It took me a while to spot your problem, but you mean the boxes the appear around the trees.
That is because you have used 'billboard' style (flat) trees.
I don't do a lot of renders but using 'physical' render settings should help.
I found this post that might help you out.
https://archicad-talk.graphisoft.com/viewtopic.php?f=3&t=54709
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11