RNAD Broughton Moor Ecological Assessment

RNAD Broughton Moor Ecological Assessment

Introduction

A survey of the ecological habitats present on Broughton Moor RNAD site was carried out on 24th July 1997 by R Jerram and updated following site visits by R Jerram and E Golightly in November and December 2000 and January 2001. A sample survey of buildings for bats was carried out in winter 2000/2001 by Geoff Billington. Additional information on animal groups has been obtained from surveys carried out by members of the Cumbria Wildlife Trust during 1996 and records from previous and subsequent years, the data from which has been compiled by Mr Norman Hammond, a local naturalist.

Ecological Habitats

Semi-improved grassland

This type of grassland covers the majority of the land on the site, it is a formerly agriculturally improved grassland where inputs of fertilisers have ceased, allowing species associated with more natural grassland types to become established amongst the agricultural species. The sward is principally composed of Cynosurus cristatus, Festuca rubra, Agrostis capillaris and Lolium perenne, with frequent Anthoxanthum odoratum and the following herbs: Trifolium repens, Cerastium fontanum, Leontodon autumnalis, Lotus corniculatus, Achillea millefolium, Ranunculus acris, Prunella vulgaris, Bellis perennis, Cirsium arvense, C. vulgare and Euphrasia officinalis agg. In addition to this Campanula rotundifolia, Centaurium erythraea, Trifolium pratense, Hieracium pilosella and Linum catharticum are occasional. Lotus corniculatus can be locally abundant. The bunkers (tall earth embankments around ammunition storage sheds) support a sward with an almost identical species composition, but within which the herbs tend to be more abundant.

Improved grassland

A few fields around the periphery of the site have undergone a greater amount of agricultural improvement than the majority of the grassland. These fields are herb-poor, with swards dominated by Lolium perenne, Cynosurus cristatus and Trifolium repens, with occasional/frequent Cerastium fontanum and Cirsium arvense.

Marshy grassland

Within the semi-improved grassland there are a occasional slight depressions which are damper than the surrounding sward and support a more marshy flora with abundant Juncus inflexus, plus frequent Juncus conglomeratus, J. articulatus, Cynosurus cristatus, Anthoxanthum odoratum, Holcus lanatus, Agrostis stolonifera, Carex panicea, C. demissa, Potentilla anserina and P. erecta. Linum catharticum is occasionally present.

Three areas of marshy grassland differ from the above, one to the north-east of the spoil mound (MG1), one on the northern edge of the site north of Peatmere Hill (MG2) and one between Flamiggs Gill and Horsegrassing Plantation (MG3). The former area (MG1) is dominated by Juncus effusus and Deschampsia cespitosa with abundant/frequent Cirsium arvense, Urtica dioica, Lotus uliginosus, Ranunculus repens, Potentilla anserina, Stellaria alsine, Cirsium palustre and Rumex acetosa.

The northern part of the second area (MG2) is former plantation and is dominated by Deschampsia cespitosa and Juncus effusus, with frequent Cirsium palustre, Epilobium palustre, Vicia cracca, Galium palustre, Rubus fruticosus agg. Dryopteris dilatata, Potentilla erecta, Nardus stricta and Mentha aquatica. The southern part has not been afforested and is dominated by Juncus effusus, plus abundant Galium palustre, Epilobium palustre and locally abundant Molinia caerulea and, very occasionally, Eriophorum angustifolium.

Juncus acutiflorus is abundant in the third area (MG3), with frequent tall herbs, particularly Filipendula ulmaria, Cirsium palustre and Mentha aquatica, plus Ranunculus repens, Carex nigra, Holcus lanatus, Juncus effusus, Juncus inflexus and Deschampsia cespitosa.

Acid grassland

An area of acid grassland is present on the western edge of the site, between Holdens Gill and the site boundary. This is dominated by Agrostis capillaris and Festuca ovina with abundant Potentilla erecta and Lotus corniculatus, and frequent Anthoxanthum odoratum, Holcus lanatus, Achillea ptarmica and Cirsium arvense and occasional Calluna vulgaris. Ulex europaeus is locally abundant, mainly around the margins of the stand.

Broadleaved woodland

Two areas of broadleaved woodland are present, one along Holdens Gill and its tributary Parseys Gill, which is a narrow strip of semi-natural woodland along steep-sided gills. The second, Bottom Wood - Horsegrassing Plantation, also occupies a moderately steep-sided gill along the Bottom Wood section, but Horsegrassing Plantation to the north-east is flat.

