Hello,

Thanks for adding more information about trees.

A bit of a warning: "wikidata" or "wikipedia" links are to be used exclusively if there is a corresponding entry about the object itself.

For instance, if there is a particularly remarkable tree that has its own wikipedia entry, then it is eligible.  (This is very rare, apparently there are only 3 such objects in Belgium, here is one of them: https://nl.wikipedia.org/wiki/Linde_van_Conjoux)

For most trees, you should definitely not associate them through those tags.

You can use "species.wikidata" for this.

Some useful documentation here: https://wiki.openstreetmap.org/wiki/Key:species:wikidata