A planting invoice from 1961, a county master chronology that every other wood in the district agrees with, and thirty-eight trees that have all had more growing seasons than there have been years.
I am a volunteer with a woodland trust and the part of the job I actually care about is dating trees.
Not guessing at them. Dating them, with a number and a margin, so a compartment can be managed properly.
I want to explain how that is done, because all of this rests on it and most people have the wrong idea.
You take a core. The tool is an increment borer, a hollow steel auger about five millimetres across that you screw into the trunk at chest height and withdraw with a little spoon of wood in it, a pencil of timber from bark to pith.
The tree does not mind. It is a smaller wound than a woodpecker makes and it closes over.
Then you mount it, sand it, and count under a lens. One ring is one growing season: a pale band of fast spring wood and a dark band of dense late wood, and the boundary between one year's late wood and the next year's early wood is sharp enough to put a needle on.
And then you cross-date, which is the step everybody skips when they tell you how old a tree is.
Cross-dating is the whole discipline.
Counting tells you how many seasons the tree has grown. It does not tell you which calendar years those were, because rings can be missing, a bad year can be too thin to register, and an injury can lay down a false boundary inside a single summer.
So you do not trust the count. You match the pattern.
Every wood in a district shares its weather, and weather writes the same signature into every tree in it. A drought year is narrow in everything. A warm wet year is wide. The sequence of wide and narrow is a barcode, and it is the same barcode across a whole county.
The marker years here are well known and I did not invent them. 1976 is the big one, the drought, and in this part of the country it is so narrow you will miss it if you are careless. 1995 is narrow. 2018 is narrow. 1947 is wide and unmistakable.
You lay your core against the master chronology for the region, match the barcode, and the calendar falls into place. If it matches, you are right. If it does not, you are wrong, and the honest thing is to say so and go and find your error.
Compartment 4 is eleven acres of mixed plantation on the north side of the wood.
We have the planting record for it, because the trust holds the estate papers. Compartment 4 went in during the spring of 1961, oak with a beech nurse, and there is an invoice for the stock and a handwritten note of the work, and two of the men who did it were alive when I started.
So the innermost rings in there are 1961, and in the spring of 2026 a tree from that planting carries sixty-five rings, and the margin on that is nothing at all, because for once we are not estimating. We have the receipt.
I cored nine trees in Compartment 4 in the autumn of 2019.
Every one of them had a ring too many.
I assumed false rings. That is the ordinary answer and it is usually the right one. A late frost or a defoliation can make a tree shut down and restart inside one summer, and the extra boundary looks like a year that never happened.
A false ring has a tell. The late wood of a false boundary is not as dark or as abrupt as a true one, and with a good lens and the light right you can watch it fade instead of stop.
I looked at all nine, and then I took them to a man at a university who does this properly and who gave me an afternoon because I had brought him good cores.
He said they were not false rings. He said every boundary on all nine was a true annual boundary and that he would put that in writing.
Then he cross-dated them for me, which is what I had actually gone for.
They match. All nine match the county master chronology for this district, ring for ring, with a correlation he called unusually good for plantation oak.
1976 is in there, narrow. 1995 is in there. 2018 is in there, and it is the fourth ring in from the bark.
The fourth. In a core taken in 2019 it should be the second.
So the barcode says one thing and the count says another, in a tree we have the invoice for.
I have to be precise about what that means, because it is not a small thing and I have had years to find a way for it to be a small thing.
It means the pattern of the seasons in those trees agrees exactly with the pattern of the seasons in the rest of the county, and that there are extra seasons in with them that the rest of the county did not have.
They are not all at the end. They are not all in one place. Across the nine cores there are between one and three rings that sit between two correctly dated rings and have nothing in the master chronology to be.
They do not look strange. They are ordinary years. Mid-width, clean boundaries, the ring of a tree that had an unremarkable summer.
I have cored thirty-eight trees in Compartment 4 over six years now, which is more than I should have and which I have justified to myself in several ways.
Thirty-eight out of thirty-eight are over-count.
I have also cored twenty-two trees in Compartments 1, 2, 3, 5 and 6, which are the same wood, the same slope, a hundred metres off, several of them from the same 1961 planting.
Twenty-two out of twenty-two are right. Correct count, cross-dating clean, nothing extra.
The boundary between Compartment 4 and Compartment 3 is a ride, a grass track about four metres wide that the planting gangs left for access.
I have cored the four nearest trees on each side of it. The Compartment 4 side is over by one. The Compartment 3 side is right.
The thing I have not told the man at the university.
In the spring of 2024 I went back to three of the 2019 trees, the same three, and took a second core a hand's breadth round the trunk from the first.
Five growing seasons had passed between the two corings.
The new cores have seven more rings than the old ones.
Two extra, laid down in five years, in the outer wood, in trees I have photographs of, in a compartment I can walk to in nine minutes from the car park.
And they cross-date. 2022 is in there where it belongs. 2018 is in there. The extras are in between, and they are ordinary, and there are more of them than there used to be.
I am sixty-one and I have a spreadsheet with eighty-two cores in it and a master chronology I did not build and cannot argue with.
What I do with it, in practice, is nothing. I file the survey for Compartments 1 to 3 and 5 to 6, which is honest work, and I write Compartment 4 up as requiring further investigation, which is a phrase that can sit in a file for twenty years.
Because the only sentence I have that fits all eighty-two cores is that Compartment 4 has had more summers in it than the calendar has had, and that whatever is counting them is not slowing down.
I still go in there. It is a nice wood. The trees are sixty-five years old and they have seventy-one rings in them and they do not look any different from the ones that do not.