Assart and back again

An evening walk through a less visited wood in the Wye Valley and towards the furthest extremity of this wood, the forestry track cut through a stone wall. A derelict, moss covered stone wall,  surrounded by high oak and beech woodland. My initial thoughts were a simple event chronology of  building of the stone wall, planting of woodland and construction of a forestry track cutting through wall. As that stone walls are rarely constructed through an existing wood and the area of woodland on one side of the wall was carpeted in bluebells and on the other side of the wall, bluebells were colonising through a relict gateway or where the wall had collapsed, which suggested the area enclosed by the wall was once farmland, before reforestation. The light was fading and with exposure duration in seconds and mindful of the return walk to car, only a few images were made.

Derelict stone wall in woodland

Intrigued by the wall in the wood, I consulted a couple of authoritative texts and maps of the area. The general area has some history dating back to Anglo Saxon times,  a Domesday Book entry, Norman manor and the creation of a sizeable family estate in the 16th/17th C, but concentrating on the events pertinent to the stone wall and wood, it is probably best to start in first decade of the 19th C.  In 1803, Admiral Lord Nelson, following a visit to the area, produced a report on the naval timber in the nearby Forest of Dean.  The report included the following statements "These shameful abuses are probably known to those high in power ..." and  "If the Forest of Dean is to be preserved as a useful Forest for the country, strong measures must be pursued. First, the guardian of the support of our Navy must be an intelligent honest man ...". He also wrote that some oak woodlands and fields outwith the statutory Forest of Dean could be purchased to ensure a short and medium term supply of mature timber and planting of oak saplings raised in nurseries for the long term. Following an act of Parliament, replanting of the Forest of Dean commenced between 1808-1818, the events of which didn't go entirely to plan and coincidentally in 1817 the Highmeadow estate of woodland and farmland adjoining the Dean, was purchased by the Crown Commissioners.

Primary and secondary woodland either side of the stone wall

I made a return visit in better light, to make a photographic record of the derelict stone wall, bluebells colonising the secondary woodland and confirm that the wall is the one shown on the modern OS maps against known boundaries and features.

View along the stone wall

A search online produced an illustration of a village map of 1608, that also details the wall enclosing a field and adjacent woodland, the 6":1 Mile late 19th C OS map also show the stone wall traced out in woodland and the modern OS explorer map shows the stone wall, woodland and forestry track. It seems likely that the derelict stone wall was once an estate and/or field boundary on the Highmeadow estate. So what was once woodland, was then assarted for farmland, then reforested in the 1820's and has remained woodland ever since under the management of the then Commissioners of Woods and now by the Forestry Commission.

Former gateway and now entranceway for colonising bluebells

The derelict boundary wall has clearly been an effective barrier to bluebell colonisation, but where breaks occur in the wall there is still a discernible difference in spread and density of flowers, between secondary woodland and the original wood after nearly two centuries.  Another observation would be that lateral colonisation across a slope seems particularly slow, especially against the prevailing wind. I was surprised at how slow the colonisation of former farmland was, especially as bluebells are considered as one of the more 'vigorous' colonisers amongst ancient woodland indicator flora.

Semi natural ancient woodland chanced upon

I had walked by this wood on a fair few occasions over the years, on the track from the Tidenham Chase car park to the Wye Valley woods, but had never set foot in it. The reason being it appeared unpromising, views from the path indicated it to be a modern conifer plantation and I'd never thought to look at it more closely on the ordnance survey map or on google maps satellite view. Recently I was looking for a plantation on ancient woodland site (PAWS) to make a photographic record of any spring woodland flowers present and remembered this wood. The 1:25,000 Ordnance Survey explorer map was scrutinised and it showed symbols for deciduous, evergreen,  coppiced trees, scrub and bracken. The wood had a mixture of boundaries; linear, an indeterminate boundary and the longest boundary was distinctly irregular and adjoining cultivated fields. The adjoining cultivated fields had fairly straight boundaries of planned enclosures, except where the fields bounded the wood on the north side.

1:10,600 surveyed 1880 printed 1887

 A look at the Ordnance Survey 1:10,600 (1 mile = 6 inch)  county map and the wood boundary was extant in 1880 and deciduous trees, firs and brushwood are mapped.

Revision 1900 Published 1903

A check on newer revisions of the 1880 map showed some additional detail in 1900 with woodland rides mapped.

Google satellite view

A Google satellite view shows predominantly deciduous woodland, so my preconceptions of a conifer plantation were way off the mark. The woods place name of Clayton is either a persons name, or Old English for 'clay' and 'town' or 'place with good clay', I thought the persons name more likely as I know Drybrook sandstone outcrops in the core of the Tidenham Chase syncline and is an area undergoing heathland restoration by the Forestry Commission.

