Sound Heath

Grassy heathland and scrub

Lowland heath (heathland below 300 metres elevation) is an internationally scarce habitat which is rare within Cheshire.[10] A survey in 1995 found only 60 Ha in the administrative county, of which as little as 11 Ha were wet heath.[11] Sound Heath is one of only four lowland heath SSSIs in the county.[10]

In the areas of damp heath, the predominant species when the site was designated an SSSI in 1963 were common heather (Calluna vulgaris), cross-leaved heath (Erica tetralix), common gorse (Ulex europaeus), western gorse (U. gallii) and purple moor grass (Molinia caerulea). These areas also of bog moss (Sphagnum).[2] A total of 50 species of bryophytes have been recorded at the site, including the large white-moss (Leucobryum glaucum), which is rare in Cheshire.[2][3] Other locally rare species that have been observed here include bog asphodel (Narthecium ossifragum), common lousewort (Pedicularis sylvatica) and round-leaved sundew (Drosera rotundifolia).[2][3]

The drier areas of heath have a grassy character, with typical species being matgrass (Nardus stricta) and wavy hair-grass (Deschampsia flexuosa).[2] Common tormentil (Potentilla erecta), dovesfoot cranesbill (Geranium molle), heath bedstraw (Galium saxatile), heath milkwort (Polygala serpyllifolia) and heath rush (Juncus squarrosus) have also been recorded, as has the locally rare bird's-foot (Ornithopus perpusillus) and shepherd's cress (Teesdalia nudicaulis).[2][3][12]

During the late 20th century, the area of heathland has been substantially reduced by the encroachment of scrub, birch, alder and willow.[2][5] The incursion of trees has caused the heath to become drier, resulting in the loss of some wet heath plants, including bog asphodel and round-leaved sundew.[13]

One of many small woodland ponds

The wetland habitat at Sound Heath is very diverse, ranging from small ponds and damp hollows to Sound Pond (SJ619480), which is nearly 60 metres in length.[14] Water bodies are found both in the sunny open heath areas and within the woodland.[2] As the pools result from the extraction of sand, they have a different ecology from the more common marl-pits, as well as from the glacial kettle holes and salt-subsidence flashes of the Cheshire Plain. Most have reached the late succession (mature) stage.[10] Although the encroachment of trees on the common has led to some ponds becoming infilled with leaf debris, reducing the number of permanent pools, the resultant seasonal wet areas support several rare plant species.[13]

The pools provide a habitat for a wide range of emergent plants, of which the rarest is bog St John's-wort (Hypericum elodes), previously believed to have died out in Cheshire. The locally rare floating club rush (Eleogiton fluitans) has been recorded at the site. Other wetland species observed here include bogbean (Menyanthes trifoliata), garlic mustard (Alliaria petiolata), greater spearwort (Ranunculus lingua), lesser celandine (Ranunculus ficaria), marsh cinquefoil (Potentilla palustris), marsh marigold (Caltha palustris), marsh pennywort (Hydrocotyle vulgaris), marsh thistle (Cirsium palustre), marsh violet (Viola palustris), reedmace (Typha), water violet (Hottonia palustris) and wavy bittercress (Cardamine flexuosa).[2][3][12]

The woodland predominantly dates from the past 40 years, although there are some mature oaks and other trees. The main species are common alder (Alnus glutinosa), pedunculate oak (Quercus robur), silver birch (Betula pendula) and willow (Salix), with common bramble (Rubus fruticosus) predominant in the undergrowth.[2]

Migrant hawker dragonfly

The mature pools of Sound Heath form one of the most important sites in Cheshire for freshwater invertebrates.[3][10] The mud snail (Omphiscola glabra),[2] Enochrus isotae species of water scavenger beetle[2] and the great raft spider (Dolomedes plantarius),[3] which are rare or endangered in the UK,[2][15] are among the many species that have been recorded in the site's ponds. Locally rare pond dwellers include the caseless caddisfly (Holocentropus stagnalis) and the diving beetle (Hygrotus decoratus).[2]

Dragonflies and damselflies are common, with 15 species recorded, two-thirds of which are known to breed here. Species include the broad-bodied chaser (Libellula depressa), common hawker (Aeshna juncea), emperor (Anax imperator) and ruddy darter (Sympetrum sanguineum), as well as the first Cheshire sighting of the migrant hawker (Aeshna mixta).[2][3]

The beautiful snout moth (Hypena crassalis), a scarce moth species in the UK, has been recorded at the site.[3] The open heath and grassland no longer forms a breeding site for the small heath butterfly (Coenonympha pamphilus), whose numbers are declining in the UK.[2][16]

Sixty species of spider have been recorded at the site.[3]

Sparrowhawk

Sound Heath forms an important breeding site for a wide range of birds. Locally rare species include the Eurasian sparrowhawk (Accipiter nisus) and the willow tit (Parus montanus).[2] Among the other species that have been observed here are the moorhen, reed bunting, turtle dove and willow warbler, the tawny, little and barn owls, and the greater spotted, lesser spotted and green woodpeckers.[3][13]

The heathland is a significant local habitat for the common lizard (Zootoca vivipara) grass snakes (Natrix natrix), and slowworms (Anguis fragilis) dominate the mats in the grassland in spring-time.[2][3] The common newt (Lissotriton vulgaris), common toad (Bufo bufo) and common frog (Rana temporaria) all inhabit the ponds,[13] and the high insect numbers associated with the water attract bats, such as the common pipistrelle (Pipistrellus pipistrellus) and common long-eared bat (Plecotus auritus).[10][13]