[TowerTalk] Tree attenuation

[Jim Lux]

At 04:45 PM 11/7/2005, Cqtestk4xs at aol.com wrote:
>Everything I have observed is trees make very little
>difference at lower HF. My last house had vertical antennas
>nestled in trees, and everything appeared to work as well as
>any other stations in pileups. I can't imagine a horizontal
>antenna being worse...........de W8JI
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>I would imagine there might be more of an effect with "juicy" trees, than
>with dryer trees.  Along this line of thinking, you might get a break in the
>winter when operating in a forest of deciduous trees rather than 
>coniferous trees,
>since the deciduous are not carrying as much water with various minerals in
>the winter.  There may be a very small attenuation with the trees.  Just a
>thought.
>
>Bill  K4XS

That's actually been quantified, at least for the VHF and up frequencies.. 
The U Texas report has a whole part of chapter 2 that discusses the effects 
of foliage presence and seasonal variations.