Tuesday 18 October 2011

A Dendrochronology Adventure


As well as its many other useful community roles Archaeology Scotland fulfils Jonathan Wordsworth (Rural Land use Adviser) has also been doing a bit of tree dating for people. On Friday the 7th I went along to give him a hand. So armed with a rucksack full of mysterious rods from the Forestry Commission we set of to a house near Selkirk to drill small holes in trees. The trees we were dating were Sycamores growing over a dry stone structure in a garden. It was hoped that by establishing the age of the trees a terminus ante quem could be gained for the building beneath. Jonathan being experienced in this type of thing had bribed the met office arranging a fantastic sunny day with only a little wind, a useful tip for me after Ardoch.

Jonathan recording

Taking Dendro samples is a bit like taking an archaeological soil sample. So the tree gets a recording sheet (like a contest sheet) with all its vital statistics (height, girth etc.) so lots of measuring and photographing and each drinking straw is labelled ready for it’s core. Taking the samples however is rather different to at an archaeological site were you just put some soil in a bag. The first thing that strikes you about the corer is that it is very thin and the main worry when you start is that you might break it. However the main problem seems to be it getting stuck in the tree as the wait of it pushing down does make it quite difficult to twist out.


Taking a sample



If there is a rotten core in the tree the thread on the corer has nothing to grip and it can be impossible to get out, a big problem on old trees and as might be imagined it makes it had to age to. Luckily though we managed to retrieve the corer each time and get 4 good samples from 3 trees. There is still plenty of work to be done and once the cores have dried out I will hopefully be helping Jonathan in the lab. 





                                                       
One of the cores fresh from the tree


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