Hi, the full Effect is stored in Max parameters of the Forest object. Theorically it would be possible to copy these parameters from one object to other using Maxscript, and replicate the Effect.
But really this is something we never tried, i'm not sure if that will work.
These are all the parameters. Please note that several of them are arrays:
"effects", "efenable", "pf_efonlyrender", "efpaid", "efpatype", "efpaname", "efpalimit", "efpadesc", "efpanumtype", "efpaintval", "efpaintmin","efpaintmax", "efpaintdef", "efpafloatval", "efpafloatmin", "efpafloatmax", "efpafloatdef", "efpaunitval", "efpaunitmin","efpaunitmax", "efpaunitdef", "efpainode", "efpacontref", "efpacontanim", "efpacontype"