The message lgate.org
from "Cal Mac" contains these words:

Could anyone please recommend species of trees which could reach a
height of about 7 meters and which would grow fairly rapidly, in the
Islands of the west of Scotland.The main problem is obviously the wind
which can be strong for days on end in the winter.
Can anything survive this,(I mean trees grow in Siberia).

Winter temperatures in the western isles are very mild, unlike Siberia ;~}

Hawthorn rowan and sycamore can both survive almost anything in west
coast conditions, (where sheep deer and rabbits are fenced out), though
you may find them growing into very windswept shapes. I think hawthorn
suits the windswept look better than the others. You might get them off
to a better start by growing a low shelter belt of something fast and
tough like griselinia, hardy fuchsia, gorse, or even phormium.

Janet.