Parseys Gill and Holdens Gill south of the old railway track have closed canopies of oak and ash over a well developed understorey of hazel and goat willow. The groundflora is grassy with abundant Deschampsia cespitosa, Brachypodium sylvaticum and Oxalis acetosella, plus frequent/occasional Geranium robertianum, Lonicera periclymenum, Viola riviniana, Primula vulgaris, Potentilla sterilis, Circaea lutetiana, Veronica montana, Polystichum aculeatum, Polypodium vulgare and Dactylis glomerata. North of the old railway the canopy and understory are more open and Scot’s pine becomes frequent in the canopy. The groundflora however remains the same.

Both Bottom Wood and Horsegrassing Plantation are mixed plantations with closed canopies. Bottom Wood has a canopy dominated by sycamore, with frequent ash and Scot’s pine. There is little understorey other than a few scattered hawthorn and hazel bushes. The wood is grazed and has extensive areas of bare soil. Where a groundflora has developed it is generally grassy with abundant Agrostis capillaris, Poa trivialis and Mnium hornum, with occasional to locally frequent Oxalis acetosella, Viola riviniana, Veronica montana, Carex remota, Geranium robertianum, Circaea lutetiana, Deschampsia cespitosa, Brachypodium sylvaticum, Urtica dioica and Potentilla sterilis.

Horsegrassing Plantation has a canopy of Scots pine, ash and oak over a groundflora of Agrostis capillaris, Holcus mollis, Ranunculus repens, Cerastium fontanum and occasional Urtica dioica and Cirsium arvense. Along the stream banks Athyrium filix-femina is present, along with occasional Circaea lutetiana, Oxalis acetosella, Filipendula ulmaria, Deschampsia cespitosa, Lapsana communis and Viola riviniana.

Scrub

A number of areas of scrub are present on the site. Stands of gorse scrub are to be found scattered across the northern half of the site and western gorse is becoming frequent within some areas of felled plantation. These stands tend to be dense, with few other associated species, other than scattered Rubus fruticosus agg. and Holcus lanatus. Isolated gorse bushes are also to be found occasionally on the bunkers.

Mature hawthorn scrub can be found along Flamiggs Gill, together with scattered grey willow, gorse, elder, ash and blackthorn. The canopy is partially open, and there is a grassy groundflora with abundant Agrostis capillaris, Poa trivialis and Holcus mollis, plus Ranunculus repens, Bellis perennis, Brachypodium sylvaticum, Torilis japonica, Prunella vulgaris, Viola riviniana, Filipendula ulmaria, Urtica dioica, Geranium robertianum, Circaea lutetiana and Galium cruciata. The stream banks support Polystichum aculeatum, Dryopteris filix-mas, Elymus caninus, Deschampsia cespitosa, Filipendula ulmaria, Urtica dioica, Angelica sylvestris and Valeriana officinalis.

Willow scrub is present on the southern side of the marshy grassland north of Peatmere Hill. Grey willow is dominant over a groundlayer of Juncus effusus, Galium palustre and Ranunculus repens.

The majority of the old field boundaries present are delineated by hedges. These hedges tend to be dominated by hawthorn, though ash and hazel can be frequent. In general however they are no more than moderately species-rich in terms of shrub and tree species. There appears to have been little or no maintenance of these hedges for many decades and as a result they have become tall and open with little, if any, woodland/hedgerow flora at their bases.

Coniferous plantation

Ribton Wood is a large area of mature Scots pine plantation with occasional oak, ash and goat willow. The groundflora is dominated by the grasses Agrostis capillaris and Holcus mollis, with frequent Oxalis acetosella, Anthoxanthum odoratum and Dactylis glomerata and occasional Brachypodium sylvaticum, Rubus fruticosus agg. and Poa trivialis. Damper areas have frequent Juncus effusus, Carex remota and Cirsium palustre.

The smaller areas of plantation present to the north of Ribton Wood, these have canopies of either pine or spruce. Both types of plantation have similar groundfloras to Ribton Wood, however under the spruce plantations the ground cover is sparser due to the denser shading.

Felled plantation

In the northern half of the site there are extensive areas where stands of coniferous plantation have been felled within the past decade or so. These areas tend to have abundant Deschampsia cespitosa and Digitalis purpurea, with frequent Holcus lanatus, Agrostis capillaris and occasional Rubus fruticosus agg. Juncus conglomeratus, J. effusus, Cirsium arvense, Urtica dioica and Brachypodium sylvaticum. Along Peatmere Hill large stands of western gorse Ulex gallii have developed within felled areas. These are locally dense, and gorse bushes are widely scattered throughout the felled plantations, suggesting that gorse scrub will become more widespread in future.

