British NVC community W17
# British NVC community W17

NVC community W17 (Quercus petraea - Betula pubescens - Dicranum majus woodland) is one of the woodland communities in the British National Vegetation Classification system. It is one of the six communities falling in the "mixed deciduous and oak/birch woodlands" group.

This is a widely distributed community in northern and western Britain and represents mossy deciduous woodland of the uplands. There are four subcommunities.

## Community composition

Two constant species are found in the tree canopy of this community:

* Sessile oak (Quercus petraea)
* Downy birch (Betula pubescens)

Eight constant species are found in the field and ground layers of this community:

* Wavy hair grass (Deschampsia flexuosa)
* Greater fork-moss (Dicranum majus)
* Glittering wood-moss (Hylocomium splendens)
* Waved silk-moss (Plagiothecium undulatum)
* Red-stemmed feather-moss (Pleurozium schreberi)
* Bank haircap moss (Polytrichum formosum)
* Little shaggy-moss (Rhytidiadelphus loreus)
* Blueberry (Vaccinium myrtillus)

Rare species associated with the community include Hymenophyllum wilsonii and a number of oceanic bryophytes.

## Distribution

This community is widespread throughout upland areas of Britain. The subcommunities show some geographical localisation with W17a predominantly western and W17d predominantly eastern.

## Subcommunities

There are four subcommunities:

* W17a : the Isothecium myosuroides-Diplophyllum albicans subcommunity
* W17b : the so-called typical subcommunity
* W17c : the Anthoxanthum odoratum-Agrostis capillaris subcommunity
* W17d : the Rhytidiadelphus triquetrus subcommunity