BGS Bedrock geology

The BGS geology map shows the wood is underlain by Carboniferous limestones, mudstones and clays with the overlying Drybrook sandstone outcropping just to the south, so the name Clayton Wood seems to be a based on the geology. The geology indicates that the soils might be base rich, which would be a suitable habitat for wildflowers and clay on a north facing slope, would be a good reason to leave the land wooded. My speculation on the woodland and geology had proven to be wide of the mark, so a visit was made.

Clayton Wood - post harvesting operations 

The ground between the heathland on the Drybrook sandstone and Clayton wood was a distinct band of heavy clay, planted with pine and I was thankful for the spell of dry weather.

Singled coppice and wood anemone carpet

Clayton Wood itself was a revelation, recently harvested  of Western Red Cedar/Hemlock and juvenile beech trees the woodland floor was covered in brash and carpets of spring wildflowers.

Wood spurge and Ransoms

 The canopy and understory of the wood are western red cedar/hemlock, beech, oak, hazel coppice, ash, holly, hawthorn, cherry, birch and I suspect some of the suckering coppice stools are small leaved limes that along with some other trees, need to be in leaf for me to make a positively ID.

Dog's Mercury and Primrose

The wildflowers ticked most of the boxes for ancient woodland indicators with carpets of wood anemones, ransoms, dog's mercury, wood spurge and again some other flowers that will need to be in flower to positively identify. I also forget to check if a wood bank defined the boundary, some yellow flowers weren't examined at closer quarters to see if they were celandines or something else and mosses/lichens/rushes/sedges and grasses were overlooked too. I didn't notice any bluebells or patches of nettles, which might be my oversight and I'll check on a future return visit.

I found this an interesting exercise, with desk study and a field visit to establish a woods potential ancient credential and further visits may reveal some more indicators and insights.

Spring woodland flowers and ancient woodland

I am fortunate to live in an area where there is above average, for the UK, coverage of woodland in the the Forest of Dean and Wye Valley and the arrival of spring signals the end to winters dormancy and the emergence of wildflowers. Spring always arrives late in the Forest of Dean woodland due to a colder microclimate, so the woods in the Lower Wye Valley are always the first visited.

Primrose

Many of the local woods have been identified as ancient and woodland historians have employed a number of strategies to identify the lineage of ancient woods i.e tracing their history through medieval records of charters, perambulations, surveys and pipe rolls; maps and place names; estate and tithe accounts; with field archaeology and the presence of outsize coppice stools and veteran pollarded trees also pointing to a woods age and use. Another strategy employed are ecological surveys of ancient woods and secondary woodland, a comparison of species suggests there is a stark difference in flora and fauna found in ancient woodland and that found in secondary woodland. The flora in particular has been classified as indicator species for ancient or semi natural ancient woodland, there are some regional differences, but there are a number of species which are common to all ancient woodland.

Wood anemones

The more indicator species inhabiting a wood, then the more likely that wood is ancient in origin and as some woods have remained under the radar of historical records, then indicator species are important in establishing a convincing case for a woods designation.  The importance of ancient woodland is their high biodiversity and it is apparent from ecological surveys of secondary woodland adjoining an ancient wood, that it takes centuries to create the habitat of an ancient woodland. It is also suspected that some secondary woods isolated from ancient woods, will never naturally evolve into ancient woodland, which emphasises that ancient woodland is an irreplaceable habitat and why ecologists have concentrated their efforts in identifying this special habitat.

Wood Sorrel

Many woods in the Lower Wye Valley have been identified as ancient or semi natural ancient and are afforded legal protection, with responsible organisations managing the woodland for biodiversity and safeguarding the habitat with suitable management plans.

Beech coppice stool 

So, with much anticipation of photographing the ancient woodland and flora, the recent weather has seen; high to strong winds; powder blue skies and bright sunshine. Which translates into blurred flowers, cool blue shadows and harsh lighting, not an ideal scenario for woodland photography or for any landscape photography I can think of, other than picture postcards.

Toothwort

It is still early spring, so hopefully there is still time for the weather to change to more amenable conditions for wild flower and woodland photography.

Ancient woodland

Tŷ Canol Woods

Coed Tŷ Canol is an important ecological site with the twin designation of Special Area of Conservation (SAC) and a National Nature Reserve (NNR).  I could wax lyrical about the trees and rocks cloaked with lichen and moss or the folklore associating the wood with the 'little people', but simple words do not adequately convey the shapes, layers of textures and colour that contribute to the atmosphere of this woodland.

