This is purely a stylistic choice, but I feel like having every leaf explicitly individually detailed is really over-doing it. It looks great as a standalone piece, but as what is effectively background art, it's maybe too strong.
Something about the lines in the trunk feel a bit 'pinched', too. It's made up of three individual cylindrical shapes, and the one on the left is over-powering the one in the middle, which should be the real core of the trunk. In a one-off, individual piece, again, it would probably be fine to make the tree look imperfect as normal trees usually are. The fact that you're leaning to slightly cartoon-y means (in my mind) that you can only delve in to "imperfect" so far, because cartoons kind of deal in that iconic look of things.
If that makes any sense at all.
Beautifully colored, however, and a real treat to look at.