Artle Dale

Also within

Lancashire County Forest Of Bowland Scenic Area

Condition (Natural England)

Climate exposure

This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.

Habitats

Fast flowing river and stream

Geology & landscape

Geological Feature: Gorge / Ravine · Rock Type: Alluvium, Sandstone, Shale

Landscape processes: Coastal, Fluvial

Description

Area, 26.1 ha. 64.5 ac. Description Artle Dale is the wooded gorge of Artle Beck and is situated 7km east of Lancaster. It is of importance, as one of the two or three best valleys in Lancashire, for its bryophyte moss and liverwort communities, with over 160 species having been recorded. Of particular interest are excellent examples of base enriched cliff, stream side gorge and Atlantic woodland communities, the latter rare in Lancashire, all of which include species which are scarce in the county. Several of the communities and species in Artle Dale are approaching the south eastern limit of their range in Britain. The bryophytes of Artle Dale are therefore outstanding in a local context and also important nationally. Along this part of its length Artle Beck occupies a deep valley and is shaded and sheltered throughout by surrounding woodland. The banks vary from being shallowly sloping to vertical rock walls several metres high and there are a number of higher shale scars. A substantial amount of base rich flushing occurs on the banks. The range of habitats is reflected in the bryophyte flora, which is rich and includes several scarce species. Bryophytes are abundant and often luxuriant on rocks in the beck, on scars, in flushes and on alluvium. In the beck Scapania undulata, Hygrohypnum ochraceum, Fontinalis antipyretica and Racomitrium aciculare are common. On alluvium Dichodontium pellucidum, Rhizomnium punctatum and Chiloscyphus polyanthos are often abundant and Geheebia spadicea is locally frequent. Rock scars close to the stream have abundant Thamnobryum alopecurum, Hyocomium armoricum and Brachythecium plumosum, while shale scars and cliffs with extensive seepage and base enrichment have a characteristic flora including Palustriella commutatum, Eucladium verticillatum, Bryum pseudotriquetrum, Blindia acuta and the minute Seligeria pusilla. The central part of the gorge has areas of base rich sandstone with Ctenidium molluscum, Fissidens dubius and the liverwort Lejeunea cavifolia all occurring. Also present on rock here are the liverworts Lejeunea patens at its only Lancashire site and Saccogyna viticulosa, a strictly Atlantic plant very rare in Lancashire. Other scarce bryophytes found in this deep, humid central zone include Taxiphyllum wissgrillii, Rhynchostegiella teneriffae, Tetrodontium brownianum, Jamesoniella autumnalis and Odontoschisma denudatum. Leucobryum juniperoideum occurs at its only Lancashire site. Towards the east of the site is an area of boulder strewn woodland more reminiscent of a western Scottish ravine woodland, with a strongly Atlantic bryophyte flora. Species such as Scapania gracilis, Bazzania trilobata and Dicranodontium denudatum are common on rocks and in rock crevices and there is a good variety of ferns present.

Species mentioned

Plant communities