Girth measurements of trees can generate interesting comparative data, but this becomes even more compelling when the occurrence of ancient and veteran trees is linked with local history. Read on….
There are 3 large Yew (Taxus baccata) trees in the cemetery of the (now) Baptist Church of St John the Baptist in Glyncorrwg (right of centre in photo above). Two of these trees have been classified as veterans by the Ancient Yew Group. As a guideline, a Yew tree with a girth (measured at a height of 1.5 metres = 5 feet) between 4.9 metres and 7.0 metres is classified as a veteran. Anything bigger than that is regarded as an ancient tree. The largest of the 3 Glyncorrwg trees had its girth (circumference) at a height of 1.5 metres measured as 6.63 metres in 1998. A measurements made today, i.e. 15 years later, was 6.73 metres, which is very close to the 1998 figure.
However, as noted by the Ancient Yew Group, this tree has split into two trunks and this makes comparative measurements problematic.
The individual trunks are about 4.0 metres in girth and the bole below the split is more than 6.0 metres in girth. Clearly, this is a big tree, which can be categorised as veteran. This means that it is probably older than 500 years and less than 1,200 years old. Comparing exact measurements within categories is fairly meaningless because the errors and confidence limits associated with the relationship between girth measurements and tree age are very large. But, placing trees in categories is important. The Ancient Yew Group gives expert guidance for this.
The other 2 Glyncorrwg trees are smaller, (measurements today - 3.68 metres and 3.85 metres), but one of them has a significant portion of its trunk missing. All 3 trees are surrounded at their bases by their own stone retaining wall, which appear to have been added (or restored) in recent times. Consequently, the lower portions of the boles of the trees seem to be buried in soil.
The earliest record that I can find of the Glyncorrwg Yews is from a document written by Nicholas Carlisle in 1811, who wrote ‘In the Church-yard of Glyncorwg (sic) , are five remarkable Yew Trees, the largest of which (in 1810) measures 10 yards 4 inches in circumference.’ There are a number of interesting things here. Firstly, we have the date, which is more than 200 years ago. Secondly the girth of the largest tree (given as 30 feet) is just over 9 metres. Such a tree would be categorized as ancient, i.e. over 800 years old and probably over 1,000 years old, or more. Thirdly, there were 5 trees! In other words, 2 have gone and it looks as if one of them was already an ancient specimen 200 years ago. Interestingly this tree was recorded as ‘still there’ in 1933 by Hyde and Harrison (Welsh Timber Trees, 1977), so there may be someone in Glyncorrwg who can remember it.
So how does this match up with local history? The church in Glyncorrwg cemetery (St John the Baptist) appears to have a long pre-reformation history. Although most of the church as it stands now is about 100 years old, it also has a medieval history. The current building, rebuilt in 1907, has the original east window, holy water stoup and font derived from the earlier church, estimated to be about 600 years old. In fact some evidence links the original church with the Cistercian Abbey at Margam. All this is consistent with the occurrence of veteran trees that are still there. But what about that ancient tree? Perhaps it was planted by the monks in the 12th century, but, perhaps it was even older than that. Could it have been planted by Celtic Christians? The church’s web site (www.parishofglyncorrwg.co.uk/) suggests that the structure and location of the cemetery indicate a Celtic origin. Fascinating stuff!