Asham Wood

Also within

Somerset County

Condition (Natural England)

Habitats

Coppiced woodland

Geology & landscape

Geological Feature: Rock Outcrop · Mining / Industrial: Quarry · Geological Period: Carboniferous, Devonian · Rock Type: Limestone

Birds & fish recorded

Birds

Description

Area, 140.6 hectares 347.5 ac Description Asham Wood is the largest and most diverse of the ancient semi natural woods in the Mendips. Despite recent partial destruction due to quarrying it remains one of the most important. The wood occupies two deep valleys and the intervening plateau. Most of the underlying rocks are calcareous Carboniferous Limestones and Shales, but Devonian Portishead Beds outcrop along the northern valley. The soils are neutral to strongly alkaline over the limestone, but mildly acid over the Devonian beds. Unlike other Mendip ancient woods the soils include a full range from excessively drained skeletal soils on the limestone outcrops to permanently wet conditions along the streamside. Mostly, however, the soils are freely drained clay loams with a degree of flushing along the lower slopes of the valleys. Several woodland types occur within the wood. On the heavy acid soils of the northern valley slopes one finds acid pedunculate oak hazel ash woodland. Along the valley bottom the alder Alnus glutinosa is mostly on neutral alkaline mineral soils, but in parts of the southern valley alder wood was more extensive and wet and is classified as base rich springline alder wood. On the limestone plateau and slopes the woodland is a mixture of dry ash maple woodland and maple ash lime woodland. The latter being more abundant south of Tunscombe Bottom. Both these types are particularly characteristic of Mendip woodlands and indeed are better developed here than elsewhere in Britain. Finally, on the steep slopes of Tunscombe Bottom and Leighton Hanging wych elm Ulmus glabra is present and generates a further type, calcareous ash wych elm woodland. This is found both on the flushed lower slopes and on rock outcrops, where yew Taxus baccata is abundant. This range of woodland types is greater than in other Mendip ancient woods and it includes the two types of nationally limited distribution which are especially characteristic of this area. All these woodland types have long been treated as coppice with standards, a system which seems to have finally died out here as late as 1950. The principal feature of interest is the abundance of stub and small pollards of pedunculate oak Quercus robur, ash Fraxinus excelsior, field maple Acer campestre and small leaved lime Tilia cordata. Indeed, pedunculate oak in particular is a complete mixture of all treatment forms, standards of maiden origin, pollards, stubs and low cut coppice. A similar structure can be seen in other Mendip ash lime woods, but not as well developed as at Asham. Within the coppice system shrubs survived as opportunists in clearings and many are now widespread, notably, guelder rose Viburnum opulus, wayfaring tree Viburnum lantana, dogwood Cornus sanguinea and spindle Euonymus europaeus. Holly Ilex aquifolium, hawthorn Crataegus monogyna, crab apple Malus sylvestris and blackthorn Prunus spinosa are less common. rowan Sorbus aucuparia is restricted to areas with more acid soils. The principal species of the ground vegetation vary with soil type and drainage, but they include dog's mercury Mercurialis perennis, wood anemone Anemone nemorosa and ivy Hedera helix on the alkaline soils, ramsons Allium ursinum on the flushed alkaline slopes, creeping soft grass Holcus mollis on the acid soils of the northern valley and meadowsweet Filipendula ulmaria along the wet valley sides. Species normally restricted to ancient woodlands include herb paris Paris quadrifolia, Solomon's seal Polygonatum multiflorum, lily of the valley Convallaria majalis, toothwort Lathraea squamaria, yellow archangel Lamiastrum galeobdolon and wood melick Melica uniflora. The nationally rare narrow leaved bittercress Cardamine impatiens is of special interest while other species of note include columbine Aquilegia vulgaris, adder's tongue Ophioglossom vulgatum, wild daffodil Narcissus pseudonarcissus, small teasle Dipsacus pilosus, common spotted orchid Dactylorhiza fuchsii, broad leaved helleborine Epipactis helleborine, early purple orchid Orchis mascula, water avens Geum rivale and hybrid avens Geum x intermedium. The widespread occurrence of meadow saffron Colchicum autumnale in woodland is also unusual. The generally sheltered and humid conditions provide an ideal environment for a wide range of lower plants. 114 species of moss, 21 species of liverwort and 122 species of fungi have been recorded. Resident breeding butterflies include the local grizzled skipper Pyrgus malvae, Silver washed fritillary Argynnis paphia and purple hairstreak Favonius quercus. The site supports 41 species of Mollusca. Of particular interest are the nationally rare snails Ena montana and Acicula fusca. Buzzard Buteo buteo, sparrowhawk Accipiter nisus, garden warbler Sylvia borin, spotted flycatcher Muscicapa striata and great spotted woodpecker Dendrocopos major have bred in the woodland in recent years.

Species mentioned