Jack Painter wrote:
"Overall, there appears to be no effect on the antenna being in fairly
close proximity to many tall trees, and suspended from them."

That was the Signal Corps conclusion for horizontal polarization at HF.
For vertical polarization, surrounding trees are better energy
absorbers. At VHF and UHF, absorption gets worse and worse as frequency
goes up. Too much foliage is impenetrable at VHF and UHF, regardless of
polarization, humidity, ice, snow and wind.

The Signal Corps advises trying horizontal HF antennas among the trees
to avoid detection by the enemy.

Best regards, Richard Harrison, KB5WZI