Would it not be the case then, under centripetal force those trees should be angled?
if you assume, they are grown there and not only planted after grown somewhere else.
but because they reoccur in the same height and same numbers, i'm very positive that there is a waterworld somewhere, with a small island, where they are grown, and then brought to those stations all over the bubble. those waterworld is a contractor of the famous architect, who builds those station interieurs in human space. he originally got famous in the empire, but now everywhere goverments want to have such an interieur!