Seems like all the leafs on beech trees are turning brown in CT. Some sort of disease going around. It will be interesting to see if they rebound or will become extinct in the northeast like ash trees have.
The solution is sadly cut and squirt with low concentration triclopyr (garlon) Penn state has a bulletin on it. On small trees they are completely cut while on the bigger ones, the tree is either girdled first or there is ax cut every 3" of the circumference then the herbicide is applied to the wound. Triclopyr at low concentration stays in the root system its applied to and doesnt spread into the soil while Roundup tends to kill everything. It breaks down quick. It need to be mixed and diluted with diesel before application. Sadly most of my beech is not readily accessible so it will rot in the woods.