Looks like some kind of canker disease, maybe "Eutypella parasitica". I don't think you can save that tree. This post was edited by Huggorm on Sun, May 4, 14 at 11:35

One of my maple's appears to be dying. Can anyone tell me what's going on with it? It had full leaf coverage this summer but over the last few weeks the leaves have started turning brown and dry. I also noticed these white spots all over the bark. This is right in front of my house and I would really like to save it if possible as well as keep my other maples from getting it. Any suggestions/information would be appreciated. Image link:

Could have been caused by a variety of things, at an early age even. I highly doubt that it was caused recently by lightning or recently at all. Could've been guy wire damaged to the trunk at an early age. Wounds can be an avenue for disease and rot.

Very likely a case of anthracnose, a catch-all term for several different fungal pathogens that result in an assortment of leaf spots and early leaf drop. These tend to be highly weather related and high heat, high humidity and heavy rains can all contribute to the cause. But they are generally considered to be mostly cosmetic and seldom do any significant damage to an established tree. Control or a specific treatment is generally not warranted. Just clean up and dispose of ALL the fallen leaves to prevent spreading or overwintering the fungal spores on your property. And while probably not necessary, you can use a dormant oil spray in winter to smother any spores thay may be lurking on any stems or branches.