Chestnut Article
This is a rough Copy of an article I wrote for the Quarterly Journal of Forestry. The article actually contains more Photos.
If the Romans Did Not Bring Sweet Chestnut to Britain, Who Did? John Pitcairn looks into this intriguing question following a throwaway remark at the 2023 Whole Society Meeting.
At the recent excellent Whole Society Meeting hosted by the South Eastern Division, we saw exemplary sweet chestnut coppice silviculture and were introduced to its economic and cultural importance. At one estate the host, in an almost throwaway remark, said that a Dr Robin Jarman had made a convincing case for the Romans not being responsible for the introduction of sweet chestnut into Britain and that the first evidence for it was from the 6th or 7th century. This, according to my schoolboy history, was when the Jutes, Angles and Saxons arrived from Denmark and northern continental Europe. These are not areas I associate with sweet chestnut, and a Roman introduction seemed more likely to me. I realised I had no idea what evidence there might be and decided to do some research online. It was an interesting idea to explore and focussing on papers that were freely available I quickly located and downloaded a thesis ‘Sweet chestnut (Castanea sativa Mill.) in Britain: a multi-proxy approach to determine its origins and cultural significance’ by Robin Andrew Jarman (Jarman, 2019). I did read all 57 pages of text but not necessarily the seven pages of references! I thought readers might appreciate a summary of what I discovered.
Fortunately, the introduction did explain the importance of determining the date of sweet chestnut’s arrival, which I thought interesting but unimportant. Whether sweet chestnut is indigenous, an archaeophyte (an ancient introduction) or a neophyte (a modern one) is a significant question. The question relates to its naturalness, a key function in the Nature Conservation Review 1977 which determines which species should be protected or regarded as invasive; this might become relevant should sweet chestnut blight take hold in this country.
The aim of the thesis was to determine:
When is the earliest verified date for sweet chestnut growing in Britain?
Whence do the longest-established British sweet chestnut trees derive?
Does new evidence for antiquity and origins alter the ecological and cultural significance of sweet chestnut in Britain?
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| King’s Wood near Worksop, Sherwood Forest, Sweet Chestnut originally planted by the Dukes of Portland. |
I shall just cover the parts relevant to sweet chestnut’s arrival and any information as to where it may have come from, considering what the evidence is and why Dr Jarman cast doubt on it. The debate on the origin of British sweet chestnut has a long history. John Evelyn considered it non-native and in his 1706 4th edition of Silva suggested a Roman introduction. This became the consensus view of the Royal Society in the 18th century but lacked evidence. Oliver Rackham believed sweet chestnut to be a Roman import, or so I thought. Dr Jarman reveals he worked with Rackham on and off from 1971, and that Rackham had reservations about the species being a Roman introduction. The idea was being quoted and requoted in an academic echo chamber without the primary evidence being checked. It became a ‘factoid’ as Rackham called it (something everyone believes but is not, in fact, true). As I am taking what Dr Jarman has written at face value, I may be contributing to a new ‘factoid’! Dr Jarman has tried to re-examine original archaeological material and interview the researchers. He also visited semi-natural woodlands as well as ancient chestnut trees both alive and dead, to establish its cultural and social significance. A literature review was undertaken, and archaeological archives were reviewed looking for pollen, charcoal, nuts, and timber references prior to 1350 AD. An attempt was made to locate all recorded archived specimens up to 650 AD and to re-evaluate their authenticity with modern techniques. This was carried out in partnership with English Heritage. The thesis was essentially a summary of a number of previously published papers that Dr Jarman had been involved with, usually as lead author. The thesis is divided into four sections: (1) archaeological records, (2) dendrochronology, (3) genetics, and (4) historical ecology. What follows is my understanding of the key points Dr Jarman makes grouped into ‘archaeological records’ and then a combination of the last three sections of his thesis.
Archaeological records.