Open water, swamp and fen

Two ponds are present east of the spoil heap. The western pond has an aquatic flora consisting of Potamogeton natans and Polygonum amphibium with an emergent fringe of Alisma plantago-aquatica, Sparganium erectum, Filipendula ulmaria and Juncus effusus. The eastern half of this pond is dominated by emergent Equisetum palustre with stands of Iris pseudacorus.

The eastern pond is also dominated by emergent Equisetum palustre with stands of Iris pseudacorus, Juncus effusus, Sparganium erectum and occasional Phalaris arundinacea, Lythrum salicaria and Alisma plantago-aquatica.

Both ponds are fringed by grey willows.

The pond on the northern edge of the site on Peatmere Hill supports frequent Potamogeton natans, with a fringe of emergent Juncus effusus and Alisma plantago-aquatica.

The stream/drain that feeds these ponds has an emergent flora of Sparganium erectum, Lythrum salicaria, Phalaris arundinacea, Mentha aquatica, Myosotis scorpioides, Juncus effusus, Glyceria fluitans, Nasturtium officinale and Filipendula ulmaria.

Other vegetation

Spoil

A large steep-sided spoil heap lies in the centre of the site. Most of the sides are unvegetated, other than scattered Festuca ovina and Deschampsia flexuosa, and, on lower slopes stands of common gorse Ulex europaeus. The top has a more developed vegetation with extensive areas of Agrostis capillaris and Festuca ovina grassland with frequent Galium saxatile, Potentilla erecta and Hypochaeris radicata and locally abundant Calluna vulgaris, plus occasional/frequent Trifolium repens, Potentilla erecta, Ulex europaeus, Cerastium fontanum, Cladonia impexa, Hieracium pilosella, Succisa pratense, Deschampsia flexuosa and Lotus corniculatus.

Calcareous grassland

Within Ribton Wood a number of the forestry tracks have been surfaced with limestone chippings. These have been colonised by a number of grassland species, including Carex flacca, Lotus corniculatus, Dactylis glomerata, Holcus lanatus, Deschampsia cespitosa, Agrostis capillaris, Hypochaeris radicata, Leontodon autumnalis, Cerastium fontanum, Prunella vulgaris and Brachypodium sylvaticum. Dactylorhiza fuchsii is abundant in a couple of small areas on the edges of these paths.

Animal records

Birds

Sixty eight species of bird have been recorded breeding on the RNAD site. Of particular importance is the presence of three UK Biodiversity Action Plan (BAP) Priority Species[1], the skylark, grey partridge and song thrush and three British Red Data Book species, the barn owl, curlew, tree sparrow, reed bunting and grey partridge. The Cumbria Biodiversity Action Plan contains Species Action Plans for barn owl and song thrush. Also of note is the use of the buildings on the site for nesting by over 850 pairs of swallow and house martin. Other breeding birds of interest are the tawny owl, little owl, buzzard, kestrel, sparrowhawk, woodcock and heron, though the latter have abandoned the site in recent years following incidents of vandalism.

Mammals

Twenty two mammals have been recorded on the site in recent years, these include three UK BAP Priority Species, the pipistrelle bat, red squirrel and brown hare. A sample survey of buildings on the site in winter 2000/2001 found evidence of bat roosts in one third of the buildings looked at. Red squirrels and all bat species are protected under the Wildlife and Countryside Act 1981. Badgers are also present and these are protected under the Badgers Act 1992. The Cumbria BAP contains Species Action Plans for red squirrel and bats (all Cumbria species).

Reptiles and Amphibians

Three reptiles and four amphibians have been recorded on the site. Of particular note is the presence of great crested newts in five ponds on the site. This species is a UK BAP Priority Species, is protected under the Wildlife and Countryside Act 1981 and has a Cumbria BAP Species Action Plan.

R Jerram 4 10 December 2001

[1] The UK Biodiversity Action Plan aims “To conserve and enhance biological diversity within the UK and to contribute to the conservation of global biodiversity through all appropriate mechanisms”. The UK BAP is a UK Government policy initiative led by the Department of Environment, Food and Rural Affairs. The UK BAP is a series of action plans for species and habitats which are either globally threatened or are rapidly declining in the UK. These are termed priority habitats and species. These action plans outline measures which are needed to conserve these species and habitats.

The Cumbria BAP is part of the delivery of the UK BAP at the local level. It contains action plans for species and habitats which are threatened in Cumbria.