I've not tried using a tree as an antenna, but I have used a tree's roots to augment a ground with very good results. Using stainless steel wood screws and "fender" washers to connect my ground lead at the base of the trunk gave measurable results on my 1200 ft. beverage antenna grounds. 73, J.B., VE3EAR LowFER Beacon "EAR" 188.830 kHz. QRSS30 EN93dr