Crookhill Brick Pit
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Condition (Natural England)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| SY644798 | — | Favourable | 4.66 | 2009-03-25 |
Habitats
Geology & landscape
Geological Period: Jurassic
Description
Crook Hill Brick Pit SSSI Description The site is a disused brickpit, which provides the best exposure of Lower and Middle Oxford Clay in southern England, showing a sequence through the jason, coronatum and athleta zones, of Middle Jurassic age. It is also a nationally important site because it supports an exceptional population of great crested newts Triturus cristatus. The SSSI includes the breeding ponds and the terrestrial habitat that is used by the newts for resting, foraging and hibernation. General description Crookhill Brick Pit is located three kilometres to the west of Weymouth. The site is situated on Oxford Clay. Geology This disused brickpit provides the best exposure of Lower and Middle Oxford Clay in southern England, showing a sequence through the jason, coronatum and athleta zones, of Middle Jurassic age. There are considerable differences in zonal thickness and lithology between this section and the sections in the Midlands, with the grossouvrei subzone being greatly expanded at Crookhill. The clays and shales seen here contain a rich fauna of ammonites, belemnites and bivalves, with the athleta zone fauna being particularly prolific and important. Reineckeid ammonites, usually rare in the British Callovian, occur fairly commonly in the athleta zone here. Crookhill is a key locality for British Callovian biostratigraphy. great crested newts The particular combination and juxtaposition of aquatic and terrestrial habitats provides ideal breeding, foraging and hibernation conditions for the great crested newt. Numbers of newts recorded on the site are exceptionally high for Dorset. The newts depend on water for breeding and particularly favour moderately deep, well-vegetated ponds without fish. The variety of water bodies on the site, which are largely rain-fed and hence of high water quality, provide extremely good conditions for newts. Reeds Phragmites australis dominate the aquatic vegetation of the pond margins and floating vegetation is mainly broad-leaved pondweed Potamogeton natans. During the first two or three years of life before breeding starts, and outside the spring breeding season, great crested newts are dependent on terrestrial habitats to provide foraging areas and places to hibernate. The terrestrial habitat consists of rough grassland, scrub and the remains of the former brickworks that provide valuable refugia for amphibians. The open grassland of the southern slopes is a mixture of false oat grass Arrhenatherum elatius, red fescue Festuca rubra and Yorkshire fog Holcus lanatus, with herbs characteristic of calcareous clay soils such as colt’s-foot Tussilago farfara and bristly ox-tongue Picris echoides. Other herbs scattered in this grassland include yellow wort Blackstonia perfoliata, creeping cinquefoil Potentilla reptans, bird's foot trefoil Lotus corniculatus, common knapweed Centaurium erythraea and grass vetchling Lathyrus nissolia. To the south of the clay pit a small remnant of old grassland has local plants of strawberry clover Trifolium fragiferum and pepper-saxifrage Silaum silaus. The scrub includes bramble Rubus fruticosus, elder Sambucus nigra, hawthorn Crataegus monogyna, willow Salix spp. and common gorse Ulex europaeus. The habitats that occur around the ponds on this site are as important as the presence of suitable ponds. In addition to the reasons for notification, the site also supports populations of smooth newt Lissotriton vulgaris, palmate newt Lissotriton helveticus, grass snake Natrix natrix, slow worm Anguis fragilis, common lizard Lacerta agilis and adder Vipera berus. Southern hawker Aeshna cyanea and scarce hawker dragonflies Aeshna mixta are also found on the site. Other Information: The great crested newt is listed in: • Annexes II and IVa of the European Communities Directive 92/43/EEC, on the conservation of natural habitats and of wild fauna and flora – the Habitats Directive • Appendix II of the Bern Convention • Schedule 5 of the Wildlife and Countryside Act 1981 • UK Biodiversity Action Plan priority species list This is a Geological Conservation Review (GCR) site.
