Thank you for your interest, Buggy, Paul and Jack. Curiously, I had read that
Zelkova was susceptible to DED, but this may vary depending on the species.
In answer to Paul's request, here are some pictures of the leaves, flowers/nuts, bark and structure of the particular tree they lek on:
There are at least five in the meadow. Here is another, this time embedded in the edge of a copse:
I hope this helps identify the species.
Guy