Great photos, very inspiring experience.
Croatia is about the size of New Hampshire. Are you telling me that this small country has more great broadleaved trees than the rest of the world together? Or is it that the rest of the world has not yet learned how to find these trees which are there in great numbers.
The species that one can collect here and there are not the same. The climate, the geography and geology are not the same either.
For instance, no sheep where I live, in the UK, you can find trees like Crataegus that have been trimmed by generations of sheep and modelled by the wind.
In France, especially in the southern or central parts of France, there are some conifers and deciduous trees that can be collected... provided it's legal. Scot pines, Olive, etc.
I don't know what the legislation in Croatia is like, but here, it's very strict - and it's a good thing: in Japan, some junipers were so widely collected that the younger "yamadori" are hard to match those that were collected 50 years ago.
I live by the Loire veyy. Up north, miles of wheat, maize and colza fields. South of the Loire, it's still a plain, forests, but it's either private, mind the hunters and the forest guards. If you pick just a handfull of mushrooms, they'll throw it to the ground and step on them, or are in natural parks.
Yes, of course, great trees can be collected anywhere in the world.
But some might find your comments a bit contemptuous.
This was probably not your intention though.