|IPA Factsheet - Arnecliff and Park Hole Woods|
Site Description There appear to be 501-1000 T. speciosum individuals on this site (JNCC, 2006, link: http://www.jncc.gov.uk/protectedsites/sacselection/n2kforms/UK0030142.pdf ). This site is described as “one of only four known outstanding localities in the United Kingdom, which is known from 15 or fewer 10 x 10 km squares in the United Kingdom” (JNCC, 2006, above link), i.e. nationally rare. There has been extensive disturbance in the past to these woodlands for both iron workings and woodland management. There are abundant rocks and small cliffs and a generally uneven topography, which has allowed important ferns to survive in an undisturbed state. Extensive collecting of one of these ferns in the past has led to its near-extinction at a number of sites in Britain (JNCC, 2006, see above link).
Botanical Significance Noted for vascular interest. The site consists of East Arnecliff Wood, running east to west, and part of Park Hole Wood, running north to south. These two areas are ancient semi-natural woodlands. Additionally, it includes part of West Arnecliff wood, which also runs from north to south. This area contains a mixture of ancient semi-natural and ancient replanted woodland (Plantations on Ancient Woodland Sites: PAWS). These woods are an important feature of Glaisdale valley, which lies around the River Esk. The site is in a hilly, upland region, and contains a valley. The soil is acidic, and the site rests over sedimentary rock (JNCC, 2006, above link). The woodland community includes upland oak woodland on acidic soils (91A0 Old sessile oak woods with Ilex and Blechnum in the British Isles). This habitat type covers approximately 17 % of the site. Such coverage is described as “significant” (JNCC, 2006, see above link). However, this is not a primary reason for SAC selection (JNCC, n.d.) or IPA selection. East Arnecliff wood rises steeply on the southern bank of the River Esk. Pedunculate oak (Quercus robur), rowan (Sorbus aucuparia) and birch (Betula sp) are widespread and abundant. Wych elm (Ulmust glabra) is locally frequent, and there is a widespread shrub layer of hazel (Corylus avellana), some holly (Ilex aquifolium)and occasional hawthorn (Crataegus monogyna). The upper acidic parts have widespread wavy hair grass (Deschampsia flexuosa), with greater woodrush (Luzula sylvatica), hairy woodrush (L. pilosa), bilberry (Vaccinium myrtillus), scattered heather (Calluna vulgaris), hard fern (Blechnum spicant) and mosses. This area contains a few shallow pools.West Arnecliff Wood is contiguous with East Arnecliff Wood. The wood rises steeply up from Glaisdale beck and is west facing. Park Hole Wood is a mixed deciduous wood occupying a moderately steep-sided south-facing valley. There is a mixture of mature and sub-mature Quercus sp and Betula sp. Alder (Alnus glutinosus) is scattered near the beck. C. avellana is widespread in the shrub layer with scattered or locally frequent I. aquifolium, C. monogyna and blackthorn Prunus spinosa. The herb layer is moderately diverse and includes hard shield fern Polystichum acuteatum, tufted hair grass Deschampsia cespitosa, and sedges Carex sp. The woodland lies adjacent to watercourses, and there are several springs among the rocky areas, which provide damp, sheltered and shaded conditions in which a rich fern and moss flora thrives. This flora includes the locally rare species Tunbridge filmy fern (Humenophyllum tunbrigense) and hay scented buckler fern (Dryopteris aemula). The regionally rare wood fescus grass (Festuca altissima) is also present on this site (Natural England, n.d., link: http://www.sssi.naturalengland.org.uk/citation/citation_photo/2000446.pdf ). Of particular interest is a large population of the Killarney Fern Trichomanes speciosum, an internationally rare species.
General Habitat Description Woodland and forest (major)Mire, bog and fen (minor)Mixed woodland (72.9%)Broad-leaved deciduous woodland (17.1%)Fens (4%)Permanent snow and ice (4%)??Inland water bodies (standing water, running water) (2%)Bogs, marshes, water fringed vegetation, inland rocks, screes, sands (JNCC, n.d., link: http://www.jncc.gov.uk/protectedsites/sacselection/sac.asp?eucode=uk0030142 ) Land use: Nature conservation/Research
Conservation Issues Forestry Commission considering restoring native stands in PAWS area.T. speciosum is vulnerable to any changes to its habitat and microclimate and changes to the flow or chemical composition of the water (JNCC, n.d. 1421 Killarney fern, link: Trichomanes speciosum