I am allergic to most everything. On the 0 to 4 scale, 4 being the most severe reaction, I reacted a 4 to trees. I reacted a 3 to pollen, dust, indoor mold and outdoor mold. This is not pleasant. I have included a satellite photo of my neighborhood for emphasis. The red circle is my house, the Green circled area is swamp, the blue circled areas are woods.
The tiny section of road seen in the upper left corner is a 4-lane highway. I can barely hear it at night thanks to all these trees. Woods are a mixed blessing for me.