Too much moss... need more open soil to allow aeration of roots. Also, better for the trunks if moss is not allowed to grow so close and particularly 'up' the trunk [tho I know 'up' is not happening in this situation - yet]. It would be good as well if you can get different mosses to provide variety as one would find on a forest floor.
Rain equals moss and bonsai enthusiasts then remove it as required and put it where it is needed. In nature these trees would not grow such luxuriant moss at their nebari and it looks lush but not natural for the species.
For the continued health of your trees I suggest you scratch a bit away from the trees and reduce a bit of the full surface. Nice looks don't always add up to a healthy setting. But momentarily, after the long dry, the rich green looks marvelous.