Someone has planted different trees on my maps.....I always seem to get killed when I get too close... anyway, I don't like flying that low habitually and your foe have to come up sometime so keep altitude, spot them and kill em!......
You wan't to stop people flying low just set the game with poor weather and and let the tree dwellers spend the entire match lopping trees while the true flyers compete at altitude using cloud cover as the correct means of hiding..........