I recall comments at a hamfest talk several years ago from Roy, W7EL, that his two-element 40m vertical array appeared to have an unintended null in the direction of a stand of evergreen trees not too far away from his antenna system. While this is two octaves above 160m, it at least indicates the possibility of absorption problems. In all likelihood, different tree species at different times of year could introduce a lot of variability.
That was a rather dense stand of trees.
A few trees a reasonable distance from a LF antenna are not going to do anything observable. A single tree at 2 GHz can mean 20-40 dB. It has nothing to do with resonance, but rather how much the electric field is killed by the resistors sticking up in the air.
_______________________________________________ Stew Perry Topband Distance Challenge coming on December 29th.
