman’s Wood – a rare relict example of the ancient upland woodlands of Dartmoor.

Wistman’s Wood, situated amidst acid grassland heath and bog, is a famous botanical site situated on the lower west-facing slopes of the West Dart Valley at an altitude of around 400 metres and is an outstanding example of native upland oak woodland developed on soils derived from the hard acid rocks of south-western Britain including granites.

The wood is dominated by Pedunculate Oak (Quercus robur) and the trees have a gnarled
and twisted growth-form, many with their lower branches resting on the granite rocks which
forms the woodland floor.

Other trees include Rowan (Sorbus aucuparia), Holly (Ilex aquifolium) and the field layer includes Creeping Soft Grass (Holcus mollis), Great Woodrush (Luzula sylvatica) and Bramble (Rubus fruticosus) and in the canopy is the epiphytic Polypody fern (Polypodium vulgare) and Bilberry (Vaccinium myrtillus) which also behaves as an epiphyte here!

In the British National Vegetation Classification (NVC) the the woodland fits the upland Oakwood type W17 Quercus petraea-Betula pubescens-Dicranum majus woodland, and the W17a sub-community Isothecium myosuroides-Diplophyllum albicans sub-community, even though the main tree is the lowland Quercus robur not the more upland type Quercus petraea.

The epiphytic flora is luxuriant, and bryophytes are well represented, including Isothecium myosuroides, Plagiothecium undulatum and Rhytidiadelphus loreus and the clean air lichens such as Usnea articulata and other Usnea spp.

Examples of mosses at Wistmans Wood:

Examples of Lichens at Wistmans Wood:

The whole valley is open to grazing by sheep, cattle and ponies, with the exception of a small fenced area of the wood which provides an interesting ecological comparison of grazed and ungrazed woodland.