old oak tree
I think a neighbor is poisoning trees in our subdivision park, making the subdivision pay for it to be cut down so he can use them for firewood. What makes me suspicious is the way the trees die back. I personally can't find drilled holes or copper nails, etc. that indicate it was poisoned. But they will have green leaves that suddenly wither (still green, don't turn black or brown). The withering starts at the top and works its way down the tree - the top leaves look green but crunchy and lower leaves are normal. It works its way down the tree in this manner. This happens in the fall and he says "guess it didn't survive the winter" the following spring. But (I personally think) the trees never get the chance to even turn brown or fall off (some leaves will still be green but dried up stuck to the branches the following spring but the tree is dead.(I sorta find that entertaining, because I think, he should at least wait till it loses fall leaves for it to be convincing). Anyhow, does it sound like he is killing the trees to you or is there actually a disease I am unaware of that will do this? The trees will start to "look odd" for about a month before it effects all the leaves. And if he is doing this, can you maybe tell he how he is doing it so secretly.(he has his own trees that will make good firewood too).
Trees can suffer many different types of disease or insect damage.
You many want to see if your local Park and Recreation Board will have the tree inspected by a profession. This is best way to identify the cause of the the mature trees stress.
Here are some links with more information.