Coed Tŷ Canol

The woodland is predominantly sessile oak with a relatively open canopy allowing sufficient light through for lichens to flourish. More importantly, lichens species appear to grow in specific niche habitats and are slow colonisers, so continuity of that niche habitat is important. The UK has 1,800+ species of lichens and Tŷ Canol has 400+ species, some nationally rare, which is why this relatively small area is a protected landscape. I'm also aware that a lichenologist requires more commitment and dedication, than merely buying a Field Guide and hoping to match a photo with one in the guide, which is why; 1) I struggle miserably to identify and name lichens that I have photographed and 2) I am informed on the habitat niches that lichens occupy.

Lichenscape

In addition to the rich numbers of lichens, the wood has a vibrant moss, liverwort and fern communities, that seemingly carpet every rock, tree and woody debris. The vibrant greenery is a welcome salve for the eyes after the 'dead' winter months of February/March, with straw coloured vegetation on the hills and in my local woods.  As with lichens, these communities also occupy habitat niches too and also indicates that the woodland cover has been continuous for a long time

Coed Tŷ Canol

Moss carpets

Sessile oaks, Polypody ferns, Mosses and Lichens

Coed Tŷ Canol is designated as ancient woodland and many of its flora are indicator species of ancient woodland, it is well worth a visit.

Mynydd Preseli 'Bluestones'

A trip to Pembrokeshire presented the opportunity to revisit the Preseli hills and given the weather forecast a trip to Ty Canol wood would also feature.  Surprisingly the Preseli Hills are poorly represented in UK landscape photography imagery, their remoteness from major population centres and lack of car park views may be contributory factors.  There's a lot that can typred about the Preseli's; The geology and geomorphology are represented in landforms that illustrate a landscape evolving in geological time, plentiful archaeology and folklore, photographically the proximity to the Atlantic usually guarantees some photographic interest in the sky too. Failing all else the Preseli's are a Special Area of Conservation with some rare flora and that flora suggests a macro lens should be taken along.

Mynydd Preseli - April 2010

The Preseli hills have long been associated with the bluestones at Stonehenge, which is at least 135 miles as the crow flies distant and inevitably raises the questions Who, What, Where, When, How and Why, for the presence of bluestones at Stonehenge.  I'd lost touch with recent developments at Stonehenge and the bluestones, so a look at the English Heritage website, recent research papers and blogs brought me up to date with the current consensus on all things Stonehenge. What follows is an overview of recent developments for the bluestones at Stonehenge.

Who decided to use bluestones at Stonehenge is still unknown.

What the bluestones are, is a collective name for any orthostat or debitage at Stonehenge that isn't local to the Salisbury Plain i.e not a Sarsen stone or chalk.  The bluestones are not known to outcrop on or anywhere near to Salisbury Plain and are an assemblage of igneous, volcanic and sedimentary stones.  Geologists have categorised the bluestones (orthostats and debitage) into the following types

Devonian sandstone
Lower Paleozoic sandstone
Volcanic Tuff
Rhyolite
Dolerite

Some of the bluestone types have been further defined into sub groups based on their petrology, which for brevity I've omitted.

There are currently 43 known bluestone orthostats and a considerable spread of bluestone debitage at Stonehenge. The debitage is primarily attributed to human activities in working and destruction of the stones. The actual number of bluestones that once stood at Stonehenge remains unknown, but the consensus is that in the past there were more than 43.

Where the bluestones originated from, is currently the subject of an ongoing investigation by geologists, using petrographic and chemical analysis to correlate bluestone orthostats and debitage at Stonehenge with sampled outcrops in west Wales. This line of investigation has had some success and proved the provenance of some bluestones with a reported high degree of certainty to named outcrops on the Preseli hills and on the northern slope of the Preseli hills in the Afon Neyfer valley. Geologists pinpointed one specific location to an outcrop at Craig Rhos-y-felin and archaeological excavation revealed evidence for quarrying activity of an actual Stonehenge sized bluestone orthostat. However, there are a number of other bluestones that remain unsampled, so their provenance currently remains unknown, if not suspected.  Surprisingly no bluestones are currently provenanced to two of the more prominent landscape features on Mynydd Preseli - Carn Menyn and Foel Drygran. There are also a small number of stones which have no known provenance in the Preseli area viz the largest bluestone at ~6 Tonnes (Altar stone) and its attribution to Lower Devonian sandstone of the Senni formation, places it well outside the Preseli area.

