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...any reason why they can't be Italian Alder?
The cones look quite "long" and barrel-shaped, so they could easily be A. cordata.
Although as you describe them as growing in abundance, they are more likely to be the common Alder: but still, I'd be interested to hear any reasoning, for or against.
Or pictures of the leaf-litter, that would be helpful...!
How to take close-ups with cheap phone and hand-lens:
Field Guides for Budding Botanists:
Stace says of A. cordata "female flower groups 1-3 on a common stalk".
Having 3-8 is good for the rest.
...how do you define the common stalk?
If you allow the common stalk to be branched, then I am seeing no more than 3 catkins on each stalk in the photos above.
And a quick trawl of google images gives me nothing that I would call definite - both incana and glutinosa appear to have "bunches" of three catkins. I haven't yet seen any A.incana photos with more than 3 catkins per stalk.
The plot thickens...
Cones! Not catkins!!
A. cordata - not incana!
Sorry - research continues...
Lat/Lng: 51.3, -1.2
OS grid ref: SU5965