Species mentioned
Show the 27 species mentioned in the description, with red-list statusPlant communities
W20 — Montane scrub
Salix lapponum-Luzula sylvatica scrub
Show 107 indicator speciesSalix arbuscula, Salix cinerea, Salix lapponum, Salix myrsinites, Salix phylicifolia, Salix reticulata, Empetrum nigrum, Calluna vulgaris, Salix lanata, Vaccinium myrtillus, Vaccinium uliginosum, Carex atrata, Carex bigelowii, Carex binervis, Carex flacca, Luzula multiflora, Luzula sylvatica, Huperzia selago, Selaginella selaginoides, Aulacomnium palustre, Mnium hornum, Philonotis fontana, Plagiomnium undulatum, Rhizomnium punctatum, Dicranum bonjeanii, Dicranum majus, Dicranum scoparium, Fissidens adianthoides, Racomitrium lanuginosum, Calliergonell cuspidatum, Ctenidium molluscum, Hylocomium splendens, Hypnum callichroum, Hypnum cupressiforme, Palustriella commutatum, Plagiothecium denticulatum, Plagiothecium undulatum, Pleurozium schreberi, Ptilium crista-castrensis, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Rhytidiadelphus triquetrus, Sanionia uncinata, Scorpidium revolvens, Thuidium tamariscinum, Atrichum undulatum, Polytrichastrum alpinum, Sphagnum capillifolium, Sphagnum fallax, Sphagnum girgensohnii, Sphagnum palustre, Sphagnum russowii, Sphagnum squarrosum, Sphagnum subnitens, Sphagnum teres, Barbilophozia barbata, Chiloscyphus polyanthos, Diplophyllum albicans, Lophocolea bidentata, Plagiochila porelloides, Ptilidium ciliare, Scapania undulata, Cladonia squamosa, Peltigera canina, Angelica sylvestris, Caltha palustris, Hieraclium spp., Saussurea alpina, Solidago virgaurea, Campanula rotundifolia, Succisa pratensis, Valeriana officinalis, Rhodiola rosea, Vaccinium vitis-idaea, Thymus praecox, Epilobium anagallidifolium, Dactylorhiza viridis, Euphrasia officinalis, Rhinanthus minor, Oxalis acetosella, Oxyria digyna, Polygonum viviparum, Rumex acetosa, Anemone nemorosa, Ranunculus acris, Thalictrum alpinum, Alchemilla alpina, Alchemilla glabra, Filipendula ulmaria, Geum rivale, Galium boreale, Galium saxatile, Saxifraga aizoides, Saxifraga hypnoides, Saxifraga oppositifolia, Saxifraga stellaris, Viola riviniana, Agrostis canina, Agrostis capillaris, Anthoxanthum odoratum, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Festuca rubra, Nardus stricta, Dryopteris dilatata, Phegopteris connectilis
W21 — Hedgerow scrub, Mixed scrub
Crataegus monogyna-Hedera helix scrub
Show 81 indicator speciesHedera helix, Salix cinerea, Acer pseudoplatanus, Ilex aquifolium, Betula pendula, Corylus avellana, Fagus sylvatica, Quercus robur, Fraxinus excelsior, Malus sylvestris, Sorbus aria, Taxus baccata, Ulmus glabra, Ulmus procera, Sambucus nigra, Viburnum lantana, Euonymus europaeus, Cornus sanguinea, Juniperus communis, Ligustrum vulgare, Clematis vitalba, Rhamnus cathartica, Crataegus laevigata, Crataegus monogyna, Prunus spinosa, Juncus effusus, Plagiomnium undulatum, Brachythecium rutabulum, Kindbergia praelonga, Rhynchostegium confertum, Tamus communis, Heracleum sphondylium, Torilis japonica, Arum maculatum, Arctium minus, Cirsium arvense, Lonicera periclymenum, Moehringia trinervia, Silene dioica, Stellaria graminea, Stellaria holostea, Stellaria media agg., Calystegia sepium, Mercurialis perennis, Geranium robertianum, Iris foetidissima, Glechoma hederacea, Lamium purpureum, Origanum vulgare, Stachys sylvatica, Teucrium scorodonia, Allium ursinum, Hyacinthoides non-scripta, Circaea lutetiana, Rumex sanguineus, Anemone nemorosa, Ranunculus repens, Fragaria vesca, Geum urbanum, Potentilla sterilis, Poterium sanguisorba, Rosa arvensis, Rosa canina, Rubia peregrina, Rubus fruticosus agg., Galium aparine, Urtica dioica, Viola riviniana, Anisantha sterilis, Arrhenatherum elatius, Brachypodium pinnatum, Brachypodium sylvaticum, Bromopsis erecta, Dactylis glomerata, Elytrigia repens, Holcus lanatus, Holcus mollis, Poa trivialis, Asplenium scolopendrium, Pteridium aquilinum, Dryopteris filix-mas
W22 — Hedgerow scrub, Mixed scrub
Prunus spinosa-Rubus fruticosus scrub
Show 49 indicator speciesHedera helix, Acer campestre, Corylus avellana, Ulex europaeus, Prunus spinosa, Plagiomnium undulatum, Brachythecium rutabulum, Eurhynchium striatum, Kindbergia praelonga, Thuidium tamariscinum, Atrichum undulatum, Lophocolea bidentata, Achillea millefolium, Cardamine flexuosa, Lonicera periclymenum, Moehringia trinervia, Silene dioica, Silene uniflora, Stellaria media agg., Mercurialis perennis, Geranium robertianum, Stachys sylvatica, Teucrium scorodonia, Hyacinthoides non-scripta, Oxalis acetosella, Digitalis purpurea, Plantago lanceolata, Veronica chamaedrys, Armeria maritima, Rumex acetosa, Filipendula ulmaria, Geum urbanum, Rosa canina, Rubus fruticosus agg., Rubus idaeus, Galium aparine, Urtica dioica, Viola riviniana, Agrostis capillaris, Brachypodium sylvaticum, Dactylis glomerata, Festuca rubra, Holcus lanatus, Holcus mollis, Poa trivialis, Asplenium scolopendrium, Pteridium aquilinum, Dryopteris borreri, Dryopteris filix-mas