Northern slopes of Mynydd Preseli - October 2011

When the bluestones were first used at Stonehenge is not definitively known, as archaeologists  suspect on the basis of excavation evidence, that some or all of the bluestones have been used in earlier phases of Stonehenge viz Q, R and the Aubrey Holes and in at least one other monument elsewhere in the wider landscape around Stonehenge, viz, the bluestone henge beside the River Avon. The latest date for bluestones incorporation into the present stone arrangement is ~ 2,200 BC.  Archaeologists have good reasons to suspect that bluestones were sited in the Aubrey holes, which have been dated to around 3,000 BC.

How the bluestones arrived at Stonehenge is a cause célèbre and tends to polarise opinions. There's a steady stream of alternative theories involving extra terrestrial aliens, UFO's, magic etc and more conventional theories. The theories tend to reflect modern perceptions and prejudices of Neolithic peoples; inventiveness; skills; technology; intellectual capacity; society; beliefs etc etc. Two of the more conventional theories promoted by Geologists and Archaeologists are; human agency and/or glacial ice.

Glacier terminus and debris

The random assemblage of diverse rock types at Stonehenge would be representative of material quarried over a wide region by glacial ice and subsequently transported. The geology of West Wales has suitably diverse bedrock with igneous, volcanic and sedimentary rocks, spanning from the late Precambrian to the Carboniferous, many of those rock types would be expected to be entrained in glacial ice, flowing across West Wales before finally melting out at the glacier terminus.  Glacial erratics deposited on Salisbury Plain would also conveniently explain their use at Stonehenge, i.e an exotic material and minimal effort needed to move. The theory for glacial ice transport to elsewhere in SW England, would mirror the aforementioned theory, albeit with a nod to increased effort and logistics needed in transporting the glacial bluestone erratics over a greater distance. Disapointingly there is zero geomorphological evidence on Salisbury Plain or elsewhere in the SW England for any other bluestone erratics and no known ingress of Irish Sea Ice across Salisbury plain or indeed large areas of the SW England. Geologists have surveyed and analysed fluvial gravels draining Salisbury Plain and have reported an absence of bluestone erratics, which is a tad worrying as glacial ice can carry a lot of material, from huge boulders to the smallest rock grains. The only known presence of bluestones is in the landscape proximal to Stonehenge.

A seeming absence of evidence for bluestone erratics, even pebble sized erratics in SW England might dampen speculation, alas no, and Brian John, www.brian-mountainman.blogspot.co.uk/ author and prolific blogger on the bluestones and a resident of Pembrokeshire, draws on his own insights and knowledge of glaciers and the Pembrokeshire landscape to promote the transportation of bluestones by glacial ice. A few years ago in Pembrokeshire, I picked up an almost mint condition used copy (never a good sign) in a second hand bookshop of John's vanity publication "The Bluestone Enigma" it made for enteraining reading, for all the wrong reasons. A critical review of John's work and the words; hyperbole; flawed logic, fallacious argument and speculative conjecture would be some of the kinder adjectives used.  I do suspect that the prospect of John's having to 'eat crow' on the glacier transport, will raise the stakes with more snarky comments on disparaging a human agency for bluestone transport and increasingly desperate blog posts on fantastical glacial ice streams.

Why bluestones were preferred by Neolithic people for use in various monument phases at Stonehenge and the surrounding landscape remains unknown. The logistics and effort expended to transport stone from the Preseli area, might imply there was a special significance of the Preseli area in Neolithic peoples psyche.

Mynydd Preseli tors - December 2006

My visit to Mynydd Preseli coincided with a forecast vigorous jet stream and leaden skies, rain and upland gales, so ambitions for a walk and photography were lowered to a short walk around Carn Siân examining the outcrops and I made sure the macro lens was in the rucksack.

Heather and Purple moor grass moorland,  Carn Arthur and a distant Carn Menyn - March 2015

An investigation of the damper bits of moorland revealed a single flower head of Spring Sedge (Carex caryophyllea) Bog Cotton (Eriophorum vaginatum) that was the sum total of floral interest, the novelty of traversing purple moor grass soon wore off and it was time to concentrate on the shelter of rock outcrops.

Eriophorum vaginatum flower head

Some horizontal rock surfaces were relatively free of colonising lichens/moss, a legacy of a recent wildfire perhaps and the phaneritic texture of the dolerite (micro gabbro) was revealed, not quite on the same scale as the the texture of gabbro, but characteristic nonetheless.

Weathered dolerite

Detail phaneritic texture

An interesting moss and lichen community; the lichen Graewe (Stereocaulon evolutum) and Dusky Rock Moss (Andreaea rothii) was growing on one outcrop on Craig Talfynnyd and confirmed the presence of acid rock, possibly volcanic rhyolitic tuffs.

Lichen and Moss on acidic rock outcrop

The remainder of the walk in deteriorating weather provided less inspiring photography opportunities and thoughts turned to the following days excursion to Coed Tŷ Canol.