Crich Chase site of SSI

Site Name: Crich Chase
County: Derbyshire
Status: Site of Special Scientific Interest (SSSI) notified under Section 28 of the Wildlife and Countryside Act 1981, as substituted by Schedule 9 to the Countryside and Rights of Way Act 2000.
Local Planning Authority: Amber Valley Borough Council, Derbyshire County Council
National Grid reference: SK 347528
Area:118.2 ha
Ordnance Survey Sheet: 1:50,000: 119 1:10,000: SK 35 SW
Notification Date: 15 August 2013

Map showing the Site of Scientific Interest at Crich Chase

Map showing the Site of Scientific Interest at Crich Chase

Reasons for notification:
Crich Chase supports a diverse mosaic of semi-natural habitats, including woodland, scrub and unimproved neutral and acid grasslands. It is of special interest by reason of the following nationally important features that occur within the wider habitat mosaic: woodland dominated by the National Vegetation Classification (NVC) types W10 pedunculate oak Quercus robur – bracken Pteridium aquilinum – bramble Rubus fruticosus woodland, W7 alder Alnus glutinosa – ash Fraxinus excelsior – yellow pimpernel Lysimachia nemorum woodland and W16 oak Quercus spp. – birch Betula spp. – wavy hair-grass Deschampsia flexuosa woodland, much of which is ancient semi-natural woodland; species-rich neutral and acid grasslands of the NVC types MG5 crested
dog’s-tail Cynosurus cristatus – common knapweed Centaurea nigra grassland and U4 sheep’s-fescue Festuca ovina – common bent Agrostis capillaris – heath bedstraw Galium saxatile grassland; and a rich assemblage of grassland fungi, in particular its waxcaps (Hygrocybe), fairy clubs (Clavariaceae) and pinkgills (Entoloma).

General description:
The site occupies a steep south-west facing ridge on the shales and sandstones of Millstone Grit overlooking the River Derwent near Ambergate.The site comprises a mosaic of habitats including long-established semi-natural woodland (much of which is recorded as ancient semi-natural woodland), and neutral and acid grasslands.

The majority of the site supports an extensive area of ancient semi-natural woodland forming one of the largest and most structurally diverse semi-natural woodlands remaining in the Derwent valley of Derbyshire and of interest being on the upland fringes of the Peak District. There is evidence of a long history of woodland cover on the site, with the Chase noted as forming a north-eastern outlier of the medieval hunting forest of Duffield Frith.

The woodland is structurally diverse and variable in tree cover, and comprises a mix of both dry and wet woodland types. It is generally characterised by pedunculate oak Quercus robur, silver birch Betula pendula and locally sycamore Acer pseudoplatanus on the upper slopes, with alder Alnus glutinosa, ash Fraxinus excelsior, downy birch Betula pubescens, and willow Salix spp. forming small distinct stands over flushed ground around streams and springs. Scattered through the woodland is a generation of aged, over-mature or ‘veteran’ trees that display signs of past coppicing or pollarding and which largely comprise pedunculate oak, birch, alder and sweet chestnut Castanea sativa.

Much of the woodland soil is acidic in nature and its associated field layer is typically species-poor, comprising varying amounts of bluebell Hyacinthoides non-scripta, creeping soft-grass Holcus mollis, bramble Rubus fruticosus agg., honeysuckle Lonicera periclymenum, greater stitchwort Stellaria holostea and bracken Pteridium aquilinum. Over less acid soils on lower slopes the field layer can be richer with abundant bluebell joined by ramsons Allium ursinum, wood-sorrel Oxalis acetosella, red campion Silene dioica, yellow archangel Lamiastrum galeobdolon, dog’s mercury Mercurialis perennis and wood avens Geum urbanum.

The uppermost slopes of the Chase are characterised by more open woodland stands on thinner soils, dominated by silver birch with scattered oak and occasionally sycamore and young rowan Sorbus aucuparia. Woodland cover across this area is much patchier and here the field layer is dominated by bracken, wavy hair-grass Deschampsia flexuosa and broad buckler-fern Dryopteris dilatata. There is typically little under-storey here, although occasionally holly Ilex aquifolium, hawthorn Crataegus monogyna or younger trees occur. The topography of the steep upper slopes is rugged and in places punctured by rocky gritstone outcrops and large boulders where there are some dense stands of great wood-rush Luzula sylvatica with more occasionally hairy wood-rush L.pilosa. Heath bedstraw Galium saxatile, climbing corydalis Ceratocapnos claviculata and wood sage Teucrium scorodonia are particularly associated with these stands.

Additional structural diversity is provided by young stands of naturally regenerating woodland colonising abandoned fields, consisting mostly of silver birch, pedunculate oak and hawthorn but with crab apple Malus sylvestris locally. Much of the remaining open areas are covered by dense bracken over bluebell, creeping soft-grass and bramble, interspersed with small areas of remnant  neutral grassland which support a range of grasses such as red fescue Festuca rubra, common bent Agrostis capillaris and crested dog’s-tail Cynosurus cristatus, with common sorrel Rumex acetosa, tormentil Potentilla erecta, lesser stitchwort Stellaria graminea and sheep’s sorrel Rumex acetosella. Small, fragmented stands of wet woodland occur around minor watercourses and seepage zones, forming indistinct transitions with the surrounding drier woodland. The wet woodland is dominated by stands of alder Alnus glutinosa, which include old multi-stemmed trees, with downy birch, ash and oak. The shrub layer is not well-developed but does contain hazel Corylus avellana, grey willow Salix cinerea and guelder-rose Viburnum opulus. Aspen Populus tremula occurs rarely. The field layer is more diverse within these stands and alongside bramble, honeysuckle and creeping soft-grass are a distinctive range of wetland plants including opposite-leaved golden-saxifrage Chrysosplenium oppositifolium, remote sedge Carex remota, yellow pimpernel Lysimachia nemorum, soft-rush Juncus effusus, bugle Ajuga reptans, lady-fern Athyrium filix-femina and wild angelica Angelica sylvestris, plus the locally rare thin-spiked wood-sedge Carex strigosa. Bryophytes are also more prominent here and include overleaf pellia Pellia epiphylla (a liverwort) and the mosses, shining hookeria Hookeria lucens) and Chiloscyphus polyanthus.

