Mike--I did a presentation on moss for a local bonsai club and did some research in a college botany text for the presentation. In the section on moss and other bryophytes, it mentioned there has been observed an association between moss and mycorrhizae. I have noticed an increase of surface roots directly below moss I have grown with bonsai when I lift it to re-pot the tree. It definitely has a positive effect on my trees and I place moss on the soil surface around the trunk of a newly collected tree to encourage the growth of fine feeder roots close to the surface and near the trunk of the tree--just where you want them
