I love talking about this kind of thing in a meta context, and generally enjoy stories with these kind of details. However I'm also not bothered if the author doesn't mention tree species or whatnot.

Based on what the food we see in the show I would expect Dragon City to be in traditionally rice growing region rather than a traditionally wheat growing region. I wish I knew more about how Chinese cuisine varies by region -- then I might be able to pin point it a further than that. But the foodways do seem Chinese -- so I'd expect a landscape more like Asia than like Europe.

I noticed that there are several globes with Earth shaped continents in Shen Wei's office, so you could make a case for Haixing being an alternate dimension Earth, rather than just some planet somewhere.