Neutral and acid grassland
An extensive area of unimproved herb-rich neutraland acid grassland dominates the open south-facing slopes at the south-eastern extremity of the site, where it forms a close mosaic with scattered stands of hawthorn scrub and small patches of less rich semi-improved grassland.This vegetation is overall exceptionally species-rich, showing some distinctive and unusual transitions resulting from the acid, neutral and calcareous soil conditions derived from the diverse underlying geological strata. Typically the grassland is characterised by a diverse and rich range of native grasses and herbs. Grasses such as red fescue, crested dogs-tail, common bent, Yorkshire-fog Holcus lanatus and sweet vernal-grass Anthoxanthum odoratum all occur in abundance, with quaking grass Briza media, heath-grass Danthonia decumbens and sheep’s-fescue Festuca ovina occurring more locally. Also present throughout is a diverse range of characteristic herbs which include meadow vetchling Lathyrus pratensis, common knapweed Centaurea nigra, cowslip Primula veris, bird’s-foot-trefoil Lotus corniculatus, ribwort plantain Plantago lanceolata, glacuous sedge Carex flacca, betony Betonica officinalis, devil’s-bit scabious Succisa pratensis, rough hawkbit Leontodon hispidus, cat’s-ear Hypochaeris radicata, oxeye daisy Leucanthemum vulgare and yellow-rattle Rhinanthus minor. There are additional records of the locally uncommon adder’s-tongue fern Ophioglossum vulgatum. Of particular note is the juxtaposition of species characteristic of more acidic conditions, such as heath bedstraw, tormentil and heath milkwort Polygala serpyllifolia with species such as fairy flax Linum cartharticum and bee orchid Ophrys apifera, which are more typical of more alkaline soils.

The thinnest soils are characterised by small areas of parched rabbit-grazed acid grassland. Here grasses such as common bent, sweet vernal grass, heath-grass,red fescue, sheep’s fescue, Yorkshire-fog and creeping soft grass occur in abundance. A characteristic range of herbs indicative of acid grassland are also found including tormentil, sheep’s sorrel, heath bedstraw, field wood-rush Luzula campestris, heath wood-rush L.multiflora, wood sage, harebell Campanula rotundifolia, heath speedwell Veronica officinalis and mouse-ear-hawkweed Pilosella officinarum.

Towards the northern end of the site, at Thurlowbooth, Chadwick Nick and The Tors, there are other areas of unimproved neutral grassland which again form mosaics with areas of less rich semi-improved grassland. These grasslands are generally managed as hay meadow. Grasses such as sweet vernal-grass, common bent, red fescue, Yorkshire-fog and crested dogs-tail occur in abundance, with false oat-grass Arrhenatherum elatius, cock’s-foot Dactylis glomerata, yellow oat-grass Trisetum flavescens and quaking grass occurring less frequently. Herbs are well represented by species such as common knapweed, rough hawkbit, bird’s-foot-trefoil, cowslip, red clover Trifolium pratense, ribwort plantain,with species such as tormentil, oxeye daisy, meadow vetchling and yellow rattle occurring more locally. One field at Thurlowbooth Farm supports twayblade Listera ovata.

Assemblage of grassland fungi
The unimproved grassland vegetation is further distinguished by a rich assemblage of grassland fungi. Crich Chase is one of the few sites in Derbyshire to contain these types of unimproved grassland together with a rich fungal assemblage, and this is largely attributable to the lack of agricultural improvement and low nutrient status of the land, together with regular grazing by livestockand rabbits. The key groups of this fungal assemblage are the waxcaps (Hygrocybe), fairy clubs (Clavariaceae) and pinkgills (Entoloma). The waxcap diversity is exceptional, with 25 species recorded.

Species include the plum-red Hygrocybe punicea which is strongly indicative of unimproved grassland and is abundant in places, the orange-yellow H.aurantiosplendens, the brown H.colemanniana and the bright red H.calciphila, both of which are indicative of more calcareous soils. In addition, H.coccinea, a robust and sticky scarlet cap common in unfertilised pastures, the lime-yellow H.citrinovirens, the green parrot waxcap H.psittacina, and the pink ballerina waxcap H.calyptriformis also occur as part of this assemblage. There are 19 pinkgill species recorded including the scarce Entoloma exile, E.griseocyaneum, E.asprellum, E.catalaunicum and a notable population of the nationally rare big blue pinkgill E.bloxamii. The grassland fungi assemblage also contains 11 species of fairy club including the straw-yellow fairy club Clavaria straminea and the meadow coral Clavulinopsis corniculata.

In addition to the reasons for notification, the woodland supports an assemblage of moths known to include 140 species, of which 16 are considered locally rare or uncommon. One of these, the argent and sable Rheumaptera hastate, is listed as nationally scarce and is closely associated with stands of young birch in open sunlit conditions. The upper slopes of the woodland also host colonies of the northern wood ant Formica lugubris,a species which is closely associated with open old forest habitat and has a very local distribution in Britain and occurs at Crich Chase  towards the southern edge of its range in Great Britain. The flower-rich grasslands support butterflies including dingy skipper Erynnis tages, which has a localised distribution in Derbyshire