The Winthrop method

I see a line of dying Wych Elm on a hill.
Well drained by the fractured blocks
Of this contested marl.
A gaping stand of Famine food,
Survivors of even earlier demands
For tight twisted grain,
For good strong rudders, keels, coffins.
For wagon wheels to get behind -
Even the odd water main.
But claimed now by the Dutch disease,
The witless beetles killing the crown
Then further, further down.
There's a lot not right about this picture,
And more, for one tree lies canted -
Awkward against his listing brothers.
Seen from a certain angle, could it be a marker?
The roots below hiding ordnance
In their parched grasp?
You'd need a thran outlook,
And some plausible excuse these days
To go anywhere near it.
This strange ruin located only
By a sleekid eye
An arborist, a terrorist.