Although we don't see an obvious cause of decline in the photos, we can share some ideas, and recommend you work with a certified arborist who can evaluate the tree in person. Arborists won't always be able to make a concrete diagnosis, especially since tree decline sometimes begins months or even years prior to any symptoms manifesting (which can obscure some of the original indicators of a problem), but they can also look for potential sources of tree stress. They won't be able to treat every condition, but can look for indications of wood decay, prior branch or trunk injury, insect presence or fungal infections.

The growth on the bark of photo #9449 looks like a wood decay fungus. A few fungi can infect and kill live wood, but many are opportunists, instead colonizing wood already weakened, injured, and/or dying, and decaying it further without actively causing infection in nearby live wood. Some occupy the middle-ground, taking advantage of accessible dying wood and later moving into healthy wood. None will be curable, though an isolated patch of wood decay can be pruned off, if it hasn't invaded the trunk.

A thinning (sparse foliage) canopy could indicate declining roots, trunk injury, or a heavy insect outbreak (like scale insects, though we can't see them in the photos). Root decline can arise from the flooding or over-saturation of the soil in the tree's root zone (does anything deposit extra water in that area, like a change in grade or a nearby roof downspout outlet?), drought without supplemental irrigation, or digging damage from construction or utility work. If none of the above apply, was any herbicide (weed killer) used on the lawn around the tree? If so, did that product contain the active ingredient dicamba? That particular herbicide component is risky to use around tree and shrub roots since it can be absorbed and affect growth, though someone would probably have to apply it heavily to cause this degree of damage.

Trees can decline for a wide variety of reasons, some chronic (they may struggle for years before any problem is evident, especially once something pushes them over the edge of tolerance) and some acute, like a lightning strike. While reversing decline isn't always possible, sometimes intervention can prolong a tree's life for a few years/decades. Dying and dead trees do still provide lots of wildlife value, and in locations where their eventual fall won't damage anything, they can be left standing to disintegrate on their own. You can also use the scaffold of bare branches to grow a native vine up the natural support if you prefer to make it more decorative. (When the tree eventually did fall in that situation, the vine could be retrained onto another support structure.)

Maple and several other tree species can contract anthracnose fungal infections, but they are usually not a serious impact on a tree's health (especially those that are not saplings) despite sometimes causing drastic (but temporary) symptoms. Maple anthracnose is not the same exact fungal organism as the agent causing oak anthracnose or other variants of this disease, and they don't move from one host to another of a different species.

Miri



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