Bold Moss, 22 May 2010            Leader Peter Gateley

Thirteen members gathered at St Helens Junction station for the walk north-east onto the former Bold Colliery tip, now known as Colliers Moss Common.  We started off by looking at grasses in the station car park where Red Fescue (Festuca rubra), Rough-stalked Meadowgrass  (Poa trivialis), Sterile Brome (Anisantha sterilis), Soft Brome (Bromus hordeaceus)and Cocksfoot (Dactylis glomerata) were all just coming into flower, also in flower were several good plants of Field Madder (Sherardia arvensis), along the edges of the exotic shrub beds.  We left the station on the path along the base of a high retaining wall with a suite of both native and alien plants growing from the mortar, including Thale Cress (Arabidopsis thaliana), Coltsfoot (Tussilago farfara), Wall Speedwell (Veronica arvensis), Buddleia (Buddleja davidii), Box-leaved honeysuckle (Lonicera pileata) and Oxford Ragwort (Senecio squalidus).

 

We entered the site via Hoghton Road looking at various typical urban ruderal species and plantings along the way.  The path took us through quite species-rich grassland with much Knapweed (Centaurea nigra) and Meadow Buttercup (Ranunculus acris) but also abundant birds-foot trefoil, but the continental variety (Lotus corniculatus var. sativus) that grows tall and leggy rather than the native ground-hugging form, indicating that the sides of the path had been seeded with a ‘wildflower’ seed mix.  We later saw some colonies of the native type in good flower.

 

The many plantings carried out to restore the colliery waste have matured greatly over the last few decades.  The oldest plantings were carried out by the National Coal Board in the early 1970s to present a green face to the bare grey tip edge for passengers on the Liverpool Manchester Railway.  We looked at and compared the nitrogen-fixing species planted into the low nutrient spoil, four main tree species of which only Alder (Alnus glutinosa) is native; the others are Italian Alder (A. cordata) , Grey Alder (A. incana) and False-acacia (Robinia pseudoacacia).  Later the Groundwork Trust supplemented this plantation with natives such as Oak (Quercus robur), also birches and willows seeded themselves adding to the rather more natural look of this southern face of the former tip.

 

As well as colliery waste from the former Bold Colliery some parts of the tip also received pulverised fuel ash (PFA) from the adjacent Bold Power Station (both demolished years ago).  The PFA had a mollifying effect on the very acidic coal waste and allowed more rapid natural regeneration of birch and willow scrub, much of which has now progressed to woodland.  The colliery waste was tipped into an area of cut-over lowland raised mire beyond which the surrounding land was either heavily industrialised and urbanised or intensively farmed there was no existing old woodland nearby to provide propagules for the full range of woodland species.  The birch and willow seeds blew in on the wind, as did fern and moss spores, birds later delivered berry-bearing species such as hawthorn, bramble, elder, honeysuckle etc and jays brought in acorns.  However there was almost no development of groundflora, so in the 1980s experimental blocks of bluebell (Hyacinthoides non-scripta), Wood Sage (Teucrium scorodonia), Hedge Bedstraw (Galium album) and Primrose (Primula vulgaris) were planted under the developing canopy and monitored under the auspices of Liverpool University.  Although the monitoring was discontinued once the PhD student graduated, the plants have continued to grow well beyond their original bounds and make a great contribution to the natural feel of the woodland on this artificial site.  Near to these plantings a colony of Adders-tongue (Ophioglossum vulgatum) was spotted by a sharp-eyed member.

From the eastern side of the former tip the long drought made it possible for a brief foray into the Purple Moor-grass (Molinia caerulra) dominated cut-over surface of Burtonwood Moss, part of the once large mire whose turbary rights were shared amongst four surrounding townships.  Fragments of Bold Moss and Sutton Moss survive around the tip edge but Parr Moss was almost totally buried and nothing now remains.  Burtonwood Moss is the largest surviving fragment and previous management to retain water in the system has been effective, the bunds across the drains allowing re-wetting of the peat and development of large Sphagnum hummocks.  On Burtonwood Moss we noted a colony of Marsh Pennywort (Hydrocotyle vulgaris) in a damp hollow and much Tormentil (Potentilla erecta) on drier areas, another colony of adders-tongue was also noted amongst the (burnt-over) Molinia tussocks.

Around the northern edge of the former tip, the large utilitarian drain that was dug along its edge has been re-shaped and formed into a series of wetlands linked by a gently meandering watercourse, a wide range of water and water’s-edge plants was noted here, contrasting with the generally dry and acidic nature of much of the site. 

Also on parts of the northern and north-western slopes areas of heathland have been developed amongst the plantations and naturally regenerated woodlands.  Much Heather (Calluna vulgaris) was noted, some of this naturally spread from the surviving mire edges but the largest blocks derive from introduction of heather seed by the Groundwork Trust.  The surface of the colliery waste in these areas had such high levels of acidity that Prof. Tony Bradshaw recommended that liming would be required to raise the pH to a level that would more suit the heather.  To this end a crusher was employed to grind concrete demolition waste into suitable sized particles to spread over and incorporate into the tip surface, the result is now some fine areas of natural-looking heath development.

On their way back from the northern edge the party was now getting severely overheated under the relentless sun and very high temperatures, so we only had a cursory glance at the former settling lagoons, once bare and grey but now supporting extensive reedbed (Phragmites australis) with peripheral clumps of Common Cotton-grass (Eriophorum angustifolium), just coming into its fluffy seed stage.  Before we got back to the station the majority of the group had diverted to the Junction Inn for a cooling drink and when we got back to our car the temperature reading was 32 degrees!

Adders-tonge in Molinia	central lagoon reedbeds	Cotton-grass	Grey Alderl	Grey Willow & Goat Willow

groundflora planting	heath scrub mosaic	Italian Alder	lunch by the millenium bridgel	negotiating the dried ditch

northern wetland fringe	Primroses	spread of Primroses