Dr Jarman located 35 archaeological records of archived sweet chestnut material from before 650 AD, i.e. the Roman and post-Roman period. He tried to find and re-examine them physically. For me, the most striking finding was that there were no confirmed records of sweet chestnut pollen prior to 650 AD. There were only two reports of archaeological records of sweet chestnut nut fragments in the pre-medieval period. One was from an excavation at Great Holts Farm in Essex in the 1990s. The find consisted of five fragments of chestnut pericarp found in a Roman well that had been filled with rubble and rubbish. The waterlogged bottom of the well contained organic material including “a few fragments of sweet chestnut nut pericarps, walnuts, hazelnuts, olive stones, grape pips, stone pine nuts, cherry stones, sloe, bullace and apple pips.” Some of these items must have been imported, for what looks like feasting. This cannot be considered good evidence for a local source of chestnuts, not that it had been claimed to be. The other reported sample, from Castle Street in Carlisle, was radiocarbon dated to a much later period. Reports of the sweet chestnut charcoal remains also proved problematic, in part because many of the recorded archived pieces could not be located. There was also a degree of misidentification. Samples recorded as sweet chestnut turned out to be ash or alder, but mainly oak. Small pieces, particularly small branch wood, may be indistinguishable from oak. Oak can confidently be distinguished from sweet chestnut by the presence of multiseriate medullary rays. The problem is that the absence of rays particularly in a small fragment is not proof it is chestnut. Creating fresh surfaces for examination was not possible due to the importance of the specimens. The dating of some samples could not be verified or was confirmed to be inaccurate. Some key samples were from 19th century excavations and their accounts had been regularly requoted but had not been questioned. Reported wood and wooden artefacts were confirmed; however, a writing tablet or a tool handle could easily have been imported. There are waterlogged chestnut stakes and piles from the Alverstone Marshes on the Isle of Wight, which have been carbon dated to the 6th and 9th-10th century, but this study had not been published when Dr Jarman put his thesis together in 2019. There is a possible sweet chestnut pollen grain from Uckington, Gloucestershire that is dated to the 7th century. This with the Alvestone Marshes wood could be the only physical evidence of sweet chestnut products that could have been derived from plantations established in the Roman period. In summary, no definitive archived material could be found to confirm locally grown sweet chestnut in England and Wales during the Roman and immediate post-Roman period.
Sweet chestnut regenerates freely.
Historical ecology/genetics/
dendrochronology.
The earliest written record for growing sweet chestnut is in the 12th century (1113 AD), from legal ecclesiastic documents near the current Forest of Dean. It must, therefore, have been established in the 11th century at the latest. There are a number of large ancient sweet chestnut trees on estates and in former deer parks, some shown to be more than 400 years old. Dendrochronology does not take any sweet chestnut back more than a few hundred years; DNA analysis has confirmed ancient clonal coppice stools but provides no date. DNA might provide evidence for where introduced sweet chestnut originated and so provide clues to who introduced it. DNA analysis has been carried out on British and Irish sweet chestnut for comparison with European records. Sweet chestnut along with other flora retreated to refugia ahead of the ice sheets of the Ice Ages.
Three refugia genepools have been identified. An eastern (E. Turkey and the Caucasus), a central (W. Turkey, Greece and part of the Balkans), and a western (Italy, Spain, Portugal and southern parts of France and Switzerland). DNA samples from England and Wales are from the western area but they represent two separate genepools. These genepools are geographically mixed, suggesting at least two substantial introductions. The older British DNA samples showed some commonality with samples from Portugal to Romania. It is a diverse genepool but whether that is because of multiple introductions or because of mixing on the continent prior to introduction cannot currently be determined. Ancient parkland trees usually came from NW Iberia while plantations <200 years old were more likely to be Italian; one can imagine members of the gentry returning from their grand tour with pockets full of chestnuts! Sweet chestnut does not inform British myth or legend but is often planted in parks or gardens in significant places. It is of considerable economic and practical importance. One of the reasons for calling sweet chestnut an ‘honorary native’ is that it forms ecological associations within semi-natural woodlands, which have been stable for hundreds of years. They are also similar to forest vegetation associations on the continent. My initial reaction to the lack of pollen evidence may have been misplaced. British sweet chestnut pollen samples are very rare from the whole medieval period, Sweet chestnut produces viable seed and naturally regenerates. “If the Romans made a concerted effort to introduce sweet chestnut, there is evidence they failed!”
