May 2020: The Allerston Ash

Julian Forbes-Laird writes…

Another ancient tree find, this time on the North Yorkshire Moors. This ash tree is very difficult to date as its vestigial stem sections have collapsed into each other, preventing accurate measurement, plus there is so much of the original stem missing. Complicating matters further is a long period of senescence during which the tree will have been making minimal increment.

So how old is it?

After much head-scratching, a plausible reconstruction of the intact stem suggests a peak size of ca. 2.7m diameter. To assist in understanding how large it is, when I first saw it there were three sheep sheltering inside the hollow, and several others could have fitted in too!

So, allowing for a century of minimal increment (surely a conservative estimate), I would tentatively place this tree within the range 850-950 years old, the latter being around the time of the Norman Conquest and the Viking settlement of Greenland (Grunland).

However, the tree’s exposed location in an area known for long, hard winters suggests slower than average growth, so it could be much older.